# The Commonwealth of Massachusetts Department of Food and Agriculture State Reclamation and Mosquito Control Board 100 Cambridge Street, Boston 02202 J.Kenney DFA Chairman Margaret Havey, Se cretary G.Gonyea DEP 617-727-3000 X 137 C.Burnham DEM 

### October 14, 1998 Enclosed is the "final" Generic Environmental Impact Report (GEIR) for the Massachusetts Mosquito Control Projects. The use of quotation marks around "final” denotes the Board's intention that there never will be an actual final version of this report. It is our goal to update this document on a yearly basis as new ideas and approaches to mosquito control become known, new pesticides or equipment come on the market or improved techniques are made available. This GEIR will become a living document, which will change and improve over the years, rather than be a static report becoming outdated in a few short years. As these improvements come to the Board's attention, and are reviewed and found to be valid and useful, addendum will be issued in order to continually update the report.

Yours truly,
John Kenney ChairmanTABLE OF CONTENTS

I . CERTIFICATE OF THE SECRETARY OF ENVIRONMENTAL AFFAIRS 1-5 II. EXECUTIVE SUMMARY 6-34 III. INTRODUCTION, HISTORY, CURRE NT ORGANIZATION, AND PRACTICE OF MOSQUITO CONTROL IN MASSACHUSETTS 35-97 A. Legislation and Regulation 1. Overview 2. State Laws a. M.G.L. Chapter 252 as currently amended - Improvement of Lowlands. b. M.G.L. Ch. 132B -- Pesticide Control Act (From the Code of Massachusetts Regulations 333 CMR 2.00 -10.00) c. 333 CMR 10.03 (21-23) - Amendments of 1983. d. M.G.L., Chapter 91. Sections 1-63 -- Waterways e. M.G.L., Chapter 40. Section 5 - Boards of Health and Supervision. f. M.G.L., Chapter 131. Section 40 - Wetlands Protection Act. g. Section 40A of Chapter 131. Inland Wetlands Restriction Act. Section 105 of Chapter 130. Coastal Wetlands Restriction Act. h. M.G.L., Chapter 131A. Massachusetts Endangered Species Act. i. M.G.L., Chapter 132A. Sections 13-16, 18 of Ocean and Coastal Sanctuaries Act j. Acts of Enabling Legislation Establishing Mosquito Control Projects 3. Federal Laws a. Section 401. Clean Water Act: Water Quality Certification. b. Section 404. Clean Water Act (1972). c. Endangered Species Act. B. Current Mosquito Control Programs in Massachusetts 1. Formal Mosquito Control Projects 2. Non-Member Communities. 3. Other Programs a. Department of Environmental Management b. Department of Public Health c. Federal Lands d. Private Reserves. C. Historical Overview of Mosquito Control Practices in Massachusetts 1. Practices prior to 1980 2. Transitioning: from 1980 to 1995. D. Current Mosquito Control Strategies in Massachusetts 1. Overview 2. Current Practice a. Saltmarsh Mosquitoes b. Inland Freshwater Wetlands c. Irrigated and Other Man-Made Reflood Habitats d. Urban Habitats 3. Current Policies a. Requests for Control b. Documentation for Control Implementation c. Selection of Control Strategies d. Evaluation of Efficacy e. Public Participation E. Eastern Equine Encephalitis 1. Responsibility for Surveillance and Control. 2.. Effect of EEE on ProjectsIV. DESCRIPTION OF MOSQUITO SPECIES AND ABATEMENT HABITATS 98-116 A. Mosquito Species 1. General biology of Massachusetstts mosquitoes 2. Salt marsh mosquitoes 3. Freshwater mosquitoes a. Aedes canadensis b. Aedes vexans c. Additional Aedes species d. Culex species e. Culiseta species f. Coquillettidea perturbans g. Other freshwater species B. Habitats in which mosquito control takes place 1. Coastal Wetlands a. Marine b. Brackish 2. Inland Wetlands 3. Surface Water Bodies a. Lakes and Ponds b. Rivers and Streams 4. Recharge Areas a. Wetland b. Upland 5. Upland Areas 6. Agricultural Areas, with emphasis or sensitive areas such as apiaries and organic farms. 7. Sensitive environments a. Urban b. Recreation c. Sensitive individuals d. Public and Private Wildlfie Refuges and Conservation Areas e. ACEC and areas with rare or endangered species f. Water supplies C. Mosquitoes as disease vectors. 1. Easten Equine Encephalitis 2. California Encephalitis vectors 3. Dog heartworm V . CURRENT ABATEMENT STRATEGIES AND THEIR IMPACTS 117-219 A. Chemical Control 1. Overview of Chemical Control a. General Toxicity of Pesticides b. Pesticides used for Mosquito Control in Massachusetts c. General Properties of Registered Mosquito Control Insecticides in Massachusetts, 1996 d. Pesticide Handling and Application 2. Larvicides a. Biologicals: Bti and B. sphaericus b. Methoprene c. Oils d. Others 3. Adulticides a. Pyrethrum and Synthetic Pyrethroidsb. Malathion B. Biological Control. 1. Introduction 2. Predators a. Introduction b. Vertebrate predators c. Invertebrate predators 3. Parasites and Pathogens a. mermithid nematode parasites b. Microsporidia c. Fungal Pathogens c. Bacterial pathogens d. Viral Pathogens 4. Pest Species Manipulation a. Sterile Insect Technique b. Incompatibility c. Chromosomal Aberrations d. Competitive Displacement 5. Other Control Approaches a. Trap out techniques. b. Repellents. C. Physical Control 1. Types of Habitat Modification a. Open marsh water management (OMWM) b. Other Modification Strategies c. origination of Requests for Physical Control 2. Ecosystem changes of non-target biota as a result of physical controls. a. Salt Marsh . b. Freshwater Wetlands (exclusive of Vernal Pools) c. Vernal Pools. d. Rare and Endangered Species. D. Food Web Effects of Mosquito Control E. No Program VI. MOSQUITO CONTROL INTEGRATED PEST MANAGEMENT 220-236 A. Definition of IPM as it relates to mosquito control B. Aspects of IPM currently in place in Massachusetts mosquito control programs VII. STANDARDS FOR MOSQUITO CONTROL 237-244 A. General policy regarding standard mosquito-control procedures B. Standards for Monitoring and Control 1. Larval Mosquito Populations a. Larval indentification b. Pre-control larval monitoring c. Post-control monitoring d. Additional water management requirements e. Pre-hatch work 2. Adult Mosquito Populations a. Monitoring for adulticiding b. Further notes on complaint calls c. Adult identification d. Post-adulticide monitoringC. Standards for Physical Control 1. Source Elimination a. Tires b. Blocked drainage c. Residential problems d. Drainage basin design 2. Source Maintenance a. Stormwater runoff and ditch maintenance b. Saltmarsh ditching c. Waste disposal 3. Source Reduction a. Open marsh water management b. Freshwater wetlands c. Cattail control D. Standards for Biological Control 1. Larvivorous fish 2. Other biological control agents E. Standards for Public Noltification, Public Awareness and Education 1. Public Notification 2. Public Awareness and Education 3. Staff Development F. Standards for EEE M onitoring and DPH Liason 1. Role of programs in EEE Surveillance 2. Standard Operating Procedures during EEE Problem. VIII. SUMMARY AND RECOMMENDATIONS 245-250 I X. WRITTEN COMMENTS ON GEIR 251 A. Comments on Notice of Project Change (1996). B. Comments on Spring 1997, Rough Draft. C. Comments on Final Rough Draft (1997-98). X. LITERATURE CITED 252-260 APPENDICES: A. Questionnaires, 1986 and 1996 261 B. DPH EEE Program 262-269 C. Sample Labels and Material Safety Data Sheets for pesticides currently in use 270 D. North East Massachusetts MCP Standards for Open Marsh Wa ter Management 271 E. Stormwater Management 272-274 F. North East Massachusetts MCP Standards for Ditch Maintenance 275 G. Educational Flyers about Mosquito Control 27 6 H. Preparer qualifications 277-278

### CERTIFICATE OF THE SECRETARY OF EN VIRONMENTAL AFFAIRS ON THE GENERIC ENVIRONMENTAL IMPACT REPORT
PROJECT NAME Mosquito Control Program PROJECT MUNICIPALITY Statewide PROJECT WATERSHED Statewide EOEA NUMBER 5027 PROJECT PROPONENT State Reclamation & Mosquito Control Board DATE NOTICED IN MONITOR: October 25, 1998 As the Secretary of Environmental Affairs, I hereby determine that the Generic Environmental Impact Report (EIR) submitted on this project adequately and properly complies with the Massachusetts Environmental Policy Act (M.G.L. c. 30, ss. 61- 62H ) and with its implementing regulations (301 CMR 11.00). On September 23, 1996 the Secretary of Environmenta l Affairs issued a Cert ificate on a Notice of Project Change filed by the State Reclamation and Mosquito Control Board (SRMCB) requiring that a Generic Environmental Impact Report (GEIR) be completed, for mosquito control in the Commonwealth. The Certificate contained an extrem ely detailed scope for the GEIR, developed in coordination with SRMCB. This GEIR, by responding to all of the items in that scope, provides an extremely useful summary of' current data, practices, and standards for mosquito control statewide. In particular, the GEIR establishes that Open Mars h Water Management (OMWM) shall serve as the preferred practice for physical contro ls in salt marshes. The GEIR also highlights certain areas in which further research will be necessary, and it. 1 - The State Reclamation and Mosquito. Control Bo ard (SRMCB) is comprised of one representative each from the Departments of Environmental Management, Environmental Protection and Food and Agriculture proposes a system of annual updates, offering continue d opportunities for review and comment on new information and proposals. Introduction The SRMCB oversees nine organize d mosquito control projects (Ber kshire County, Bristol County, Cape Cod, Central Massachusetts, East Middlesex County' Norfolk County, Plymouth County, Suffolk County and the North East Massachusetts Mosquito Control and Wetlands Management District) and appoints the Board of Commi ssioners for each project. These mosquito control projects have a total of 157 participating communities, primaril y coastal. Thus, the focus of th e GEIR and this Certificate are primarily upon salt marshes and thei r attendant pest mosquito problems. The remaining nonparticipating communities, mostly located in the central portion of th e state practice no mosquito control, hire private contractors or have their own co mmunity-based mosquito control operations (e.g., the local public works department or health board). The intent of the GEIR was to gather, in single document information on methods of mosquito control and eradication in Massachusetts, and the enviro nmental impacts of those methods. The GEIR has accomplished the goal of disseminating information on current mosquito control practices, and it has established the basis for viewing OMWM as the pr eferred control technique in salt-water marshes.

### Comments received from the Depa rtment of Environmental Protec tion (DEP) and the Division of Fisheries and Wildlife (DF&W), in particular, w ill provide a good basis for future GEIR updates. However, the GEIR falls short of the ambitious goa l of providing the basis fo r all future mosquito control projects implemented by th e County Mosquito Control Projects. The SRMCB and, the GEIR acknowledge that additional study and research work is necessary to truly document ~he effectiveness of mosquito control techniques and their impact on the environment, particularly as they relate to freshwater projects. The report concludes that it will take a renewed and concerted effort, involving additional resources, to complete a mosquito control program "maste r guidance document" that best serves the public and protects the environment. To that end, the SRMC B plans to update the GEIR on a yearly basis as new ideas and approaches to mosquito control become known. Saltwater Marsh Regulation Issues and MEPA Established mosquito control projec ts are generally exempt from th e Massachusetts Wetlands Protection Act (MWPA). However, Section 401 of the Federal Clean Water Act re quires applicants wishing to discharge dredged of fill materials to obtain a certification or waiver from their state water pollution control agency. A Section 401 water quality certification is treated as a state permit for the purposes of establishing MEPA jurisdiction. Theref ore, for projects involving new di tching such as that required for Open Marsh Water Management (OMWM), the MC proponent has been obliged to file an Environmental Notification Form (ENF) for, pr ojects affecting at least 1,000 square feet of salt marsh or 5,600-sf- of bordering-vegetated wetlands (BVW). Th e MEPA regulations require the filing of an Environmental Impact Report (EIR) for any particular work site that might requ ire the alteration of one or more acres of salt marsh or BVW. In November 1995 the then-Essex Co unty Mosquito Control Project ( now the Northeast Massachusetts Mosquito Control and Wetlands Management District ) filed an ENF requesting a waiver from the EIR requirement- (EOEA #10567). Based on a number of "findings and conditions" discussed below, a waiver from the EIR requirement was grante d in February 1996. The most significant of those findings .was that the Essex County Mosqui to Control Project established "Standards for Open Marsh Water Management" which were endorsed by the Environm ental Protection Agency, the National Marine Fisheries Service, the Massachuse tts Audubon Society and others. These standards are widely viewed as the least harmful to the environment (of the various control techniques) and mo st efficient non-pesticide method for controlling salt marsh mosquitoes. The-proponent also committed-' to conduct a review of ten years of OMWM in Essex County to provide a basis for comparison and evaluation of mosquito control effectiveness and impact to the environment. It is generally recognized that the principal concern associated with OMWM arises" from the disposal of the dredge material on the marsh and the potential for invasion of upland plants (particularly Phragmites ) that can occur with even slight elevation increases (i.e." 1-2 inches). Open marsh water management (OMWM) proj ects are now underway in Essex (EOEA #10567), Norfolk, and Plymouth counties and are being expanded to include all problem marshes in those counties. The need to convert grid ditch systems is likely to continue and the salt marsh alterations will likely exceed the one-acre EIR threshold at se veral locations. Based on the success of OMWM, The establishment of "Standards for Open Marsh Wate r Management," the conclusions of this GEIR, - and the commitment to continue to monitor the effectiveness of OM WM on the control of mosquitoes and, its impact on the environment, I am proposi ng, in a -forthcoming issue of the Environmental Monitor, to publish a Draft Record of Decision that would modify" the ENF and EIR thresholds for OMWM projects2, subject, ata minimum, to the followi ng standards and conditions:

### 2 The MEPA regulations at Section 11.01 (2) (b)"(3) under" Review Thres holds" state, in part, that the review thresholds do not apply to..." a project that is consistent with a Special Review Procedure review document, or other plan or document that has been prepared with the express purpose of assessing the potential environmental impacts from future Proj ects, has been reviewed under or approved by any Participating Agency, unless the' filing of an ENF and an EIR was required by a decision of the secretary on any such review doc ument, plan or document." * That the Northeast Massachusetts Mosquito Cont rol and Wetlands Management District "Standards for Open Marsh Water Management" be used as the statewide standard for OMWM projects. * That the salt marsh be inventoried for the presen ce of rare and endangered species as determined by the Natural Heritage and Endangered Species Program (NHESP) habitat maps. If a project falls within such an area, NHESP will then determine if the area to be altered is an actual wetland habitat for rare species. * Compliance with Section 401 of the Federal Clean Water Act and Federal Coastal Zone Consistency. * Improved record keeping with re spect to treatment location, t ype, efficacy and post treatment monitoring. For example, there are ol d ditches that still effectively c ontrol mosquitoes therefore their effectiveness should be monitored prior to going ahead with OMWM. MC Projects Impact on Freshwater Wetlands Freshwater wetlands are the dominant system in which freshwater physical control take place. Typically, this work consists of maintaining (i.e., moving blockages from previously ditched areas) existing ditches designed to remove standing wa ter from the wetland. Though reducing standing water reduces mosquito breeding, there has been little research concerning the ove rall effects of these alterations on the modified wetland. Therefore, increased efforts are necessary to examine the environmental effects of draining surface water from wetlands. As stated above, most of the freshwater mosquito control projects are geared to removal of blockages, be they natural or influenced by man, in wetland areas earlier identified as significant mosquito breeding habitats. These projects us ually are classified as maintenance projects and are therefore exempt from MEPA review pursuant to Section 11.01 (2) (b) (3). However, there is a significant amount of work that needs to be completed in order to determin e whether such work is cost effective, and whether a specific alternative is the one least damaging to the environment. As the report acknowledges there has been no study to date of the costs and benefits of Massachuse tts mosquito control programs. However, this work has been done in other states, most notably New Jersey, which should be helpful in answering the following questions raised in the GEIR: 1) Establishing substantiv e human annoyance thresholds 2) Documenting how human activ ity patterns relate to Human Annoyance Thresholds (HAT) and economic factors; 3) Determining th e cost/benefit of control; and 4) Correlating densities of immature mosquito (i.e., larvae) with fu ture levels of biting annoyance. These issues should be addressed and reported on in future GEIR updates. EOEA is prepared to help in this regard.

### Standards for Freshwater Wetland Physical Control The GEIR indicates that the SRMCB still needs to determine the appropriate control measure standards for MC projects in freshwater we tlands (described in the report as Upland Water Management operational procedures). These standards will need to The current provocations for execution of mosquito control tec hniques are generally as follows: 1. Larval populations - by dip count (up to 20 per sampling area) and based on the population #s/10 or 5 dips then a decision is made to either use a pesticide or water management strategy. 2. Adult populations - No adulticiding is to take pl ace at a regularly scheduled or prescribed time or place. Instead spraying is done based on annoyances, such as five bites per night; more than one landing per minute; or two complainant calls per square mile of ar ea be coordinated with the DEP's Storm water Policy Handbook and Storm water Technical Handbook. In addition, many physical control projects lack adequate records, both with respect to the justif ication of a specific project, and with respect to site plans. Therefore, the SRMCB should work toward requiring better record keeping and notification practices, as discussed in the DE P comment (and the Coastal Zone Management letter for salt marsh alterations). Integrated Pest Management (IPM) The GEIR indicates that the strengths of the Massachusetts mosquito control IPM include the availability of and willingness to use least-toxic ma terials and willingness of existing control programs to try new strategies. In addition, a successful IPM program requires strong control programs and good pretreatment monitoring. The weakne sses of the IPM have been linked to a lack of funds for research and implementation and a lack of basic ecological data on the effects of contro l strategies in use or being planned. I do note that all of the pesticides -(larvicides and pest icides) used by MC projects have been approved by and are registered with the US Environmental Protection Ag ency. Given the rigorous process to gain market approval for a pesticide as we ll as the evolving nature of pesticide development, I agree with the conclusions of the GEIR that, for now, advances in reducing the risk of chemical use must come from improved targeting and increased us e of water management and/or biological control techniques as encouraged by the IPM technique. Eastern Equine Encephalitis (EEE) The Massachusetts Department of Public Health (D PH) is responsible for surveillance for EEE Virus, risk assessment, public information and educatio n on EEE disease. DPH is also responsible for recommendations for wide aerial vector control, in terventions. DPH published its "Vector Control Plan to Prevent Eastern (Equine) Encepha litis" on (August 7, 1991). That protoc ol will govern when the next EEE outbreak occurs. The DPH has also developed a monitoring program that should bring EEE into the IPM framework. I urge that this work continue in order to avoid the adversity that accompanied the 1990 aerial spraying. GEIR Recommendations and Conclusions In addition to the issues discussed above, GE IR updates should emphasize how MC programs will incorporate the IPM strategy of keeping human annoyance below specified thresholds. Standards for control methodology should favor source reduction (e.g., OMWM in salt marshes) whenever possible, and employ larvicide control only when source reduction is not effec tive. Projects should work closely with the DEP water quality certification pr ogram and the NHESP to improve notices and documentation, and to minimize negative impacts of source reduction.

### It is clear that the SRMCB and th e MC projects have a good handle on their data and research needs. The stumbling block to successful comp letion of the analysis appears to be primarily fiscal in nature. I am pleased with the SRMCB's commitment to provide yearly updates, and I expect that issues brought forward in this Certificate, as well as the comments from the DEP and DF&W, will be addressed in the first yearly update. The SMRCB should meet with ME PA prior to finalizing the content of the GEIR update.

## State of Massachusetts Generic Environm ental Im pact Report on Mosquito Control Executive Summary

I. Intr oduct i on A Gen e ric En v i ro n m en tal Im p act Rep o r t (GEIR), co v e rin g m o sq u ito co n tro l activ ities with in th e State of M a ssachuset t s , was m a ndat e d under th e provi si on of M a ssachuset t s General Laws C h apt e r 30A Sect i on 61 by
th e M a ssachuset t s Envi ronm ent a l Pol i c y Act (M EPA) R e gul at i on 301 C M R10.32(5)(b) adopt ed on January 25, 1979. The St at e R ecl am at i on and M o squi t o C ontrol B o ard (SR M C B ) , th e st at e agency th at oversees al l l o cal and regi onal m o squi t o control program s i n M a ssachuset t s , adm i ni st ers th e GEIR . The SR M C B consi s t s of one representative each from the Departm e nts of Environm enta l Managem e nt, Environm enta l Protection, and Food and Ag ricu ltu re. Th e latter m e m b er p r esen tly serves as the Chairm an of the Board. Thi s GEIRserves fi ve purposes: 1

. It p r o v i d e s a h i sto r ic su m m a ry o f all p u b lic activ ities in Massach u s etts related to m o sq u ito co n tro l, i n cl udi ng an account of how m o squi t o control i n M a ssachuset t s has rapi dl y evol ved over th e past ten years. 2. It descri bes and quant i f i e s M a ssachuset t s m o squito problem s and assesses the effectiveness of past and current control program s. 3. It assesses th e real and pot ent i a l envi ronm ent a l i m pact s of past and current control pract i ces and descri bes and eval uat e s al t e rnat i v e strat e gi es. 4. It gives an IPM fram e work for m o squito c ontrol i n M a ssachuset t s and provi des a seri es of operat i onal st andards for m o squi t o control pract i ces. 5

. It m a k e s reco m m e n d a tio n s relativ e to th e fu tu re organi zat i on and pract i ce of m o squi t o control i n M a ssachuset t s .II. Hi st ory , Organi zat i on and Pract i ce Of M o squi t o C ontrol In M a ssachuset t s A. Legi sl at i on and R e gul at i on 1. State Laws The fi rst Act of m a jor i m port a nce i s C h apt e r 252 of th e M a ssachuset t s General Laws (M GL), whi c h est abl i s hes th e St at e R ecl am at i on and M o squi t o C ontrol B o ard (SR M C B ) and procedures for creat i ng l o cal
control project s. As now am ended, 252 i n cl udes th e i m port a nt earl i e r provi si ons of C h apt e rs 199 and 699 of th e Act s of 1960. The word i m provem e nt (o f wetlan d s ) as freq u e n tly u s ed in th e n a rrativ e fo r th is Act is m i slead in g . M odi fi cat i on or al t e rat i on woul d have been a m o re appropr i a t e and object i v e t e rm t o descri be wet l a nd drai nage and fillin g activ ities. The second Act is the W e tlands Protection Act (Chapter 131 of MGL) which regulates activities in the aquat i c and bracki s h habi t a t s where m o st m o squi t o es breed . However, organi zed m o squi t o control i s general l y

exem pt

from th e provi si ons of th i s St at e Law. Hence, th e Federal Clean W a ter Act as adm i nistered by the U. S. C o rps of Engi neers, i s th e pri n ci pal regul at i ng m echani s m fo r m o sq u ito -co n tro l alteratio n s in wetlan d s . Reg a rd less of th e general exem pt i on, m o squi t o control i s not exem pt

from checki ng for th e presence of rare and endangered speci es th rough th e Massach u s etts Natu ral Heritag e Atlas , wh ich lists estim ated h ab itat m a p s fo r all rare an d endangered speci es as devel oped by th e Natu ra l Heri t a ge Endangered Speci es Program (NHESP). The th i r d Act whi c h i n fl uences m o squi t o control i n th e Endangered Speci es Act (C hapt er 131A of M G L) whi c h prohi bi t s th e “t aki ng” of rare and endangered speci es. It al so prot ect s “si gni fi cant habi t a t s ,’ requi ri ng a perm i t request for any work done i n such areas. The fourth Act of im portance to m o squito control activities is the Pes ticide Control Act (Chapter 132B of MGL) wh ich reg u l ates p e sticid e u s e b y m o sq u ito co n tro l p r actitio n e rs. Th ree ad d itio n a l Acts h a v e th e p o t en tial to im p act m o squi t o control

. M

. G.L., C h ap. 91. Sect i ons 1-63 -- W a terways d o e s n o t d eal sp ecifically with m o sq u ito co n tro l b u t it d o e s co v e r v a riety o f activ ities asso ciated with wet l a nds. M o squi t o control i s speci fi cal l y exem pt ed from th e provi si ons of Sect i ons 19A, 59 and 59A of th i s l a w but not from other provi si ons. M

. G.L., C h apt e r 40. Sect i on 5 - B o ards of Heal th and Supervi s i on, cont ai ns cl auses th at address th e i ssue of appropri a t i ng m oney at th e muni ci pal l e vel for m o squi t o abat em ent
. M

. G.L., C h apt e r 132A. Sections 13-16, 18 -- Ocean and Coastal Sanctuaries Act, S e c ti o n 1 4 , i s d e s i g n e dt o i s t o p r o t e c t d e s i g n at e d ocean sanctuary from any "...exploitation, development, or activity that would seriously alter or otherwise endanger theecology or the appearance of the ocean, the seabed, or the subsoil (of the sanctuaries), or the Cape Cod National Seashore." Mosquito control does not take place in these sanctuaries. 2. Federal Laws Federal laws which directly im pact on m o squito control activities are Sections 401 and 404 of the Clean W a t e r Act and th e Endangered Speci es Act

. Al l other fe deral restri ct i ons governi ng wet l a nds and pest i c i d es are covered by M a ssachuset t s l a ws whi c h i m pos e restri ct i ons and requi rem e nt s th at are equal t o or great er th an those i n

com p arable federal law. The excepti on in the case of Section 404 arises because the state laws governing the di t c hi ng of wet l a nds exem pt

m o squi t o control but th e Federal C l ean W a t e r Act does not

. Section 401 (Clean W a ter Act: W a ter Quality Certifi cation) requires applicants wishing to discharge d r ed g e d o rfill m a terials to o b t ain a certificatio n o rwaiv er fro m th eir state water p o llu tio n co n tro l ag en cy (M assachuset t s B u reau of R e source Prot ect i on, Di vi si on of W e t l a nds and W a t e rway s). The U. S. Army C o rps of En g i n eers will n o t p e rm it a m o sq u ito -co n tro l p r o j ect th at d o e s n o t h a v e a water q u a lity certificatio n . Section 404 of the Clean W a ter Act (1972), calls for a system of perm itting to be carried out by the U.S. Army C o rps of Engi neers wi th a revi ew of al ! perm i t app l i cat i ons by appropri a t e st at e and federal agencies. The activities that involve m o squito c ontrol which require a perm it under S ection 404 are cutting or clearing new

m o squi t o di t c hes i n t i d al areas bel o w m ean hi gh wat e r and/ or pl aci ng m a t e ri al excavat ed from exi s t i ng or new di t c hes on sal t m a rshes or freshwat e r wet l a nds. The Endangered Speci es Act i s desi gned t o prot ect threatened and endangered species as listed on the Natu ral Heritag e Atlas . To dat e , several program s have had t o m odi fy th ei r control effort t o t a ke i n t o account endangered speci es. B

. C u rrent M o squi t o C ontrol Program s i n M a ssachuset t s 1. Form al M o squi t o C ontrol Project s Of th e 351 Towns i n M a ssachuset t s , 157 (or 44.7%) current l y bel ong t o th e 9 organi zed m o squi t o control project s. Each project i s m a naged by a superi nt endent who i s hi red and supervi s ed by a B o ard of C o m m i ssi oners represent i ng th e t o wns i n cl uded i n th e project . B o ard m e m b ers are appoi nt ed by th e B o ard of R ecl am at i on for desi gnat e d t e rm s (usual l y 3-5 y ears). B o ards general l y m eet once or t w i ce m onthl y t o authori ze m a jor expendi tu res and t o revi ew pol i c y and program progress. The SRMCB is m a de up of three m e m b ers, one each from the Departm e nts of Food and Agriculture,Environm ental Managem e nt and Envir onm ental Protection, and exercises re sponsibility over all 9 projects. All projects have a Board of Com m i ssioners appointed by the SRMCB. They represent the various towns within each project and exerci se general control over th e project

.

The Ni ne M o squi t o C ontrol Project s of M a ssachuset t s are B e rkshi r e C ount y , B r i s t o l C ount y , C a pe C od, C e ntral M a ssachuset t s , East M i ddl esex C ount y , Norfol k C ount y , Pl y m outh C ount y and Suffol k C ount y M o squi t o C ontrol Project s and th e North East M a ssachuset t s M o squ i t o C ontrol and W e t l a nds M a nagem e nt Di stri ct (form erl y Essex C ount y M C P). Nantucket conduct s sal t m arsh m o squ i t o control i n cl udi ng l a rvi c i d i ng and open m a rsh wat e r

m a nagem e nt
. 2. Other State Agencies The St at e Di vi si on of Forest s and Parks di scont i nued i t s own m o squi t o control program i n . The North East Massachusetts Mosquito Control and W e tlands Restora tion District (NEMMCW R D) adulticides Salisbury Beach State Park and Bradley Palm er State Park in Ham ilton as the need arises. The Massachusetts DPH is responsible for surveillan ce for EEE Virus, risk assessm ent, public inform ation and education on EEE disease, as well as providing advice to the State Reclam ation and Mosquito Control Board on appropriate risk m a nagem e nt for EEE. DPH is also re sponsible for recom m e ndations for wide area aerial vector control interventions in the event of an EEE Public Health Em ergency. 3. Federal Propert y No m o squi t o control i s carri ed out by th e U.S. Depart m e nt of Int e ri or on any governm e nt -owned l a nd i n M a ssachuset t s . The C a pe C od Nat i onal Seashore i s perhaps th e U.S. Park Servi ce propert y wi th th e m o st si gni fi cant m o squi t o popul at i ons. Park Servi ce bi ol ogi st s have conduct e d th ei r own studi es on th e envi ronm ent a l im pact of Cape Cod m o squito control activities (Portnoy 1983, 1984a, 1984b) in adjacent estuaries and have l obbi ed agai nst cert a i n di t c h cl eani ng pract i ces on envi ronm ent a l grounds. The East M i ddl esex M C P has been control l i ng m o squi t o es i n Great M eadows Nat i onal W i l d l i f e R e fuge si nce 1987. Annual aeri a l B t i appl i cat i ons t a rget ed agai nst spri ng Aedes speci es began i n 1987 and appl i cat i ons t o control Aedes vexans began i n 1990

. The National Park Service reservati on area (Paul Revere' s Ride) in East M i ddl esex C ount y has been decl ared off l i m i t s t o any m o squi t o control act i v i t y (by East M i ddl esex M C project ) except for ditch cleaning. The NEM M C W R D has com p l e t e d OM W M project s on th e Parker R i ver W i l d l i f e R e fuge.C

. Overvi ew of M o squi t o C ontrol Pract i ces i n M a ssachuset t s Developm ent and tourism along the Massachusetts coast is predicated on an ability to control the hoards of saltm arsh m o squitoes. Massive hand-ditching projects in East Coast m a rshes that took place during the W P A program s of th e great depressi on. These di t c hi ng schem e s, wh ile q u ite effectiv e in red u c in g saltm arsh m o sq u ito es, were engineered to m a ke work rather th an for opt i mum bi ological efficiency. Earl y sal t m arsh m o squi t o control project s, such as th e one on C a pe C od i n th e 1930' s, were organi zed pri o r to th e av ailab ility o f syn th e tic p e sticid es fo llo win g W o rld W a r II an d th ese p r o j ects ex p a n d e d an d m a in tain ed th e W P A-dug di t c h sy st em as th ei r m a i n strat e gy for m o squi t o control

. Aft e r DDT, B H C , and other organochl ori n e pesticides becam e available, they were used to both suppl em ent larval control and, for the first tim e, to conduct residual spraying for adults. Aerial application of these pesticides becam e com m onplace in the 1950' s and early 60' s. The com m e rcial m o squito cont rol oil, Flit ML0, was introduced and widely used during the 70' s. Ch em ical co n tro l in fresh water m a rsh e s fo llo wed a sim ilar p a ttern to th at in salt m a rsh e s. Treatm e n t o f
cat ch basi ns, fi rst wi th oi l s fol l o wed by organochl ori n es and organophosphat e s, dat e s back t o th e begi nni ng of m o st M a ssachuset t s project s. Ph ysical co n tro l was lim ited to d r ain a g e m a in ten a nce and expansi on i n both salt m a rshes and freshwater areas. B i ol ogi cal control was not conduct e d. B y th e earl y 1980s, concerns over pest i c i d e use and we t l a nds l o ss began t o encroach on m o squi t o control

. Gri d di t c hi ng for l a rvae and m a l a th i on for adul t s was no l onger a desi rabl e one-t wo punch. C ontrol tr ends duri ng th e eig h ties an d early n i n e ties in clu d e d : ch an g i n g fro m trad itio n a l ch em icals, su ch as Ab ate an d Flit MLO, to Bti and m e thoprene for l a rval control , changi ng from m a l a th i on t o perm ethri n or resm ethri n for adul t control , and changi ng from open t i d al di t c hi ng t o open m a rsh wat e r m a nagem e nt for sal t m arsh m o squi t o control

. So u r ce red u c tio n rem a in ed a m a in stay o f th e p r o j ects d u r in g th is tim e p e rio d

. Co astal co m mu n ities sh ifted away from di t c h m a i n t e nance t o wards open m a rsh wat e r m a nagem e nt . An em ergi ng di ffi cul t y for control program s i s th e ri se i n wet basi ns m a ndat e d by st orm w at er runoff regul at i ons. The eval uat i on of control effect i v eness by project s rem a in ed a co m b in atio n o f p u b lic co m p lain ts, ad u lt
count s, l a rval count s, and cases of hum an di sease. C h em i cal control , i n cl udi ng Ba cillu s product s and IGR s , and source reduc t i on, i n cl udi ng open m a rsh wat e r

m a nagem e nt , now dom i n at e m o squi t o control i n M a ssachuset t s . Aeri al appl i cat i ons of l a rvi c i d e have been used byseveral program s and are i n creasi ng. B i ol ogi cal control ha s not been em phasized except to th e ex ten t th at OMW M creat es condi t i ons under whi c h bi ol ogi cal control operat e s. Publ i c educat i on i s a m i nor com ponent of m o st program s. Saltm arsh m o squitoes are the prim ary target of coastal program s, wh ereas i n l a nd program s t a rget spri ngbrood and sum m e r-refl ood Aedes

. Coquillettidea perturbans is restricted b y larv al h ab itat to areas n ear cattail

m a rshes but is a big problem in those ar eas. It com p licates control efforts b ecause controlling the larval stage with

m e thoprene is expensive and adulticidi ng provides only short-term control. Vect or m o squi t o es are not th e pri m ary t a rget s of M a ssachuset t s control program s, though project s can respond to requests for aid from DPH in tim es of EEE em ergencies. C u l i s et a mel anura l a rval popul at i ons m a y be i n ci dent al l y reduced by tr eat m e nt program s that target swam p areas. At present, policy issues revolve around wetlands pr otection, water quality pres ervation, and endangered speci es. A chroni c source of di scussi on i s m o squi t o control ’ s exem pt i on from m a ny of th e st at e-l e vel wet l a nds protection acts, m a king the Federal Secti on 401 W a ter Quality Certification (adm in istered at the state level) and the
st at e and federal Endangered Speci es Act s th e pri m ary m eans of “control l i ng” source-reduct i on work. St orm w at er runoff regulations have increased the num ber of wet basins (retention, wet detention) in m a ny areas, on occasion
creat i ng breedi ng habi t a t The EEE outbreak in 1990 highlighted a need for st ronger DPH policies regarding em ergency m o squito
control

. As a resul t , th e M a ssachuset t s Depart m e nt of Pu b lic Health p u b lish e d “Vecto rCo n tro l Plan to Prev en t Eastern (Equine) Encephalitis” (August 7, 1991) and im plem en ted an extensive Public Education Program in 1991.

The com b i n at i on of l a rge, affl uent hum an popul at i on (both perm anent resi dent s and vi si t o rs) and prol i f i c pest m o squi t o popul at i ons near M a ssachuset t s coast a l m arshes suggest s th at th e publ i c m a y al way s dem a nd control program s t o deal wi th th i s probl em . Open M a rsh W a t e r M a nagem e nt (OM W M ) project s now underway i n Essex, Norfol k , and Pl y m outh
count i e s are bei ng expanded t o i n cl ude essent i a l l y al l probl em m a rshes i n those count i e s. The tr end t o convert gri d

d itch system s to OMW M is lik ely to co n tin u e . There are cert a i n sal t m a rshes where ol d di t c hes are effect i v el y control l i ng m o squi t o product i on and perhaps where new OMW M activities m i ght actually disrupt the m a rsh m o re than m a intaining the status quo. Thus,OM W M pl ans shoul d not be aut o m a t i cal l y prescri b ed for every sal t m arsh wi thout fi rst exam i n i ng th i s i ssue. Larv icid in g is still carried o u t in salt m a rsh e s. Inadequate budgets, the inability to conduct m o re sour ce reduction work and a lack of applied research i n t o m o re envi ronm ent a l l y sound m o squi t o -control pract i ces cont i nue t o restri ct th e act i ons and effect i v eness of

m o squi t o control program s i n M a ssachuset t s . III. Current Abatem ent Stra tegies and Their Im pacts A. Chem ical Control Twent y -si x di fferent i n sect i c i d e formul at i on di stri but ed am ong fi ft een product l i n es were used for

m o squi t o control i n M a ssachuset t s bet w een 1993 and 1995 (Tabl e 1). Ei ght of th ese formul at i ons used B t i as th e active ingredient, five were m e thopren e-based, three were resm ethrin-based , two each were pyrethin-based or

m a lathion-based, and there were one each of tem e phos, isocte decanol, and m i neral oil. Of these, Acrobe (Bti) and Vectobac AS (replaced by 12AS) are no longer produced. Arosurf-MSF (Isoctadecanol) was off the m a rket for several y ears but i s now avai l abl e under th e nam e Agni que M M F . Abat e 4E was not used i n ei th er 1994 or 1995 and both th e M a l a th i on 10EC and th e R e sm ethri n product (EPA reg. # 4-339-53853) were used i n sm al l am ount s onl y Of th e in secticid es u s ed , all o f th e larv icid es were classed as Categ o r y IV (Categ o r y I is th e m o st to x i c, C a t e gory IV th e l east ) m a t e ri al s by EPA. B oni de M o squi t o Larvi c i d e, avai l abl e but not used, i s border l i n e bet w een Category III and IV. VectoLex CG, a new Bacillus sphaericus product, is Category IV. All adulticides are in Category III, with perm ethrin and resm ethr in having essentially replaced m a lathion. C h em i cal i m pact s i n cl ude acut e , di rect i m pact s t o t a rget and non-t a rget organi sm s, and chroni c or i ndi rect effect s t o t a rget and non-t a rget organi sm s. In general , acut e t oxi ci t y effect s are general l y easi e st t o m easure and avoi d, part i c ul arl y when th e organi sm i s l a rge and th e effect i s death. However, l e ss vi si bl e acut e t oxi ci t y , such asTabl e 1. C h em i cal s used i n M a ssachuset t s m o squi t o control , 1993 th rough 1995 Trade Nam e EPA Registration Ac tiv e % Activ e To x i city Oth e r Num b er Ingredi e nt (s) Ingredi e nt C l ass W a rni ng St at em ent s LARVICIDES Abat e 4E 241-132 Tem e phos 43 IV Acrobe a62637-1-241 B t i b IV Arosurf-M SF c 42943-8 Isooctadecanol 100 III Alto sid B r i quet s 2724-375-64833 M e thoprene 7.9 IV XR B r i quet s 2724-421-64833 M e thoprene 1.8 IV Pel l e t s 2724-448-64833 M e thoprene 4.0 IV Bactim o s B r i quet s 43382-3 B t i 10 IV Granul es 37100-43-2217 B t i 0.2 IV Pel l e t s 37100-42-2217 B t i 0.4 IV GB -1111 8898-16 Petr ol eum Hy drocarbons GB -1356 8898-16 Teknar HP-D 2724-365-64833 B t i 0.8 IV Vectobac AS 275-52 B t i IV 12AS 275-66 B t i 1.2 IV Granul ar 275-50 B t i 0.2 IV ADULTICIDES M a l a th i on 8EC 34704-119 M a l a th i on 8 III Perm anone 10EC 4816-688 Perm ethri n 10 III Perm anone 31-66 4816-740 Perm ethri n 31 III Resm ethri n 4-339-53853 Resm ethri n III Scourge 4+12 432-716 Resm ethri n 4 III ⎫ ⎧ RESTRICTED USE PB O 12 ⎬ ⎨ CLASSIFICATION Scourge 18+54 432-667 Resm ethri n 18 III ⎪ ⎪ Du e to acu te fish to x i city PB O 54 ⎭ ⎪ R e t a i l sal e t o and use onl y by ⎪ C e rt i f i e d Appl i cat ors or ⎪ persons under th ei r di rect ⎪ supervi s i on and onl y for those ⎪ uses covered by th e C e rt i f i e d ⎩ Applicators Certificate MATERIALS REGISTERED BUT NOT USED - LARVICIDES Alto sid Li qui d 2724-392-64833 M e thoprene 5 IV Li qui d C on 2724-446-64833 M e thoprene 20 IV B oni de M o squi t o Larvi c i d e 4-195 M i neral Oi l 98 III-IV Vect oLex C G 275-77 B. sphaeri cus 50 d IV MATERIALS REGISTERED BUT NOT USED - ADULTICIDE Fy fanon ULV 4787-8 M a l a th i on 95 III a No l onger m a rket ed b Ba cillu s th u r in g i en sis var . israelensis c Now m a rketed as Agnique MMFm e thoprene t oxi ci t y t o C h i r onom i d l a rvae i n duck-breedi ng habi t a t (SPR P 1996), m a y cause harm i n th e short t e rm , and, si nce i t oft e n goes unnot i ced, m a y be harm ful i n th e l ong run as wel l

. M o squi t o C ontrol Program s have l i m i t e d, but not rem oved, th e th reat of acut e i m pact s t o non-t a rget s by usi ng pest i c i d es th at are m o re speci fi c t o th e t a rget , l e ss t oxi c t o non-t a rget s, and/ or have a short e r persi s t e nce i n th e envi ronm ent
. The am ount of pest i c i d e used, as in the case of ultra-low-volum e sprays ve rsus m i st sprays, has also been reduced. C h roni c effect s th at m a y occur i n cl ude th e l ong-t e rm effect of th e chem i cal on t a rget s (devel opm ent of resistance to the chem ical) and non- targets (reduced reproductive success), and long-term effects caused by a change i n th e ecosy st em brought about by rem oval of th e t a rget organi sm . The current assum p t i on i s th at th e

m o squi t o es control l e d are those whi c h have escaped th e f ood web and whi c h, th erefore, m a y be el i m i n at ed wi thout undue ri sk t o th e food web i t s el f. That m o squi t o es ar e rem a rkabl y product i v e cannot be deni ed. That rem ovi ng

m illions of larvae from the food web of a salt m a rsh by th e application of Bti has no effect on that ecosystem deserves addi t i onal study , as does th e rol e of m o squi t o es in the ecosystem , and the eff ect of m o squi t o control on that ecosystem

. C ontrol personnel shoul d t a ke care t o avoi d chem i cal appl i cat i ons where m o squi t o l a rvae are not present or are present i n very sm al l num bers, shoul d use control m eas ures th at do not harm exi s t i ng predat or com p l e xes, and should lim it control to areas where control is necessary, a llowing natural cycles to con tinue in areas where hum an activ ity an d th e risk o f d i sease tran sm issio n is slig h t . On e arg u m en t m a d e in fav o ro f Alto sid is th at it d o e s n o t k ill
th e y oung l a rvae, l eavi ng th em avai l abl e as food for th e exi s t i ng predat or com p l e x. Barring the discovery of new m a teri als, both adulticiding and larvicidi ng are presently be conducted with the least risk im posing m a terials availabl e for the foreseeable future. Advances in reducing the risk of chem ical use

mu st therefore com e from im proved targeting and increaseduse of wat e r m a nagem e nt and/ or bi ol ogi cal control
t echni ques. B

. B i ol ogi cal C ontrol

. B i ol ogi cal control i n cl udes at t acks on th e pest speci es by other speci es and m a ni pul at i on of th e pest speci es itself. On ly th e fo rm er h a s b een u s ed in Massach u s etts. No te th at, fo r th e p u rp o s es o f th is GEIR, Bti, Ba cillu s sphaeri cus and m e thoprene are cl assi fi ed as chem i cal control s and open m a rsh wat e r m a nagem e nt i s cl assi fi ed as a physical control. A case can be m a de for classifying each of these strategies as a type of bi ological control. B i ol ogi cal control agent s are grouped i n t o th ree cat egori e s: predat ors, parasi t e s and pathogens. Predat orsi n cl ude both vert ebrat e s and i nvert ebrat e s and m a y at t ack both adul t and i m m a tu re st ages of m o squi t o es. In general , bi ol ogi cal control i s mu ch m o re feasi b l e i n m a nagi ng perm anent wat e r m o squi t o es th an t e m porary wat e r form s. Th ere are th ree b a sic strateg i es fo r u tilizin g all b i o l o g i cal co n tro l ag en ts: 1 ) in creasin g ex istin g n a tu ral

enemy popul at i ons by habi t a t i m provem e nt , 2) one-t i m e i n tr oduct i on of sust ai nabl e exot i c agent s from other regi ons or habi t a t s , and 3) augm ent a t i on of natu ral or exot i c enemy popul at i ons by repeat edl y rel easi ng non-sust ai nabl e, l ab-reared (or fi el d col l ect ed) organi sm s. To dat e onl y th e fi rst , i n creasi ng fi sh habi t a t th rough OM W M , has been used i n M a ssachuset t s . B t i coul d arguabl y be cl assi fi ed as a bi ol ogi cal control agent but i t s appl i cat i on t echni que and m ode of act i on funct i oni ng as a st om ach poi son m o re closely resem b le a pesticide than a biological control agent per se . Bacillus sphaericus m a y m o re cl osel y fi t th e m odel of repeat edl y rel easi ng non-sust ai nabl e l ab-reared organi sm s as th ere i s evi d ence t o suggest th at i t

recy cl es wi th i n th e envi ronm ent
. There are i m port a nt reasons why bi ocontrol i s not m o re wi del y used agai nst m o squi t o es. Fi rst , th e d i fferen ces in b i o l o g y o f th e v a rio u s sp ecies o f m o sq u ito es m a k e it u n lik ely th at an y o n e co n tro l ag en t will o p e rate across a wi de range of speci es. Second, m o squi t o breedi ng i s wi de spread, m a ki ng i t di ffi cul t for a bi ol ogi cal control agent to find, or be placed in, all breeding areas. Third, predators such as bats and purple m a rtins, m a y eat

m o squi t o es but prefer t o eat other, l a rg er insects. Finally, there is a high cost associated with sustained releases of a biological control agent and there are not , at th is tim e, co n tro l ag en ts av aila bl e th at requi re a si ngl e, or a few, releases to becom e established. The im pacts on biological control ha ve not received mu ch attention becau se biological cont rol has not been exercised to any great degree in Massachusetts . However, one of th e pri m ary reasons Gambusia are not bei ng used in Massachusetts is the fear that they m i ght displace nativ e species of fish, thus alteri ng the natural biota, not by p r ed atio n b u t b y co m p etitio n fo r th e sam e reso u r ce. C

. Habi t a t M odi fi cat i on (Phy si cal C ontrol ) 1. Sal t M a rshes. Open M a rsh W a t e r M a nagem e nt was ori g i n al l y devel oped for New Jersey sal t m a rshes (Ferri gno 1970, Fe rri gno and Jobbi ns 1968, Ferri gno et al . 1969), th i s strat e gy basi cal l y attem p ts to o v e rco m e th e lim itatio n s o f d itch i n g b y in co r porat i ng other wat e r m a nagem e nt strat e gi es. R e servoi rs (whi ch perm anent l y hol d wat e r and sust ai n l a rvi vorous fi sh) are creat ed i n sel ect ed t i d al pool s or l a rge shal l o w pans and are connect ed vi a sm al l shal l o w di t c hes t o surroundi ng m o squi t o breedi ng depressi ons. Thi s cust om i zedapproach t o m a rsh m a nagem e nt represent s th e l east de l e t e ri ous and m o st effi ci ent non-pest i c i d al m e thod for

co n tro llin g saltm arsh m o sq u ito es. New Engl and coast a l wet l a nds have been heavi l y i m pact ed by m a n (Shi sl er 1990). However, evi d ence

co n cern i n g th e n e g a tiv e im p act o f saltm arsh d itch m a in ten a n ce activ ity is m i x e d

. Th e p r in cip a l co n cern is with di sposal of th e spoi l on th e m a rsh and th e al l e ged i nvasi on of upland plants that can occur with even slight elevation i n creases (i .e. 1-2 i n ches). OM W M effect s are apparen t l y l i m i t e d (W ol fe 1996) but al l al t e rat i ons mu st be desi gned
so th at rai s ed pat c hes of m a rsh el der and other boundary pl ant s are not creat ed. 2. Freshwat er W e t l a nds (excl u si ve of Vernal Pool s). Pal u stri ne wet l a nds, i n cl udi ng

em ergent , scrub-shrub and forest ed wet l a nds, are th e dom i n an t system in wh ich Massach u s etts fresh water p h y sical control take place. Typically, this wo rk consists of m a intaining existing d itching designed to re m ove standing water from th e wet l a nd, th ereby reduci ng m o squi t o -breedi ng habi t a t
. For m o st M C Ps, th i s t y pe of work (source reduct i on) m a kes up a l a rge percent a ge of th ei r control effort . Though reduci ng st andi ng wat e r cert a i n l y reduces

m o sq u ito b r eed in g , th ere h a s b een little research co n cern i n g th e o v e rall effects o f th ese alteratio n s o n th e m o d i fied wet l a nd. Di t c h sy st em s can becom e probl em s i n th ei r own ri ght , produci ng m o squi t o es i f l e ft unm ai nt ai ned. M o st of th ese sy st em s were never desi gned speci fi cal l y for m o squ i t o control and th ei r other, pri m ary funct i on, such as

rem ovi ng runoff from l a rge parki ng l o t s , m a y cause consi d erabl e dam a ge t o th e ecosy st em , l eavi ng th e M C P t o clean up, or at least deal with, som e one else’s m e ss. Th e m a j o rity o f d r ain a g e system s cu rren tly m a in tain ed b y MCPs were n o t in itially co n s tru c ted fo r

m o squi t o control and th e effort of M C Ps t oday i s al m o st ent i r el y restri ct ed t o rem ovi ng bl ockages t o exi s t i ng fl ows, rath er th an en larg in g o rstraig h t en in g ch an n e ls to in cr ease flow. Road sand and yard waste represent two of the

m o st com m on obstr uct i ons M C Ps are cal l e d upon t o rem ove from exi s t i ng drai nage net w orks. New devel opm ent s also can cause dram atic changes in th e sedi m e nt l o ad i n stream s, despi t e regul at i ons desi gned t o prevent such probl em s. R o ad sand, y a rd wast e and i n creased sedi m e nt l o ad from devel opm ent can al l have i m pact s on a stream that are as greater or greater than regular ditch m a intenance. Because MCPs are often involved in rem oving

m a nm ade sedi m e nt s from stream s, a sy st em under appropri a t e di t c h m a i n t e nance m a y funct i on m o re cl osel y t o a natural system than one in which m a nm ade wastes are allowed to accumu late unabated. The th ree broad cat egori e s of wet l a nds al t e rat i on are outri ght l o ss, changes i n th e abi o t i c sy st em and changes in the biotic com munity. Filli ng and/or draining wetlands to convert them to upland is a m o squito-controlp r actice th at h a s b een all b u t elim in ated in Massach u s etts. Th ere is n o in d i catio n th at MCPs are in ten tio n a lly reduci ng wet l a nd acreage i n order t o control m o squi t o es. However, th e fact th at th e wet l a nds boundary rem a i n s essent i a l l y unm oved by a m o squi t o -control al t e rat i on does not m ean that changes to the ecosystem have not occurred. C h anges i n th e abi o t i c sy st em and bi ot i c com muni t y are deepl y i n t e rt wi ned, though phy si cal control m o st

o f

ten cau ses ab io tic ch an g e s wh ich th en cause bi ot i c changes. For channel s changes i n fl ow rat e s, m i crohabi t a t s , sedi m e nt l o ad, sedi m e nt at i on, and groundwat er i n t e ract i ons can al l occur. For wet l a nds (out si de of channel s ) changes can include lost water-storage capaci t y , i n creased sedi m e nt at i on and pol l u t a nt l o ad, changes i n wat e r depth, and changes i n groundwat er hy drol ogy . W h en a stream i s al t e red t o i m prove wat e r fl ow for th e purpose of rem ovi ng st andi ng wat e r, ei th er wi th i n the stream or from adj acent wetlands, a num ber of change s m a y take place. By defin ition, im proving water flow increases runoff. This, in turn, m a y decrease the surface-water storage capacity of the wetland system and decrease th e cap ab ility o f th e wetlan d to retain lo ad (su s p e n d e d so lid s). Th is m a y in crease th e lo ad o f th e water m o v i n g th rough th e stream (B rown 1988). Increasi ng runoff i n t o a gi ven stream t e nds al so t o i n crease erosi on, whi c h further increases load (W illiam s & Feltm antle 1992). Not onl y m a y total flow be increased, but alteration tends to i n crease peak fl ow, whi c h i s associ at ed wi th reduct i ons i n faunal di versi t y (Hy n es 1972). Increased peak fl ow m a y also lead to faster d r yin g in in term itten t stream s. M a i n t e nance for th e purpose of reduci ng m o squi t o breedi ng al so i n cl udes rem ovi ng obstr uct i ons wi th i n stream s. Tree branches and fal l e n tr ees are a part i c ul arl y i m port a nt part of th e stream envi ronm ent , provi di ng food, living space, concealm e nt from predator s, protection from abiotic conditions and em ergence sites (W ard 1992). Rem o v i n g th ese o b s tru c tio n s d i m i n i sh es th e v a riab ility o f th e stream eco system
. The hyporheic zone, the interstitial sp ace between the substrate particles in a stream bed, is an im portant part of the habitat for m a ny stream species (W illiam s & Feltm antle 1992). Excessive drying can reduce the viability of th e hy porhei c zone. Sedim e ntation, both within stream beds and in wetlands into which stream s flow, is a problem because it can alter the stream bed com position, thereby altering the fauna, and can clog interstitial spaces, thereby reducing
th e hy porhei c zone and/ or reduci ng groundwat er recharge. Sedi m e nt s can al so i n crease exposure t o pol l u t a nt s as th ey provi de addi t i onal si t e s for pol l u t a nt bi ndi ng whi l e su spended, and th en carry th e pol l u t a nt s t o th e benthi cfau n a . Sed i m e n t atio n , h o w ev er, resu lts m o st o f ten fro m so u r ces o th e r th an m o sq u ito -co n tro l activ ities, an d it is th e prim ary cause of m a intenance work. W h en new channels are constructed, they are typica l l y desi gned t o change st andi ng-wat e r wet l a nds t o soi l

satu rat e d wet l a nds (New Jersey DEP 1997). Though th i s re duces m o squi t o breedi ng i t can al so adversel y affect
other organi sm s th at requi re st andi ng wa ter for periods other than peak flow. Increased drai nage al so has an effect on groundwat er. Preci pi t a t i on and i n fl ow det e rm i n e th e am ount of water initially available to a wetland for ground water recharge (Todd 1972). Increasing the am ount of water

rem oved from th e wet l a nd and/ or stream pri o r t o perc ol at i on downwards m a y decrease groundwat er recharge. W h at i s m o st needed i s a com p rehensi v e underst a ndi ng of th e tr ue ecol ogi cal cost s of phy si cal al t e rat i ons for m o squito control. This is particularly im portant because, although the environm ental effects of pesticides receive the lion’s share of concern, it is likely that the long-term effects of physical controls have a m o re profound effect on th e envi ronm ent th an does pest i c i d e use (B uchsba um 1994). Thi s m a y be especi al l y tr ue t oday wi th th e swi t c h from broad-spectrum , m o re-persi st ent pest i c i d es t o m e thoprene and B t i

. 3. Vernal Pool s. Vernal pool s form i n c ont ai ned depressi ons i n whi c h wat e r st ands for a peri od of several m onths, general l y from m i d- t o l a t e wi nt er th rough th e spri ng. W a t e r ei th er com e s i n th e form of

snow m e l t or spri ng preci pi t a t i on or can be a resul t of a ri si ng wat e r t abl e. Som e pool s dry down wi th i n t w o or th ree m onths, others m a y onl y dry when th e wat e r t abl e i s l o wer th an norm a l , resul t i ng i n a pool th at i s sem i

perm anent
. R e gardl e ss, a key feature of vernal pool s i s th at th ey undergo peri ods of dry down. Vernal pool s m a y have perm anent i n l e t s but do not have perm anent out l e t s (Kenney 1995). There are num erous obl i g at e speci es for vernal pool s, th e m o st vi si bl e of whi c h i n cl ude fai r y shri m p , th e wood frog ( Rana syl v at i c a ) and several speci es of sal a m a nder ( Ambyst oma spp.). Mosquito species such as Ae. canadensi s and Ae. excrucians al so use vernal pool s for breedi ng. From a control perspective, vernal pools are im por tant because, due to increasing protecti on, vernal pool habitat is often left undeveloped while the land adjacent to the pool is built up. As a result, m a ny new developm ents surround known breedi ng si t e s. R e gardl e ss of th e wi sdom of devel opi ng so cl ose t o vernal pool s, m o squi t o -control personnel are charged wi th control l i ng th e m o squi t o es com i ng from th e pool

. 4. R a re and Endangered Speci es. Oper at i ng under th e assum p t i on th at i t

i s rare and

en d a n g e red sp ecies wh ich are m o st lik ely to b e lo st fro m a wetlan d s system first, th en red u c tio n s in h ab itatd i v e rsity, alteratio n s fro m th e n a tu ral state, an d freq u e n t d i stu rb a n ces will all wo rk ag ain s t th ese sp ecies. C h annel i zat i on of stream s reduces di versi t y by rem ovi ng obstr uct i ons, strai ght eni ng th e channel and i n creasi ng fl ood l e vel s . W e t l a nds changed from st andi ng-wat e r t o satu rat e d-soi l regi m e s have been drast i cal l y changed from
th ei r natu ral st at e. M a i n t e nance i s ongoi ng, as i s th e di sturbance i t causes. However, t o what ext e nt does m o squi t o control contri but e t o th e th ese probl em s? Fi rst , M a ssachuset t s M C Ps do not channel i ze stream s, as th ei r cert i f i cat i on m a nual cal l s for fol l o wi ng th e exi s t i ng m eanders. Second, M C Ps work nei th er i n hi st ori cal l y undi sturbed, nor current l y undi sturbed stream s. There i s good reason t o argue that there is no specific “natural” stat e that can be assigned a ditch dug by m a n and interm ittently filled with road sand and grass cl i ppi ngs. Even wi th natu ral stream s, th e “n atural ” habi t a t i n whi c h th ey fl ow has l ong been al t e red and cont i nues t o be al t e red. The Natu ral Heri t a ge and Endangered Speci es Program (NHESP) was creat ed i n order t o conserve and prot ect those pl ant s and ani m al s not hunt ed, fi shed, tr apped or com m e rci a l l y harvest e d i n th e st at e. The program ’s hi ghest pri o ri t y i s t o i nvent ory ra re and endangered speci es and t o deve l op conservat i on pl ans th rough research,

m a nagem e nt and habi t a t prot ect i on for those speci es The NHESP al so revi ews proposed al t e rat i ons t o wet l a nds habi t a t s under th e W e t l a nds Prot ect i on Act (M .G.L. c. 131, s. 40 and regul at i ons 310 C M R10.00). NHESP has produced a seri es of est i m at ed habi t a t m a ps for rare and endangered speci es ( Massach u s etts Natu ral Heritag e Atlas ) whi c h proponent s of a gi ven al t e rat i on are required to check. Should a project fall within an estim ated habitat, NHESP w ill then determ ine if the area to be altered is actu a l wetlan d h ab itat fo r a state-listed sp ecies. Th e resu lts o f th e NHESP d e term in atio n are g i v e n to th e i nqui ri ng M C P. In Massachusetts, the species that have caused m odifi cations in m o squito control practices are the Bluespot t e d sal a m a nder ( Ambyst oma l a t e ral e ), M y st i c Val l e y am phi pod ( C r angonyx aberrans ), and banded bog

s k i mme r( Willia mso n i a lin tn eri ). In addi t i on, di t c h m a i n t e nance i n vernal pond areas has been curt ai l e d t o prot ect th is typ e o f h ab itat. Oth e r an im als fo r wh ich co n cern s have been rai s ed are th e y e l l o w-spot t e d tu rt l e and osprey

. Un d e r th e cu rren t system m o sq u ito -co n tro l m a in ten a n ce activ ities are ex em p t

fro m th e Massach u s etts W e tland Protection Act, leaving the fe deral 401 W a ter Quality Certification Act and both the Massachusetts and Federal Endangered Species Acts as a m e thod for regulating m a intenance. Unfortunately, water quality, while i m port a nt , does not address th e i ssue of changi ng habi t a t and th e presence or absence of a rare or endangeredspecies has little to do with the m e rits of a given draina ge project. Again, a m o re com p rehensive understanding of th e tru e eco lo g i cal effects o f m o sq u ito co n tro l is req u i red to b e tter d e term in e th e co st/b en efit ratio fo r d i fferen t t y pes of m o squi t o control , i n cl udi ng th ei r effect on rare and endangered speci es. Phy s i cal control by wat e r m a nagem e nt m a y i n crease predation, as in OMW M , or m a y elim inate predator and prey as when wet l a nds are drai ned t o soi l satu ra t i on. M o squi t o breedi ng mu st be thoroughl y docum ent e d before new work is done. Because di sturbances m a y displace som e species, and because predator species tend to rebound m o re slowly than their pr ey, m a intenance work should be conducted only when necessary. D. No Program Man y co m mu n ities in Massach u s etts h a v e ch o s en to fo reg o m o sq u ito co n tro l. Th ese to wn are u s u a lly outside of the enzootic EEE zone so the risk of hum an diseases transm itted by m o squitoes is viewed as practically

n il b y th ese co m mu n ities. In ad d itio n , th ey are n o t lo cated n ear salt m a rsh e s an d th eir atten d a n t p e st m o sq u ito p r o b l em s. Th e m i d

- sectio n o f Massach u s etts, wh ere m o st n o - co n tro l co m mu n ities o ccu r, also h a s a m o re ru ral charact er, l e ss wet l a nd , l o wer hum an popul at i ons, and a l o wer m ean fam i l y i n com e th an m o st east e rn areas wi th organi zed M C Ps. In addi t i on t o ri sk-benefi t consi d erat i ons, other cr i t e ri a for wei ghi ng th e control /no control opt i on are 1) the feasibility of successfully reduci ng annoyance below the hum an annoyance th reshold, and 2) the adequacy of

com munity resources for reduci ng annoyance to acceptable levels. It

i s di ffi cul t t o m easure th e i m pact of choosi ng th e no control opt i on. The exam pl e of t o wns th at have l e ft , and l a t e r rejoi n ed, m o squi t o control project s i s perhaps th e onl y avai l abl e basi s for est i m at i ng publ i c opi ni on concerni ng such i m pact . However, no docum ent a t i on of a nnoy ance l e vel s , cases of di sease, recreat i onal dol l a rs spent, etc., was ever attem p ted in th ese t o wns when th ey had m o squi t o control versus when th ey di d not

. The num ber of t o wns i n M C Ps decl i n ed i n th e l a t e ei ght y ’ s. Econom i c fact ors, not envi ronm ent a l concerns, were t h e dom i n ant reason gi ven for wi thdrawal

. Th is tren d h a s rev e rsed itself sig n i fican tly in th e last several years. The 1990 EEE problem is probably one reason, coupled with the fact th at several coastal program s tr i e d th e no-control opt i on and found m o squi t o num bers rose qui ckl y .
IV. IPM as it Relates to Mo sq u ito Co n tro l. A. Defi ni t i on of IPMAt its m o st b a sic IPM is: A system designed to reduce the negative im pact of a pest species to an acceptable level while avoiding unnecessary addi t i onal probl em s (Vi r gi ni a C ooperat i v e Ext e nsi on Servi ce 1987). For m o squi t o control i n general th e negat i v e i m pact s of m o squi t o es are reduct i on i n out door use, part i c ul arl y recreat i onal , and di sease tr ansm i ssi on. These negat i v e i m pact s are al l ongoi ng i n M a ssachuset t s . Probl em s th at have devel oped i n th e past are l o ss/ degrada t i on of val u abl e habi t a t , exposure of non-t a rget organi sm s to p e sticid es, creatio n o f n e w, so m e tim es wo rse, b r eed in g h ab itat, an d resistan ce o f m o sq u ito es to p e sticid es in u s e. Other th an exposure of non-t a rget s t o pest i c i d es (una voi dabl e) none of th ese probl em s have been docum ent e d i n M a ssachuset t s . Before an IPM program can be put in place, a strong organization mu st be in pl ace. The organization mu st be adequat e l y funded, adequat e l y tr ai ned and provi ded wi th th e m a t e ri al s t o do th e job correct l y . At a m i ni mu m expert i s e i n m o squi t o bi ol ogy , wet l a nds ecol ogy , and program adm i ni strat i on are requi red. Adequat e st affi ng and resources are onl y th e fi rst st ep s in creating an IPM program . The m a in step is in creating the analytical proce ss whereby control decisions are m a de, evalua t e d and m odi fi ed. Thi s process can be d i v i d e d in to fo u rstep s: 1 ) Su rv eillan ce an d Mo n ito rin g , 2 ) estab lish i n g Th resh o l d s fo r Actio n , 3 ) Prev en tio n an d C ontrol , and 4) Eval uat i on. 1. Surveillance and Monitoring. For m o s quitoes, adult populations are m onitored for their di rect i m pact on peopl e whereas l a rval popul at i ons are m oni t o red for th ei r pot ent i a l i m pact aft e r th ey em erge as adults. For adult populations, m onitoring is used to determine if adulticiding is require d and to identify the species of m o squi t o i n a gi ven area so th at futu re l a rval control efforts can be directed at th e appropri a t e breedi ng si t e s. Larval popul at i ons are m oni t o red t o det e rm i n e i f l a rvi c i d i ng i s requi red and/ or i f phy si cal or bi ol ogi cal control s are worki ng. The habi t a t s i n whi c h breedi ng occurs or i n whi c h th e adul t m o squi t o es are m o st num erous mu st al so be i d ent i f i e d. W e t l a nds shoul d be m apped as shoul d drai nage basi ns.

A third com ponent of m onitoring is to classify the ar ea in which control is to take place by hum an usage. Unless funding is not a constraint, the goal of surveillance and m onitoring should be to produce a site list prioritized by th e l e vel of m o squi t o breedi ng and i t s proxi m i t y t o hum ans. 2. Est abl i s hi ng Threshol ds for Act i on. The goal of IPM i s t o keep pest l e vel s bel o w th eEconom ic Injury Level (EIL). This is the level wher e the econom ic loss from pest dam a ge exceeds the cost of
control

. In m o squi t o control , th i s i s th e Hum a n Annoy ance (or Di sease) Threshol d (HAT) and represent s th e hi ghest bi t i ng densi t y (or Di sease Inci dence) th at m o st c itizen s in a co m mu n ity fin d to lerab l e. In to leran ce is usually exem plified by people m oving indoors, putting on repellent , leaving a cam pground etc.. HAT is generally
th e bi t i ng l e vel above whi c h m o st peopl e prefer t o pay t o have th e l e vel reduced th an put up wi th th e annoy ance. This level will vary from com munity to com munity and m a y be influenced by the species biting (Sjogren, 1977), the tim e of day when annoyance occurs, and the dur ation of the period when HAT is exceeded. The choi ce of control m easures t o use, and th e ext e nt t o whi c h a gi ven control m easure i s used, i s det e rm i n ed by th e pest speci es and popul at i on, th e envi ronm ent i n whi c h th e pest popul at i on i s l o cat ed, and hum an factors expressed in political and econom ic term s. Determ ining which contro l options are available and how mu ch funding will be allocated to each, c oupled with an understanding of the pest population, s hould allow action
th reshol ds t o be creat ed. 3. Prevent i on and C ontrol

. Prevent i on refers t o m a i n t a i n i ng a pest popul at i on bel o w th e act i on th reshol d for control , whereas control refers t o bri ngi ng a pest popul at i on back under th e th reshol d for
control

. Source reduct i on i s th e pri m ary prevent i on t echni que fo r m o sq u ito co n tro l in th at it d i rectly red u ces th e area i n whi c h m o squi t o es can breed. M a i n t a i n i ng wat e r fl ow th rough drai nage net w orks i s th e pri m ary freshwat e r

m o squi t o control t echni que whi l e di t c hi ng used t o be th e pri m ary prevent i on i n sal t m a rshes. Program s th at do not
stress source reduct i on cannot m a ke l ong-t e rm reduct i ons i n m o squi t o popul at i ons. Public education is a second vital com ponent of prev ention. An educated public should be m o re willing to cooperat e i n el i m i n at i ng m a n-m a de breedi ng habi t a t s , s houl d bet t e r underst a nd th e tr ade-offs bet w een th e vari ous available control techniques, and should be m o re willing to fund m o re expe nsive approaches if the expense can be just i f i e d by a bet t e r l ong-t e rm benefi t
. Co n tro l, in th e sen s e o f k illin g m o sq u ito es, is d o m in ated b y ch em ical u s e fo r ad u lt m o sq u ito co n tro l. Fo r larvae a com b ination of chem ical control and OM W M (bi o l ogi cal / phy si cal control ) i s used. Thresholds are vital to the contro l process because only through threshol ds can a rational response be m a de to unusual circum stances. A quality IPM program cannot “fail” in the strict sense becau se it has control techniques available for each step in pest populati on increase (or, in the case of a diseas e threat, each increas e in the risk of contracting the disease).4. Evaluation. Each control step is eval uated for efficacy and futu re actions m odified to im p r o v e co n tro l o rred u ce n e g a tiv e im p acts. Field ev alu a tio n will g e n e rally u s e th e sam e m o n ito rin g tech n i q u e s described above and the im portant crite ria will be changes in the m o squito population and/or envi ronm ent. Over t i m e, a st eady st at e shoul d devel op where real i s t i c th reshol ds tr i gger effect i v e responses. B. IPM fo r Mo sq u ito es as it is Cu rren tly Practiced in Massach u s etts. The strat e gy of IPM as devel oped for agri cul tu ral ecosystem s is an ecologica lly-based concept (Axtell 1979). It has y e t t o be ful l y appl i e d t o m o squi t o m a nagem e nt program s. IPM i s a strategy for m a nagi ng i n sect popul at i ons not a m e thod fo r co n tro llin g th em . It is m o re th an in teg r ated co n tro l wh ich is sim p ly th e co m b in in g o f several control m e thods. M o squi t o control has a l ong hi st ory of i n t e grat i ng di fferent control m e thods. The general feeling am ong m o st MC practitioners is that any significant larval population within flight range of residential areas will probably result in som e hum an annoyance and therefore should be controlled. No Project i n M a ssachuset t s has undert aken such an effort

.

Al though m a ny M C program s regul arl y m oni t o r adul t popul at i on l e vel s (wi th l i ght tr aps and l a ndi ng counts) they do it to evaluate larval control effectiveness and the need for adulticiding; not to determ ine when i m m e di at e l a rval control i s needed as i n th e case of agri cul tu ral IPM program s. However, l i ght tr ap count s, l a ndi ng rates and com p laint calls are used to create a general picture of th e need for m o squi t o control and project s wi th l ong-t e rm experi ence devel op l a rvi c i d i ng pl ans based on th i s hi st ori cal dat a . There i s no study t o dat e of th e cost s and benefi t s of M a ssachuset t s m o squi t o control program s. There i s good reason t o bel i e ve, even i f such studi es were done, th at th e resul t s woul d refl ect l o cal , current thought , as opposed to som e underlying “true” cost/b enefit for m o squito control. Regardless of the underlying variability of any cost / b enefi t anal y s i s , worki ng t o wards an underst a ndi ng of th e cost s and benefi t s of m o squi t o control i s desi rabl e. The fol l o wi ng i n form at i on woul d ai d i n such work: 1) Est abl i s h hum an annoy ance th reshol ds (HAT) 2) Docum e nt how hum an act i v i t y pat t e rns rel a t e t o HAT and econom i c fact ors 3) Determ ine cost/benefit analys is of control (willingness to pay) 4) Correlate HAT with a standard non-biting sam p ling m e thod (e.g. light trap) 5) Correlate densities of im m a tures w ith future levels of biting annoyance. The cost / b enefi t of vari ous control opt i ons (e.g., perm an ent vs. t e m porary control ) al so has been eval uat e d(Ofiara & Allison 1986a, 1986b) but this should not be confused with the cost/benefit of control program s. One m a jor advance al ready underway i s vastl y i m proved m a ppi ng t h rough Geographi c Inform ati on Sy st em s (GIS). GIS wetlan d s m a p p i n g can b o t haidm o sq u ito co n t ro l ag en cies in d e term in in g co n t ro l p rio rities b u t can b e u s ed by m o squi t o cont rol agenci es t o i n t e grat e t h ei r work wi t hot her l and-use agenci es (Gut he 1993). Very det ai l e d m a ps can al so be m a de when pl anni ng wat e r m anageme nt project s (Get tm an 1995). Overal l , M a ssachuset t s m o squi t o -control IPM strengths i n cl ude, strong control program s, good pretreatm e nt m onitoring, the availability of and willingness to use least-toxic m a terials and a willingness of existing
control program s t o tr y new control strat e gi es. W eaknesses i n cl ude a l ack of funds for research i n t o new strat e gi es, a l ack of funds t o i m pl em ent new strat e gi es and a l ack of basi c ecol ogi cal dat aon th e effect s of control strat e gi es i n use or being planned. A final wild card is EEE which dram atically increas es the stakes when attem p ting to determ ine the correct response. DPH has developed a m onitoring program that should bring EEE into the IPM fram e work.

V. St andards For M o squi t o C ontrol A. St andards for M oni t o ri ng and C ontrol

. Pe st i c i d e appl i cat i ons i n an IPM program requi re

m onitoring insect populations and com p ari ng data with pre-established threshol ds for treatm e nt. In addition, posttr eat m e nt eval uat i on i s requi red t o ensu re the treatm e nt worked as planned a nd di d not have uni nt ended si de-effect s. 1. Larval Popul at i ons: The pri m ary t echni que for l a rval popul at i on count s i s th e di p count . It i s hard t o st andardi ze di ppi ng t echni que but , for th e purposes of th i s docum ent , i t i s assum e d th at di ps are t a ken i n undi sturbed pool s (the fi el d person i s aware th at di sturbi ng th e wat e r and/ or cast i ng a shadow over th e water will cause m o squitoes to dive, thereby lowering counts) known by the fi eld personnel to be typical of the breeding area being m onitored. For large-scale work, dipping will be done at perm anent, m a rked (or easily located) dip stations. For sm all sites such as drainage basins and woodland pools, dips will be taken at random throughout the site. Up to twenty dips per site will be taken unl ess the count for treatm e nt a nd/or water m a nagem e nt is exceeded with a sm aller num ber of dips. Specifics fo r various types of work are given in Table 2.

Tabl e 2. Speci fi cs for m oni t o ri ng l a rval (& pupal ) popul at i ons of m o squi t o es for det e rm i n i ng control

. No Treatm e n t Pesticid e W a ter m a n a g e m e n t #Sites fo r larg e-scale wo rk Appl i cat i on Sal t M a rsh <1 per 10 di ps 1+ per 10 di ps 5+ per di p a 1 di p st at i on per 250 acresFreshwater Ground <1 per 5 di ps 1+ per 5 di ps Vari abl e Not appl i cabl e Aeri al <1 per 10 di ps 1+ per 10 di ps Not appl i cabl e 1 di p st at i on per 250 acres

a Num e rous addi t i onal fact ors go i n t o det e rm i n i ng wat e r m a nagem e nt opt i ons for OM W M

. Project s have an obl i g at i on t o ensure th at al l al t e ra t i ons funct i on as i n t e nded wi thout adverse effect s on th e

en v i ro n m en t. Po st-alteratio n wo rk fo r water m a n a g e m e n t will also m o n ito r v e g e tativ e re-g ro wth , ch an g e s in fau n a and not es on whether or not th e hy drol ogy of th e si t e i s as i n t e nded. W h en project s have hi st ori cal dat ath at est abl i s hes a pat t e rn of breedi ng at a gi ven si t e , th ey m a y conduct pre-tr eat m e nt work. 2. Adult Populations. No adulticiding programwill be conducted on a routine, preschedul ed basi s (i .e. once per week, regardl e ss).

a. Mo n ito rin g fo r Ad u lticid in g Tab l e 3

. Ad u lt m o sq u ito m o n ito rin g tech n i q u e s an d th resh o l d s fo r ad u lticid in g . Mo n ito rin g Mech an ism Rate to trig g e r ad u lticid in g Light traps Hum a n-biting m o squ ito counts exceed five per night Landing counts Landi ng count rates exceed one per m i nute Com p laint calls W h en com p laint ca lls exceed two per geographical area (th i s area will v a ry b u t assu m e ap p r o x i m a tely o n e sq u a re m ile) Projects should increase their efforts to understand th e im pact of adulticiding on m o squitoes. Projects should cross-reference com p laint calls with adulticide applications and reco rd the num ber of calls com i ng in the week before an appl i cat i on and i n th e fol l o wi ng week (thi s work m a y be done duri ng th e wi nt er for th e previ ous season). In addi t i on, project s shoul d conduct before and af t e r l a ndi ng count s and/ or l i ght -trap count s for t e n percent of their adulticide applications. La nding counts should be taken within 48 hours pre- and post-application at the

sam e l o cat i on both t i m es. Li ght tr ap sam p l e s shoul d be fro m th e sam e tr ap and for th e sam e t i m e peri od before and aft e r tr eat m e nt . W h ere possi bl e, non-tr eat ed areas si m i l a r t o th e tr eat ed area shoul d be checked t o det e rm i n e popul at i on tr ends out si de th e spray zone. B

. St andards for Phy s i cal C ontrol

. Al t e ri ng or el i m i n at i ng m o squi t o breedi ng si t e s range from proper di sposal of t i r es th rough anal y z i ng drai nage sy st em s t o creat i ng ent i r e new open m a rsh wat e r m a nagem e nt system s. Ph ysical Co n tro l refers sp ecifically to alteratio n s to b r eed in g h ab itat to p r ev en t m o sq u ito es fro m m a tu rin gt o adul thood. Phy s i cal C ontrol i s di vi ded further i n t o th ree t y pes: So u r ce Elim in atio n : Co m p letely elim in atin g th e b r eed in g site not just th e m o squi t o breedi ng. Source el i m i n at i on i s general l y l i m i t e d t o breedi ng habi t a t s creat ed by hum ans i n non-wet l a nd areas. Source M a i n t e nance: M a i n t a i n i ng pot ent i a l breedi ng sources i n such a way th at m o squi t o es cannot becom e a probl em . So u r ce Red u c tio n : Red u c in g th e ab ility o f an area to b r eed m o sq u ito es. It d i ffers fro m so u r ce m a in ten a n ce in th at th e ex istin g h ab itat is b r eed in g m o sq u ito es wh ereas, if a m a in ten a n ce p r o g r am i s runni ng as desi gned, m o squi t o breedi ng shoul d not occur. Once a source reduct i on project i s co m p leted , it will, in m o st cases, req u i re at least so m e so u r ce m a in ten a n ce in o r d e r n o t to retu rn to bei ng a m o squi t o -breedi ng habi t a t
. The Massachusetts DEP has recently (March 1997) issued a Storm w ater Policy Handbook and a St orm w at er Techni cal Handbook. These provi de gui del i n es for st orm w at er m a nagem e nt and shoul d be used t o det e rm i n e appropri a t e control m easures th at M C Ps shoul d i m pl em ent
. C u rrent l y , th e pri m ary causes for concern regardi ng phy si cal control i s th at th er e aren’t always adequate records of the reasons for a specific m a intenance project nor are there also adequate site pl ans by whi c h i t can be det e rm i n ed that increases in ditch cross-section and/ or l e ngth are not occurri ng. C. Standards for Chem ical Control. Pro j ects mu st co m p ly with reg u l atio n s fo r aerial ap p licatio n s o f p e sticid es. For truck-m ounted adulticiding, projects should notif y the public through the pr int m e dia, between March 1st and May 1st of each year, as to the areas that m a y be tr eated, the pesticide to be used and a num ber to contact for

m o re i n form at i on or t o request excl usi on from tr eat m e nt
. As education is a prim ary aspect of an IPM program , project s are encouraged t o devel op educat i onal fl y e rs covering such aspects of their work as pesticide use, wat e r m a nagem e nt , and propert y - owner m o squi t o control

. Fl y e rs m a y ei th er be devel oped i n -house or be obt ai ned from th e st at e or other agenci es. Asi d e from th e pest i c i d e applicator recertification requirem e nt s, program s are urged to provide oppor tunities for staff to increase their knowl e dge about m o squi t o es, wet l a nd, and m o squi t o control

. D. Standard Operating Pro cedures during EEE problem

. W h en surveillance data points to increasing leve ls of EEE risk, DPH notifies the SRMCB and regional MCP superintendents. The EEE Surveillance Program inform s MCP superintendents of is olations of EEE in their districts and the districts, in turn, provide feedback to DPH regardi ng population and life stag e indices for critical

m o sq u ito sp ecies. At certain d e fin e d in terim lev e ls o f risk as o u tlin ed in th e “Vecto rCo n tro l Plan ,” MCPs m a y b easked to increase their ground control larvicide and/or a dulticide applications in re sponse to increased EEE virus
act i v i t y . The SR M C B i s responsi b l e for contract i ng wi th appropri a t e m o squi t o control appl i cat ors i n th e event th at aerial EEE vector control is recom m e nded by DPH.

VI. R ecom m e ndat i ons A. Legal , Organi zat i onal and Fi scal As pect s of M a ssachuset t s M o squi t o C ontrol The organi zat i onal structure and fundi ng for M a ssachuse t t s m o squi t o control program s, be th ey regi onal or t o wn based, rest s predom i n at el y at th e l e vel of t o wn gove rnm e nt , al though th e st at e l e gi sl at i v e bodi es have a di rect i n fl uences over ei ght of th e ni ne M C Ps’ annual budget s (onl y East M i ddl esex i s not so affect ed). In contrast , th e

o v e rseer o f m o sq u ito -co n tro l activ ity in Massach u s etts is th e State Reclam atio n an d Mo sq u ito Co n tro l Bo ard

. Th is i s a l oose arrangem e nt for del i v eri ng a publ i c servi ce th at i s best appl i e d at a regi onal l e vel

. Lack of control effort i n one t o wn can great l y effect th e effi ci ency of control effort s i n nei ghbori ng t o wns. En ab lin g leg i slatio n h a s b een written in a p a tch w o r k m a n n e r so th at th ere is cu rren tly little co n s isten c y from project t o project . For exam pl e, t o wns i n B a rnst abl e C ount y (and form erl y i n B e rkshi r e) are al l m e m b ers of
th ei r respect i v e regi onal M C project and no i ndi vi dual com muni t y m a y wi thdraw from th e program wi thout changi ng th e l e gi sl at i on as di d C h ap. 119 of th e Act s of 1982 i n th e case of B e rkshi r e C ount y . Thi s provi des an assurance of fiscal and organizational st ability that is lacking in other program s. For exam ple, the Essex County and C e ntral M a ssachuset t s project s both went th rough c onsi d erabl e upheaval s i n m e m b ershi p bet w een 1988 and 1993. Fortunately, the other projects have rem a ined rem a rkably stable ove r the past decade. Maintaining and im proving stability, both in m e m b ership and funding, is a desirable goal. Thi s uncert a i n fi scal pi cture i s further com pounded by th e fact th at al l M C project s i n M a ssachuset t s are seri ousl y under-funded. In other st at es, wi th progressi ve M C program s, th e per capitaexpendi tu re vari es from $2 upward. In Massachusetts, it averages about $0.50 (based on $2 per household of 4 peopl e). In addition, m a ny other st at es provi de suppl em ent a l st at e funds t o encourag e non-chem i cal control effort s and for support i v e research and educational activities. No such state support exists in Massachusetts. W h en supplem ental state support has

com e , it has been for chem ical adultic iding in the wake of EEE threats. To a l a rge ext e nt , fundi ng di ct at es th e control approaches th at can be pursued. IPM , source reduct i on, 1arval control , and adul t control represent th e four m a jor opt i ons i n th ei r order of decreasi ng cost and effi ci ency .Thus, poorl y funded program s are forced i n t o m o re rel i a n ce on l e ss effi ci ent and m o re controversi a l t echni ques. Larger, bet t e r-funded, and st abl e regi onal project s can i nvest i n bet t e r pai d and tr ai ned em pl oy ees, bet t e r surveillance and public education program s, and expensiv e equipm ent such as helicopters which can broaden the opt i ons for safer and m o re effi ci ent l a rval control (e.g., granul ar l a rvi c i d i ng wi th B t i and m e thoprene). Giv e n th e fact th at sev e ral d i fferen t state ag en cies are co n cern e d with m o sq u ito co n tro l activ ities, th e current system of interagency res ponsibility for overseeing MC activities (i.e ., State Reclam ation and Mosquito C ontrol B o ard represent i ng 3 di fferent st ate agencies) is perhaps the best co m p rom i se arrangem e nt . On th e other hand, the level of general support services that projects a nd towns receive from this Boar d seem s to be inadequate. R ecom m e ndat i ons That new and com p rehensi v e enabl i ng l e gi sl at i on be draft e d, revi ewed, appropri a t e l y revi sed, and passed into law, which will bring all MC c ontrol activity in Massachusetts under th e sam e organizational, fiscal and operat i onal gui del i n es. Thi s l e gi sl at i on shoul d provi de for th e fol l o wi ng: 1. The St at e R ecl am at i on and M o squi t o C ontrol shoul d have th e fol l o wi ng personnel :

a. An Execut i v e Di rect or @ approxi m a t e l y $45,000 per y ear b. An Engi neer @ approxi m a t e l y $35,000 per y ear

c. An Ent o m o l ogi st @ approxi m a t e l y $35,000 per y ear Not onl y woul d th i s st affi ng perm i t th e st at e t o conduct research i n t o m o squi t o control , i t woul d provide a team for rapid response to EEE thr eats in com munities that are not m e m b ers of
est abl i s hed M C Ps. Thi s st aff woul d al so provi de servi ces such as i n corporat i ng DEP st orm w at er

m a nagem e nt gui del i n es i n t o M a ssachuset t s M C P Upl a nd W a t e r m a nagem e nt operat i onal procedures. 2. An operat i ons budget , above and bey ond th e norm a l needs of th e SR C M B , for research and devel opm ent
. A m i ni mu m of $50,000 per y ear i s suggest ed. 3. A com p etitive grant fund (funded by the state, adm i nistered by the Execu tive Director of SRMCB and advi sed by an ad hoc panel of out si de expe rt s) t o support IPM rel a t e d research and del i v ery program s wi th i n th e st at e m o squi t o control ent e rpri se. Thi s shoul d provi de support for studi es such as: cost / b enefi t anal y s i s of m o squi t o -control program s; devel opm ent of hum an annoy ance th reshol ds (HAT); i m proved m e thods for m oni t o ri ng and predi c t i ng m o squi t o popul at i on l e vel s ;devel opm ent , eval uat i on, and i m pl em ent a t i on o£ new, non-chem i cal m o squi t o m a nagem e nt t echni ques (e.g., open m a rsh m a nagem e nt and bi ol ogi cal control ) ; m a nagem e nt of pest i c i d e resistance, drift and other use exposures; im p act of MC activities on surface and ground water, and on non-t a rget organi sm s; and th e bi ol ogy and rol e of sel ect ed speci es i n di sease tr ansm i ssi on. 4. The SRMCB should establish a com m ittee to work with their staff to de velop best m a nagem e nt p r actices (BMPs) fo r all asp ects o f m o sq u ito co n tro l, th e resu lts o f th eir wo rk b e in g u s ed to update the GEIR on a regular basis. The co m m ittee should include four m o squito-control superi nt endent s, four represent a t i v es of envi ronm en tal agencies (federal, state or private) and one
at -l arge m e m b er t o serve as chai rperson. Thei r fi rst order of busi n ess shoul d be t o devel op a set of B M Ps for freshwat e r drai nage m a i n t e nan ce for m o squi t o control

. These B M Ps shoul d
est abl i s h stri ct defi ni t i ons for project s i n whi c h th e m o squi t o control exem pt i on from th e W e t l a nds Prot ect i on Act m a y be appl i e d. 5. M C Ps mu st have th e authori t y t o deny request s for m a i n t e nance work th at does not have a

m o squito-control com ponent. Because these reque sts are often m a de by the sam e persons or

municipalities which provide fundi ng to the MCPs, the SRMCB mu st be willing to act as an appeal s board, t o whi c h a request for work m a y be sen t b y an ap p lican t in th e ev en t th e m o sq u ito
control program deni es th e request
. 6

. Lim it m o sq u ito co n tro l activ ity to reg i o n a lly based regi onal m o squi t o control program s whi c h can be organi zed by th e appropri a t e publ i c vot e. The SR M C B shoul d organi ze th e regi onal based

m o squi t o control program s and appoi nt project or di stri ct com m i ssi oners. The SR M C B shoul d select Com m i ssioners from candida tes proposed by authorized Bo ards/individuals from the cities and t o wns of th e m o squi t o control project s or di stri ct s. 7. A fl exi b l e and appropri a t e sy st em of t a x assessm ent whi c h al l o ws for budget s th at are adequat e t o provi de for th e i m pl em ent a t i on of th e m o st cont em porary and l east ri sky strat e gi es for control l i ng

m o sq u ito es. 8. A l e gal sy st em whereby al l m a jor zoni ng and constr uct i on pl ans i n th e C o m m onweal th are revi ewed by th e execut i v e di rect or of SR M C B and th e appropri a t e count y M C di rect or for th ei r pot ent i a l i m pact on m o squi t o popul at i ons and hum an heal th

.B

. Operat i onal Aspect s of M a ssachuset t s M o squi t o C ontrol Operat i onal program s i n M a ssachuset t s coul d l e gal l y be usi ng chem i cal s (approved by EPA and th e Massachusetts Pesticide Board) that are significantly m o re hazardous than those used in current practice. This suggests that knowledge and sensitivity fo r the environm ent and hum an safety ar e generally being considered by the exi s t i ng control program s. As al ready i ndi cat ed, fundi ng l e vel s sel dom al l o w project s t o fol l o w th e opt i mum operat i onal course. Despi t e th ese fi scal constr ai nt s, proj ect s have si gni fi cant l y changed th ei r operat i onal m e thods i n recent years toward m o re source reduction work such as the Open Marsh W a ter Managem e nt projects in Essex, Norfol k and Pl y m outh C ount i e s. M o st project s al so use m o re sel ect i v e and envi ronm ent a l l y com p at i b l e l a rvi c i d es such as B t i and m e thoprene. The operat i onal recom m e ndat i ons th at fol l o w are pr edi cat ed on addi t i onal and adequat e fundi ng bei ng available for im plem entation. R ecom m e ndat i ons 1. Al l M C Project s shoul d bui l d th ei r program s around th e IPM strat e gy of keepi ng hum an annoy ance bel o w th reshol d l e vel s as gi ven i n th e St andards of th i s GEIR

. 2. C ontrol m e thodol ogy shoul d be source reduct i on whenever possi bl e and l a rvi c i d al control when i t is not. Projects should work closely with th e DEP water quality certification program and the Natu ral Heri t a ge Endangered Speci es Program t o m i ni m i ze negat i v e i m pact s of source reduct i on t o wet l a nd habi t a t and/ or rare or endangere d species. The m o st target-selective and envi ronm ent a l l y com p at i b l e l a rvi c i d es (e.g., B t i , m e thoprene) shoul d be used whenever possi bl e regardl e ss of cost consi d erat i ons. 3. Sal t m arsh m o squi t o control effort s shoul d em phasi ze OM W M . Al l OM W M proposal s shoul d in clu d e p l an s fo r fillin g m a n y o f th e o l d g r id d itch e s in Massach u s etts salt m a rsh e s wh ich d o n o t funct i on i n a product i v e way and whi c h mu st regul arl y be cl eaned i n order t o prevent breedi ng i n th e d itch e s th em selv es. Th is will g r ad u a lly elim in ate th e co n tro v e rsy o v e r th e co n tin u i n g n eed to clean these ditches and the problem of what to d o with th e resu ltin g sp o il th at is created

. 4. Docum e nt l o cat i on, l e ngth, and cross-sect i on(s) of al l drai nage sy st em s m a i n t a i n ed by th e project and have th at i n form at i on avai l abl e i n an easi l y underst ood form at for publ i c i n spect i on.Ex em p tio n fro m th e p e rm ittin g p r o cess ex ten t s o n l y to th o s e d r ain a g e system s fo r wh ich ad eq u a te historical records of m a in ten a n ce wo rk ex ist. 5. The SR M C B shoul d creat e a l i s t of pest i c i d es approved for m o squi t o control i n M a ssachuset t s . Adulticides should be from Categories III and IV and larvicides should be from Category IV. 6. Adulticiding should only be carried out in em ergency situations involving disease threats or pest densities which consistently exceedthe hum an annoyance threshold. 7. For large-scale adulticiding, only ULV-cold fogging should be used. For spot treatm e nt around recreation areas or other areas where public even t s are t o be hel d , port abl e m i st bl owers usi ng perm ethri n as a resi dual pest i c i d e can be used. 8. Aeri al appl i cat i ons shoul d be restri ct ed t o gra nul ar formul at i ons i n areas where dri f t coul d be a si gni fi cant probl em . Som e t i m es som e dri f t i s de sirable so as to reduce the chance of gaps bet w een appl i cat i on swathes. In such cases a l i qui d formul at i on m a y be a bet t e r choi ce. At th i s t i m e l i qui d formul at i ons are al so si gni fi cant l y cheaper, m a ki ng l a rger appl i cat i ons, and m o re effectiv e co n tro l, easier. In creased u s e o f h e lico p t ers fo r aerial larv icid in g in co o r d i n a tio n with
th e use of dri f t

- suppressi on agent s and t echnol ogi es shoul d be encouraged (part i c ul arl y for enhanced larval control in in accessible habitats such as salt m a rshes, wooded swam ps, vernal pool s, et c.). 9. Project s shoul d fi l e a post

- tr eat m e nt report for aeri a l appl i cat i ons wi th th e Pest i c i d e B u reau whi c h gives location and acreage actually treated. The pre-application form s do not always accurately represent what actual l y happened. 10. Chem ical-use reporting needs to be m onitored to ensure uniform ity and accuracy in reporting. Previ ous report s cont ai ned such probl em s as no uni t s are gi ven on th e 1993 th rough 1995 C a pe Cod report for Bactim os (BTI), tw o di fferent EPA regi strat i on num be rs for B act i m os are gi ven i n th e 1993 C a pe C od and C e ntral M a ssachuset t s M C Ps report s , and bri quet s are vari ousl y report e d i n t e rm s of num ber of bri quet s , pounds of bri quet s or pounds of act i v e i ngredi e nt . The Pest i c i d e Bureau should insist that yearly chem ical-use reports be fille d out according to standardized procedures. R e port s shoul d be checked as th ey com e i n t o ensure th at st andardi zed report i ng procedures are followed.11. Al l pest i c i d e st orage areas shoul d be equi pped w i th sm oke, fi re and securi t y sy st em s. A st andard procedure shoul d be devel oped for th e di sposal of al l i n sect i c i d al m a t e ri al s used i n M a ssachuset t s for m o squi t o control

. The St at e Pest i c i d e B o ard shoul d encourage m a nufacturers of such product s t o m a rket reusabl e cont ai ners. A st andard pr ocedure shoul d be devel oped for th e cl ean-up of accidental spills of insecticides. Proper use of absorbent m a terials and the disposal of such

m a terials are necessary. Proper attire during formul ation and application of insecticides should be

m a de m a ndat o ry for al l i ndi vi dual s i nvol ved i n th ese processes.
C. Research Needs There i s a need i n th e m o squi t o control process i n M a ssachuset t s for a strong, operat i onal l y focused, research effort i n freshwat e r wet l a nds, excl usi v e of chem i cal appl i cat i on t echni ques. Thi s i s not t o condem n current research efforts, for we know m o re about EEE m o squitoes than ever before, have im proved saltm arsh m o squito
control dram at i cal l y , and have m a de i m provem e nt s i n bot h chem i cal s used and m e thods of chem i cal use over th e past decade. But there is a need fo r research to assess the environm ental im pacts and efficacy of the current MCP p r o g r am s relativ e to th e fresh water en v i ro n m en t. Addi t i onal research on t opi cs such as l ong-t e rm effect s of OM W M , econom i cal l y vi abl e control of Cq

. pert urbans , and m o squi t o control i n endangered speci es h ab itats also req u i re atten tio n . R ecom m e ndat i ons 1. For wat e r m a nagem e nt pract i ces, m oni t o r i m pact s on ani m al s on a case-by -case basi s, dependi ng on th e si t e and est abl i s h veget a t i on tr ansect s t o docum ent changes i n wet l a nd veget a t i on. 2. Devel op a uni fi ed dat abase th at docum en t s m o squi t o popul at i ons on an ongoi ng basi s from regul ar m oni t o ri ng si t e s. Est abl i s h st at e st andards for m oni t o ri ng m o squi t o es and provi de tr ai ni ng t o m o squi t o control project st aff i n dat acol l ect i on and m a nagem e nt
. 3. C onduct com p arat i v e studi es wi th di fferent m a na gem e nt approaches (e.g. pest i c i d e appl i cat i ons vs. wat e r m a nagem e nt ). 4. Devel op a Geographi c Inform at i on Sy st em (GIS) wi th known breedi ng si t e s and areas of h i sto r ical water m a n a g e m e n t activ ities. 5. Qual i f y si t e s on th e basi s of need for control , based on breedi ng (pot ent i a l or actual ) , m o squi t osp ecies, p r o x i m ity to h u m an activ ity, lev e l an d typ e of hum an act i v i t y , and t y pe of wet l a nd habi t a t affected. 6. C r eat e an ongoi ng research part nershi p wi th NHE SP t o docum ent wet l a nd t y pes, et c.. M o squi t o C ontrol Project s have knowl e dge and expert i s e a bout wet l a nds th at coul d be i nval u abl e t o NHESP.Literatu re Cited Axt e l l , R

. C

. Pri n ci pl es of i n t e grat ed pest m a nagem e nt (IPM ) i n rel a t i on t o M o squi t o C ontrol

. M o sq. News 39,710 (1979). B r own, R

. G. Effect s of wet l a nd channel i zat i on on runoff and l o adi ng. W e t l a nds 8,123-133 (1988). B u chsbaum , R

. C o ast a l m a rsh m a nagem e nt . i n Appl i e d wet l a nds sci e nce and t echnol ogy , D.M

. Kent (Ed.) pp. 331- 361. Lewi s Publ i s hers, B o ca R a t on, Fl ori d a (1994). Ferri gno, F. Ecol ogy of m a rsh and coast a l i m poundm ent s . Job Progress R p t
. N.J. Di v. Fi sh, Gam e & Shel l Fi sheri e s. Proj. No. W

- 34-R-16. Job No. II-A, 19pp. (1970). Ferri gno, F. and D.M

. Jobbi ns. Open m a rsh m a nagem e nt . Proc. N.J. M o sq. Ext e rm . Assoc. 55,104 (1968). Ferri gno, F., L.G. M acNam ara and D.M

. Jobbi ns. Ecol ogi cal approaches for i m proved m a nagem e nt of coast a l m eadowl a nds. Proc. N.J. M o sq. Ext e rm . Assoc. 56,188 (1969). Get t m an, A.D. M a ppi ng B l ock Isl a nd sal t m a rshes for OM W M conversi on. Proc. 41st Ann. M eet i ng of th e Northeast e rn M o sq. C ontr. Assoc. 24-25 (1995). Guth e, W

. G. GIS: a new t ool for m o squi t o control

. W i ng B eat s 4(1),4-6 (1993). Hy nes, H.B

. N. The ecol ogy of runni ng wat e rs. Uni v ersi t y of Toront o Press, Toront o, C a nada (1972). Kenny , L.P. W i cked bug puddl es; a gui de t o th e study and cert i f i cat i on of vernal pool s. Vernal Pool Associ at i on and EPA. U. S. Governm e nt Pri n t i ng Offi ce (1995). New Jersey DEP. B e st m a nagem e nt pract i ces for m o squi t o control and freshwat e r wet l a nds m a nagem e nt . Offi ce of M o squi t o C ontrol C oordi nat i on, New Jersey Depart m e nt of Envi ronm ent a l Prot ect i on. Trent on, NJ (1997). Ofiara, D.D. and J.R. Allison. On assessing the benefits of public m o squito control practices. J. Am . Mosq. Contr. Assoc. 2,280 (1986a). Portnoy, J.W

. Oxygen Depletion, Stream Clearance and Alewife Mortality in the Herring River, Sum m e r 1984. Nat i onal Park Servi ce R e port (1984a). Port noy , J.W

. Herri ng R i ver M o squi t o Survey s, 1984. Nat i onal Park Servi ce R e port (1984b). Sh isler, J.K. Creatio n an d resto r atio n o f co astal wetlan d s o f th e n o r th eastern Un ited States. in , W e tlan d Creatio n and R e st orat i on J.A. Kusl er and M

. E. Kentul a, (E ds). pp. 143-163. Isl a nd Press, W a shi ngt on, DC . 1990 Sj o g r en , R.D. Metro p o litan Mo sq u ito Co n tro l District Fi n a l En v i ro n m en tal Im p act Statem en t: Op tio n s fo r Co n tro l t o th e y ear 2000. St . Paul , M N , 464 pp. (1977). SPRP. An assessm ent of non-target effects of the m o squ ito larvicides, Bti and m e thoprene, in m e tropolitan area wet l a nds. Sci e nt i f i c Peer revi ew Panel , St . Paul , M i nnesot a(1996). Todd, D.K. Groundwater Hydrology, sec ond edition. John W iley & Sons, NY (1980). Vi rgi n i aC ooperat i v e Ext e nsi on Servi ce. The nat i onal eval uat i on of ext e nsi on’s i n t e grat ed pest m a nagem e nt (IPM ) program s. Vi rgi n i aC ooperat i v e Ext e nsi on Servi ce 123pp. W a rd, J.V. Aquat i c i n sect ecol ogy 1. B i ol ogy and habi t a t
. John W i l e y & Sons, NY (1992). W illiam s , D.D. and B.L. Feltm ate. Aquatic Insects. CAB International, W a llingford, England. (1992). W o l f e, R

. J. Effect s of open m a rsh wat e r m a nagem e nt on se lected tidal m a rsh resources: a review. J. Am er. Mosq. C ontr. Assoc. 12,701-712 (1996).II. INTRODUCTION

A Gen e ric En v i ro n m en tal Im p act Rep o r t (GEIR), co v e rin g m o sq u ito co n tro l activ ities with in th e State of M a ssachuset t s , was m a ndat e d under th e provi si on of M a ssachuset t s General Laws C h apt e r 30A Sect i on 61 by
th e M a ssachuset t s Envi ronm ent a l Pol i c y Act (M EPA) R e gul at i on 301 C M R10.32(5)(b) adopt ed on January 25, 1979. The St at e R ecl am at i on and M o squi t o C ontrol B o ard (SR M C B ) , th e st at e agency th at oversees al l l o cal and regi onal m o squi t o control program s i n M a ssachuset t s , adm i ni st ers th e GEIR . The SR M C B consi s t s of one representative each from the Departm e nts of Environm enta l Managem e nt, Environm enta l Protection, and Food and Ag ricu ltu re. Th e latter p r esen tly serv es as the Chairm an of the Board. A speci al com m i t t ee desi gnat e d as th e C i t i zen' s Advi sory C o m m i t t ee (C AC ) was est abl i s hed under M E PA R e gul at i on 301 C M R10.10(3) t o assi st th e SR M C B and th e M E PA offi ce i n devel opi ng a scope of what shoul d be i n cl uded i n th e GEIR . Fol l o wi ng th e com m i t t ee' s preparat i on of th e GEIR scope and SR M C B approval of th i s docum ent, potential GEIR contractors were invited to subm it proposals in 1985. A subcom m ittee of the CAC was appoi nt ed t o screen GEIRproposal s and m a ke recom m e ndat i ons on th e awardi ng of th e contract . A contract agreem ent with the Univ ersity of Massachusetts (Dr. J. D. Edm a n) was signed in Septem ber of 1985, and the initial Draft GEIR was prepared. The CAC received com m e nts on the initial Draft GEIRbut no action was taken on the com m e nts nor was a Fi nal GEIRpubl i s hed. In 1995 th i s si tu at i on was brought t o th e at t e nt i on of th e Execut i v e Offi ce of Envi ronm ent a l Affairs an d th e SRMCB was in stru cted to co m p lete th e GEIR. Du e to th e su b s tan tial tim e lag b e tween th e o r ig in al Draft GEIR and the renewal of the process, a Notice of Project C h ange was fi l e d wi th th e M a ssachuset t s Envi ronm ent a l Pol i c y Act Uni t i n Jul y , and th e revi sed Scope (Sect i on I above) was approved Sept em ber 23rd of
th e sam e y ear. M r . George C h ri st i e , a pri v at e m o squi t o -control consul t a nt , was hi red by th e SR M C B com m i t t ee t o rewrite th e GEIR to co n f o r m with th e n e w sco p e . Thi s GEIRserves fi ve purposes: 1

. It p r o v i d e s a h i sto r ic su m m a ry o f all p u b lic activ ities in Massach u s etts related to m o sq u ito co n tro l, i n cl udi ng a account of how m o squi t o control i n M a ssachuset t s has rapi dl y evol ved over th e past ten years. 2. It descri bes and quant i f i e s M a ssachuset t s m o squito problem s and assesses the effectiveness ofpast and current control program s. 3. It assesses th e real and pot ent i a l envi ronm ent a l i m pact s of past and current control pract i ces and descri bes and eval uat e s al t e rnat i v e strat e gi es. 4. It gives an IPM fram e work for m o squito c ontrol i n M a ssachuset t s and provi des a seri es of operat i onal st andards for m o squi t o control pract i ces. 5

. It m a k e s reco m m e n d a tio n s relativ e to th e fu tu re organi zat i on and pract i ce of m o squi t o control i n Massach u s etts. Th e reco m m e n d a tio n s were fo rm ed in co llab o r atio n with th e CAC an d th e SRM CB and were based on a joi n t revi ew of th e background i n form at i on sum m a ri zed Sect i ons III th rough VII of th i s report
.III. HISTORY AND CURRENT ORGANIZATION AND PRACTICE OF MOSQUITO CONTROL IN MASSACHUSETTS

A. Legi sl at i on and R e gul at i on 1. Overvi ew Th ere are fo u rb a sic leg i slativ e Acts wh ich reg u l ate m o sq u ito co n tro l activ ities in Massach u s etts. Often associated with each of these Acts ar e regulations (or CMR), which are devel oped by the state agency charged with adm i ni st eri ng th e provi si ons of th e l e gi sl at i v e act s. Thes e serve as the rules or polic y u s ed in th e d a y-to -d ay enforcem ent of the Acts. The fi rst Act of m a jor i m port a nce i s C h apt e r 252 of th e M a ssachuset t s General Laws (M GL), whi c h
est abl i s hes th e St at e R ecl am at i on and M o squi t o C ontrol B o ard (SR C M B ) and procedures for creat i ng l o cal control project s. As now am ended, 252 i n cl udes th e i m port a nt earl i e r provi si ons of C h apt e rs 199 and 699 of th e Act s of 1960. The word i m provem e nt (o f wetlan d s ) as freq u e n tly u s ed in th e n a rrativ e fo r th is Act is m i slead in g . M odi fi cat i on or al t e rat i on woul d have been a m o re appropr i a t e and object i v e t e rm t o descri be wet l a nd drai nage and filling activities. Although the word “im p rove m e nt” will be used in this report, in order to m a intain continuity with the Act, the reader should be aware that “m odifi cation” would be a m o re accurate description. The second Act is the W e tlands Protection Act (Chapter 131 of MGL) which regulates activities in the aquat i c and bracki s h habi t a t s where m o st m o squi t o es breed . However, organi zed m o squi t o control i s general l y

exem pt

from th e provi si ons of th i s St at e Law. Hence, th e Federal W e t l a nds Prot ect i on Act as adm i ni st ered by th e U. S. Co rp s o f En g i n eers, is th e p r in cip a l reg u l atin g m ech an ism fo r m o sq u ito -co n tro l alteratio n s in wetlan d s . R e gardl e ss of th e general exem pt i on, m o squi t o control i s not exem pt from checking for the presence of rare and endangered speci es th rough th e Massach u s etts Natu ral Heritag e Atlas , wh ich lists estim ated h ab itat m a p s fo r all rare and endangered speci es as devel oped by th e Natu ral Heri t a ge Endangered Speci es Program (NHESP). NHESP al so overseei ng vernal pool cert i f i cat i on, not by act i v el y cert i f y i ng pool s i t s el f, but by cert i f y i ng pool s brought t o i t s at t e nt i on by i ndi vi dual s or organi zat i ons such as th e Vernal Pool Associ at i on. The th i r d Act whi c h i n fl uences m o squi t o control i n th e Endangered Speci es Act (C hapt er 131A of M G L) whi c h prohi bi t s th e “t aki ng” of rare and endangered speci es. It al so prot ect s “si gni fi cant habi t a t s ,’ requi ri ng a perm i t request for any work done i n such areas.Th e fo u r th State Act o f im p o r tan ce to m o sq u ito co n tro l activ ities is th e Pesticid e Co n tro l Act (Ch a p t er 132B of MGL) which regulates pesticide use by m o squito control practitioners. Except as already m e ntioned, Federal Laws do not general l y i n fl uence l o cal m o squi t o c ontrol pract i ces except where Federal l a nds are i nvol ved. This is true because Massachusetts State Laws are gene rally m o re restrictive than their Federal counterparts. W h at follows is a brief sum m a ry of State and Federa l Laws an d reg u l atio n s wh ich m a y relate to m o sq u ito

co n tro l activ ities. 2. State Laws

a. M G L C h ap. 252 as currently am ended - Im provem e nt of Lowl ands. i t shoul d be not ed
th at th ere are ongoi ng effort s t o m odi fy th i s l a w, one i n pa rt i c ul ar i s desi gned t o requi re IPM pract i ces i n m o squi t o control

. Sect i ons 1-4. The St at e R ecl am at i on and M o squi t o C ontrol B o ard (SR M C B ) consi s t s of 3 m e m b ers represent i ng th e Depart m e nt s of Food & Agri cul tu re (DFA), Envi ronm ent a l M a nagem e nt (DEM ), and Envi ronm ent a l Prot ect i on (DEP). The SR M C B i s housed i n th e Depart m e nt of Food & Agri cul tu re. M e m b ers of the SRMCB (appointed by the com m i ssione rs of their respective departm e nts) receive no additional com p ensation fo r th eir serv ice o n th e SRMCB, b u t are en titled to an y ex p e n s es in cu rred in th e p e rfo rm an ce o f th eir d u ties. Al though not requi red by th i s st atut e, th e SR M C B el ect s one m e m b er t o serve as C h ai rm an. The SR M C B has th e authority, under this chapter, to (1) drain or flow (flood) a lowland with mu ltiple ownerships, (2) rem ove obstr uct i ons i n ri vers or stream s l eadi ng t o l o w l a nds, or (3 ) eradicate (abate) m o squitoes in infested areas whenever it considers such activities to be necessary or useful. This chapter requires that the SRMCB m a ke an annual report. Em pl oy ees (engi neers, assi st ant s , agent s , et c.) m a y be hi red by th e SR M C B t o carry out th e provi si ons i n th i s chapter. These parties are em powered to en ter an y p r iv ate lan d wh ich th e SR MCB wishes to exam ine or survey. Section 4A. The Com m onwealth, acting th rough a State departm e nt or the Metropolitan District Co m m i ssio n , an d an y mu n i cip a lity, m a y, in its p r o p r ietary cap acity, tak e p a rt in lo wlan d im p r o v e m e n t s d e scrib e d in this chapter. In their governm e ntal capacity, these agencies/municipalities m a y take such action when the public health, safety, or convenience will be prom oted by lowland im provem e nts. The im provem e nts m a de mu st be in accordance with Section 5A of this ch apter. A petition by proprietors for lowland im provem e nt does not require a

m a jority rule. The governing bodies of the agencies/muni cipalities mu st act on the petition. Notice of a hearing before the SRMCB will be given to all petitioners, gove rning bodies, and to all known proprietors whose landwo u l d b e affected b y su ch im p r o v e m e n t s. Mu n i cip a lities are au th o r ized to raise an d ap p r o p r iate m o n e y fo r th e i m provem e nt s. Sectio n 5

. Th e m a j o rity (in eith er v a lu e o rarea) o f p r o p r ieto rs o f an y area, m a y p e titio n th e SRMCB to im prove the area. Upon receipt of the petition and appropr iate fees, the SRMCB will i nvestigate and survey the land to determ ine the practicability and advisability of the proposed im provem e nts. If the im provem e nts are deem ed practicable and advisable, the SRMCB will give public notice of the petition in a regional newspaper and by registered m a il to each known owner, st ating the date of a hearing to be he ld by the SRMCB. After the hearing and upon the SRMCB' s approval of the proposed im provem e nt s, the SRMCB will determ ine whether a reclam ation district is necessary. If a district is recom m e nded, the SRMCB will a ppoint 3, 5, or 7 district com m i ssioners to form a reclam ation district. Com m i ssioners will receive no m o re than ten dolla rs for each day of actual service plus

com p ensat i on for expenses i n curred i n th e perform ance of th ei r dut i e s. The di stri ct i s responsi b l e for pay i ng such

com p ensat i on and expenses, as wel l as th e actual cost of i m provem e nt s. The di stri ct mu st rei m burse th e SR M C B ' s contri but ors th e m oney th at was expended for i m provem e nt s. However, th i s does not i n cl ude any m oney th at was given to the district for im provem e nts, but returned to the SRMCB becau se it was not needed or used. The SRMCB

m a y fire and hire co m m i ssioners for cause. Sect i on 5A. The SR M C B m a y det e rm i n e th at al though i m provem e nt s shoul d be m a de, a recl am at i on d i strict n eed n o t b e fo rm ed . W h en th e SRMCB is p e titi o n e d b y an ag en cy/mu n i cip a lity (as d e scrib e d in Sectio n 4A), it will notify the petitioners of th e estim ated expense of the proposed im provem e nts. Once m oney is received to cover the expense, the SRMCB will designate a nam e under which im provem e nts will be m a de and sends the

m oney t o th e St at e Treasurer who hol ds i t i n a speci al fund. W h en needed, th e m oney m a y be di sbursed on warrants drawn by the SRMCB. The SRMCB will a ppoint one or m o re com m i ssioners to oversee the im provem e nts. The com m i ssioner(s) receive a com p ensation (fixed by the SRMCB), plus expenses incurred in the perform ance of their duties. The SRM C B has th e authori t y t o hi re and fi re com m i ssioners for cause. Any excess funds are retu rned t o th e contri but ors (i n proport i on t o th ei r contri but i ons). If funds contri but ed are i n suffi ci ent t o

co m p lete th e im p r o v e m e n t s, th e SRMCB will n o tify th e co n trib u t o r s o f th eir sh ares o f th e ad d itio n a l co st. Im provem e nts will not continue until these additional funds ar e received by the SRMCB. In order to carry out the im provem e nts, the SRMCB will have the powers conferred under Sections 2, 3, 4, 5 (except reim bursem e nt ofexpenses), and 8. C o m m i ssi oners have th e powers c onferred under Sect i ons 12 a nd 13 (provi ded any propert y tak e n b y em in en t d o m ain is tak e n in th e n a m e o f th e mu n i cip a lity, an d th e mu n i cip a lity (1 ) au th o r izes th e tak i n g , (2 )

assu m e s liab ility fo r d a m a g e s, an d (3 ) h a s co m p lied with all laws co n cern i n g lan d tak i n g ) . Mo n e y fo r wh ich th e

municipality is liable m a y be contri buted by persons benefited by the im provem e nts, in proportion to their resp ectiv e b e n e fits, o ro th e rwise. An y mu n i cip a lity wh ich h a s with d r awn fro m a m o sq u ito co n tro l p r o j ect m a y, with approval of the board and upon such conditions as the board my prescribe, rejoin by public vote. Sect i on 5B . Local B o ards of Heal th (i n areas not i n m o squi t o control di stri ct s), and m o squi t o control di stri ct com m i ssi oners m a y det e rm i n e a m o squi t o breedi ng area t o be a publ i c nui sance. They m a y gi ve th e owner of the area a written notice stating that a m o squito breeding area exists on thei r land, causing a public nuisance. The
not i ce shoul d al so gi ve tr eat m e nt m e thods and set a deadl i n e for abat em ent
. If th e owner refuses t o abat e, th e B o ard of Heal th or th e m o squi t o control di stri ct com m i ssi oners m a y abat e th e nui sance (i n a m a nner approved by th e SR M C B ) . In doi ng so, th ey m a y hi re al l necessary assi st ant s who m a y ent e r upon th e l a nd for abat em ent purposes. Sectio n 6

. Fo r th e p u rp o s e o f o r g a n i zin g a m o sq u ito co n tro l d i strict, th e d i strict co m m i ssio n e rs will call a

m eet i ng of th e propri e t o rs of th e l a nds t o be i m proved. A m a jori t y i n i n t e rest (i n ei th er propert y val u e or area) mu st b e p r esen t at th e m eetin g , o th e rwise th e m eetin g will h a v e n o p o w er to act. At th e m eetin g , a tem p o r ary clerk an d a

m oderat o r are el ect ed. The m oderat o r subm i t s th e quest i on of organi zi ng a recl am at i on di stri ct (under th e provisions of this chapter) to the proprietors. If accepted by a m a j o rity vote, the propr ietors will then elect, by ballot, a district clerk and treasurer (one year term s), as well as 3-m e m b er prudential com m ittee (three years term s;

one m e m b er is replaced every year). At each annual m ee ting, elections will be held to replace the clerk, the
tr easurer, and one m e m b er of th e prudent i a l com m i t t ee. At m eet i ngs, th e di stri ct m a y borrow m oney for necessary expenses, and m a y i ssue not es, pay abl e i n not m o re th an t w o y ears. These not es are subject t o th e provi si ons of Section 10 and MGL Chapter 44. The proceed s will be held by the district treasurer. Su b s eq u e n t m eetin g s will b e called b y th e clerk at th e req u e st o f th e co m m i ssio n e rs o rat least two propri e t o rs. If th e cl erk negl ect s or refuses t o cal l th e m eet i ng, th e m eet i ng m a y be cal l e d upon a warrant from a justice of the peace. Notices of m eetings mu st be posted in two or m o re public places or should be m a iled to each proprietor 7 days before the m eeting. Vacancies in the office of clerk, treasurer, or m e m b er of the prudential

com m ittee m a y be filled at any legal m eeting. If nece ssary, the prudential com m ittee m a y appoint a person to
tem porarily fill a position until an election can be held or until the officer is no longer disabled.The prudent i a l com m i t t ee i s i n charge of expend i tu res for m a i n t e nance of th e i m provem e nt s, and exerci ses th e authori t y conferred upon th e di stri ct by l a w. The treasurer receives the district' s m oney (except as otherwise specified in S ections 6 to 14A). He/she

m a kes paym ents under the direction of the district or the prudential com m itt ee, in accordance with the requirem e nts of Sect i ons 1 t o 14B and M G L C h apt e r 44. B y -l aws m a y be adopt ed by a di stri ct form ed under th i s sect i on. These by -l aws are subject t o th e approval of th e SR M C B

. The di stri ct has th e ri ght s and powers authori zed t o i t under Sect i on 14A for carry i ng out and

m a in tain in g im p r o v e m e n t s. Th e m e m b ers o f th e d i strict are th e o w n e rs o f lan d lyin g with in its lim its. A district will not be dissolvedwithout authoriza tion by the General Court. Th is authorization will not be g i v e n u n til a p r o v i sio n h a s b een m a d e fo r p a ym en t o f th e o b lig atio n s o f th e d i strict. Sect i on 6A. Any di stri ct est abl i s hed under th i s chapt e r m a y buy th e fol l o wi ng i n surance coverages: (1) liability for bodily injuries and dam a ge to property; (2 ) liab ility fo r wo rk m e n ' s co m p en satio n ; (3) fi re i n surance (coveri ng, am ong other th i ngs, l o ss by destruct i on or dam a ge t o bui l d i ngs or personal propert y ) ;

an d (4 ) m o to r v e h i cle co llisio n in su ran ce. Sectio n 7

. On ce a d i strict is o r g a n i zed , th e co m m i ssio n e rs will m a k e su rv eys an d in v e stig atio n s an d will prepare a plan delineating dist rict boundaries and proposed im provem e nts. They will determ ine the total expense of the proposed im provem e nts, along with the percentage to be paid by each proprietor (determ i ned by estim ating the b e n e fits less an y d a m a g e s cau sed b y th e im p r o v e m e n t s. Th e p r o p r ieto r will b e award e d an y d a m a g e s in ex cess o f th e b e n e fits. Th e co m m i ssio n e rs will rep o r t th eir p l an an d estim ates to th e SRMCB wh o will ap p r o v e , d i sap p r o v e

or m odi fy th em . The com m i ssioners mu st also subm it a copy of th eir determ ination to each propr ietor (hand-delivered or by reg i stered m a il). A p r o p r ieto r h a s 1 5 d a ys in wh ich to file an y o b j ectio n s with th e SRMCB. Th e SRMCB will notify all proprietors of the receipt of an y objections within 30 days; and at least 7 days after this notice is given, the SRMCB will h o l d a m eetin g to co n s id er th e o b j ectio n s an d to m a k e a d ecisio n . If th e p r o p r ieto rs are n o t satisfied with this decision, they m a y pe tition the County Superior Court. Once the percentages to be paid by each proprie tor have been determ ined, th e SRMCB will record in theR e gi stry of Deeds (1) a descri pt i on of th e area t o be i m proved; (2) a copy of a pl an; and (3) an est i m at e of th e

am ount to be assessed from each parcel. Section 8. If the SRMCB feels that certain im provem e nts will benefit public health as a whole and should,
th erefore, be pai d by th e C o m m onweal th , th e SRMCB mu st sep a rately estim ate th at part of th e expense, t o be i n cl uded wi th other est i m at es under M G L C h apt e r 29, Sect i on 4. Section 9. After recording the descrip tion, plan and estim ate (from Section 7), the com m i ssioners will call

a m eet i ng t o deci de on th e m e thod of fi nanci ng (opt i ons are i n cl uded i n Sect i ons 10 and 11). Approval of proposed expendi tu res requi res a m a jori t y vot e of a body of propri e t o rs represent i ng a m a jori t y i n t e rest i n both acreage and value of the district' s area. The district com m i ssioners m a y petition the county com m i ssioners to vote to pay for the first expenditures i nvol ved i n m a ki ng i m provem e nt s. Upon approval , th e c ount y tr easurer m a y i ssue bonds or not es, pay abl e wi th i n 25 years to defray expenses. Paym ent of principal and inte rest will be m a de by the county and repaid to the county by th e di stri ct
. Sect i on 10. The di stri ct m a y vot e t o adopt any of th ree m e thods of fi nanci ng. It m a y rai s e m oney , by

assessm ent or contri but i on, and deposi t th e funds requi red t o cover th e est i m at ed expenses wi th th e St at e Treasurer (pay m e nt s are m a de as provi ded i n Sect i on 14). The di stri ct m a y t a ke out a t e m porary l o an i n ant i c i p at i on of

assessm ents from district m e m b ers and, thereby, pay for th e im provem e nts as the work is perform ed. The district

m a y issue notes or bonds, payable for the am ount of the es tim ated expense, on condition that the initial paym ent is

m a de wi th i n 5 y ears of th e i ssue dat e , and th at th e ent i r e am ount i s pai d wi th i n 25 y ears. Indebt edness i s subject t o M G L C h apt e r 44 and other M G L' s appl i cabl e t o not es and bonds of di stri ct s. Money received from the sale of notes and bonds will be deposited with the St ate Treasurer. The State Treasurer will credit the district account for any di strict expenses that benefit the pub lic health of the Com m onwealth. Money

rem a in in g after p a ym en t o f th e to tal ex p e n s es will b e p a id to th e d i strict treasu r er to red eem o u t stan d i n g n o t es an d bonds. Section 11. The district clerk will certify to the assessors the am ount of m oney voted to be raised and paid annually (on account of the interest and principal due) along with the am ount to be paid by each proprietor. A copy of this certification mu st be filed with the SRMCB. The certified am ount will be assessed from the land of the p r o p r ieto rs an d will b e co m m itted to th e lo cal tax co llecto r s. Each week , th e tax co llecto r s will rem it th e m o n e ycollected from the assessm ents to the di strict treasurer. Assessm ents will be considered a financial obligation under law, upon the recording of the description, plan and estim at e (under Section 7), and will continue for two years as of July 1 of the year of assessm ent (i.e., reassessm ents are m a de every 2 years). Sect i on 12. If Sect i ons 1-7 have been com p l i e d wi th , and pay m ent s for expens es have been arranged, th e

co m m i ssio n e rs will carry o u t th e im p r o v e m e n t s, as ap p r o v e d b y th e SRMCB. Th e co m m i ssio n e rs m a y h i re p e rso n s t o perform th e work under th ei r di rect i on. If i m provem e nt s are for publ i c use, th e com m i ssi oners m a y t a ke l a nds,

easem ent s , and ri ght s i n l a nds (under M G L C h apt e r 79), and m a y purchase and convey propert y wi th i n and bey ond
th e l i m i t s of th e C o m m onweal th i f necessary . Any person dam a ged i n hi s propert y (by an act i on under th i s and th e fo llo win g sectio n ) , m a y reco v e r d a m a g e s fro m th e d i strict (as p r o v i d e d in MGL Ch ap ter 7 9 ) . Th ese d a m a g e s will

co n s titu te a p a rt o f th e to tal ex p e n s e o f th e im p r o v e m e n t s. If th e com m i ssi oners fi nd i t necessary t o regul at e wat e r l e vel s by operat i ng fl oodgat e s or dam s on th e l a nd of a person not a party to the proceedings (e.g., a pers on outside the district), th e com m i ssioners mu st give reasonable notice to the proprietor. The proprietor m a y appeal this work by petitioning the County Superior Court within 30 days after receipt of the no tice. Until the appeal is determ ined, the com m i ssioners mu st suspend the work. Th e co m m i ssio n e rs are req u i red to su b m it to th e SRMCB th e b ills in cu rred in m eetin g th e co st o f req u i red im provem e nts (under Section 14B), on a m onthly basis. Once inspected and approved by the SRMCB, these bills will be rewarded to the County or State Treasurer who will m a ke paym ent from available funds. The SRMCB mu st also ap p r o v e b ills fo r m a in ten a n ce o rfu rth e r im p r o v e m e n t s rep o r ted b y th e p r u d e n tial co m m ittee an d th e

co m m i ssio n e rs (as p r o v i d e d in Sectio n 1 4 A ). On ce ap p r o v e d , p a ym en t will b e m a d e b y th e d i strict treasu r er. Sect i on 14A. A recl am at i on di stri ct organi zed under th i s chapt e r m a y vot e t o undert ake further i m provem e nt s, and t o i n cur debt (as provi ded i n Sect i on 10) . Orig in al im p r o v e m e n t s mu st b e co m p leted b e fo re th is vot e i s passed. The di stri ct m a y al so vot e t o request th e SR M C B t o appoi nt com m i ssi oners t o carry out th ese further i m provem e nt s (as provi ded i n Sect i on 5). Or, th e di stri ct m a y authori ze i t s prudent i a l com m i t t ee t o carry out . th ese further i m provem e nt s. In ei th er case, both th e prudent i a l com m i t t ee and th e com m i ssi oners act i ng under this section will have the sam e powers as authorized under Section 5. The district w ill notify the SRMCB of their

v o t e an d th e p r u d e n tial co m m ittee/co m m i ssio n e rs will su b m it to th e SRMCB its/th eir p l an s fo r carryin g o u t th e im p r o v e m e n t s. Assessm en ts fro m d i strict m e m b ers to p a y fo r th e im p r o v e m e n t s (m o d i ficatio n s ) will b e m a d e in
th e m a nner provi ded i n Sect i on 11.Sect i on 14B . No person obt ai ni ng addi t i onal wat e r power or wat e r by th e work cont em pl at ed i n Sect i on 1 - 1 4 B will g a in th e rig h t to its u s e, n o rm a y a p e rso n b e en titled to co m p en satio n if th e ad d itio n a l water is reclaim e d

. No wat e r power m a y be devel oped by a di stri ct under th i s chapt e r except by vot e of th e di stri ct and approval of th e SRMCB. Anyone who obstructs or injures any structure constr ucted under the provisions of Sections 1 - 14B will be fin e d n o t less th an ten d o llars. In ad d itio n , th e SRMCB m a y attem p t to reco v e r fro m th e p e rp etrato r an y d a m a g e s incurred. The provisions in Section 5A w ill govern the disposition of m oney recovered. The m a yor and alderm en or selectm e n will receive two dollars for each day of serv ice. The city or town clerk will receive (for recording the pe tition), the fee provided by Clause (68) of Section 34 of MGL Chapter 262. Any part y aggri e ved by th e m a y o r' s and al derm en ' s or sel ect m e n' s refusal t o m a ke such an order, m a y petition the county com m i ssioners. The c ounty com m i ssioners will proceed as if the petition had been originally filed with th em . Sect i on 24. Greenhead fl y control project s m a y be est abl i s hed, wi th th e approval of th e SR M C B , i n any town or city along the seacoast, by vote of the city council/s electm e n. By the sam e vote, any two or m o re adjoining cities o rto wn s m a y fo rm a d i strict with in th eir co m b in ed areas. For these areas, the SRMCB will appoint 3 distri ct com m i ssioners. They will be paid a fixed

com p ensation, not exceeding five dollars per day, along with other expenses incurred in the perform ance of their d u ties. Co m p en satio n an d ex p e n s es will b e p a id b y th e d i strict. Th e SRMCB m a y fire an d h i re Co m m i ssio n e rs fo r

cau se. Th e d u ties o f th e co m m i ssio n e rs will b e estab lish e d b y th e SRMCB. Vot e s t o form a di stri ct are bi ndi ng for fi ve y ears. Any ci t y or t o wn m a y vot e t o wi thdraw from th e di stri ct wi th i n 60 day s , but not l e ss th an 10 day s , of any "anni versary dat e " of i t s ori g i n al vot e. They mu st not i f y th e SRMCB with in th is tim e fram e , as well. An y city o rto wn m a y v o t e to j o in an ex istin g d i strict, with th e ap p r o v a l o f th e SRMCB. Each project will determ ine its m a ximu m annual budget, and will report its determ ination to the SRMCB. In th e case o f d i stricts, th e co m m i ssio n e rs will m a k e th is d e term in atio n . Th e SRMCB will, in tu rn , d e term in e th e proportionate share of the budget that each m e m b er municipality is to be held accounted for. The SRMCB will then report its determ ination to the treas urer of each m e m b er municipality. One third of the budget will be paid by the m e m b er municipalities within a distri ct in proportion to the saltm a rsh area within its boundaries. Another third will be paidby the Com m onwealth. The fi nal third will be paid by the m e m b er towns/cities within a district in proportion to their respective ta xable valuations. A project consisting of a sin g l e mu n i cip a lity is n o t en titled to su b s id y b y th e Co m m o n w ealth

. Paym ents of each municipality’s share of the budget w ill be m a de to the State Treasurer. Towns/cities m a y also raise m oney in advance to anticip ate its liability. These funds would be held by the State Treasurer, as well,

an d wo u l d b e cred ited ag ain s t th e mu n i cip a lity’s liab ility. Projects will be allocated funds annua lly from the State Treasury to elim in ate or control Greenhead flies in accordance with the predeterm i ned contro l strategy (prepared a nd devised by the SRMCB to effect the greatest

m easure of relief). Such work mu st be perform ed unde r the direction and control of the SRMCB. Additional control efforts m a y be carried out as long as additional funding is provided, such as funds voluntarily deposited with the State Treasurer for such purposes. b. M G L C h ap. 132B -- Pest i c i d e C ontrol Act (From th e C ode of M a ssachuset t s R e gul at i ons 333 C M R2.00 -10.00) General Inform ation The M a ssachuset t s Pest i c i d e C ontrol Act was i n se rt ed as M G L C h ap. 132B of th e Act s of 1978 (C hapt er 3)

as an em ergency l a w and t ook effect i m m e di at el y . The purpose of th e Act i s t o have th e l a ws of th e C o m m onweal th conform wi th federal requi rem e nt s on re g i stratio n an d certificatio n o f p e sticid es as set fo rth in th e Fed e ral Insect i c i d e, Fungi ci de, and R odent i c i d e Act , Publ i c Law 92-516, as am ended, (FIFR A ), and th e federal regul at i ons th ereunder. To th i s end, th e M a ssachuset t s Pest i c i d e C ontrol Act creat es adm i ni strat i v e m echani s m s t o regul at e th e l abel i ng di stri but i on, sal e , st orage, tr ansport a t i on, use and appl i cat i on and di sposal of pest i c i d es. The M a ssachuset t s Act also establishes standards and sets forth prohibitions with regard to each regulatory function. The responsibility for i m pl em ent i ng th e com m a nds of th e M a ssachuset t s Pest i c i d e C ontrol Act i s di stri but ed by th e Act am ong th ree governm e nt al bodi es: i

. Depart m e nt of Food and Agri cul tu re (DFA). The DFA has been desi gnat e d as th e st at e l ead agency for i m pl em ent a t i on and adm i ni strat i on of t h e Act and th e M a ssachuset t s pest i c i d e program . The Act charges th e DFA wi th a wi de range of speci fi c regul at ory funct i ons and em powers i t t o promulgate and adopt re gulations, standards and form s as are necessary for im plem entation and adm i nistration. Am ong th e dut i e s assi gned t o th e DFA by th e Act are:a. Ent e ri ng i n t o cooperat i v e agreem ent s and contract s i n m a t t e rs rel a t e d t o th e Act and FIFR A. b. Taki ng act i ons necessary t o secure for th e C o m m onweal th th e benefi t s of FIFR A and other federal l e gi sl at i on.

c. Est abl i s hi ng advi sory counci l s . d. Decl ari ng pest s and devi ces t o be subject t o th e provi si ons of th e Act

.
e. Establishing the fee and preparing and accepti ng the applications for e xperim e ntal use perm its. f. Est abl i s hi ng requi rem e nt s for l i censi ng and supervi s i ng pest i c i d e deal ers. g. Est abl i s hi ng requi rem e nt s for cert i f y i ng, l i censi ng and supervi s i ng vari ous cat egori e s of pest i c i d e applicators. h. C ontrol l i ng both st orage and di sposal of pest i c i d es. i

. Issui ng adm i ni strat i v e orders t o prevent unreasonabl e adverse effect s on th e envi ronm ent or vi ol at i ons under th e Act

. j

. Rig h t o f en try an d in sp ectio n as n eed ed to ad m i n i ster th e Act. W ith in th e DFA, th e p e sticid e regul at ory funct i ons shal l be under th e adm i ni strat i v e supervi s i on of a Pest i c i d es Program Director. ii. Pesticid e Bo ard

. Th e Act creates with in th e DFA a Massach u s etts Pesticid e B o a r d

. The Board' s responsibilities entail advising the Co m m i ssioner of Food and Agriculture with respect to the i m pl em ent a t i on and adm i ni strat i on of th e Act The B o ard al so hears appeal s of those aggri e ved by th e act i ons or deci si ons of th e DFA or th e Subcom m i t t ee of th e Pest i c i d e B o ard. The Act , addi t i onal l y , assi gns th e B o ard th e responsibility for approving a variety of departm e ntal actions within the DF A. Am ong the actions requiring Board approval are:

a. Al l regul at i ons, st andards and form s proposed by th e DFA t o i m pl em ent and adm i ni st er th e Act

. b. Appoi nt m e nt of th e Pest i c i d es Program Di rect or.

c. C ooperat i v e agreem ent s and contract s wi th respect t o th e Act and FIFR A. d. Est abl i s hm ent of advi sory counci l s .
e. Decl arat i ons of pest s and devi ces t o be subject t o th e provi si ons of th e Act

.The C o m m i ssi oner of Food and Agri cul tu re or hi s desi gnee serves as th e C h ai rm an of th e Pest i c i d e B o ard. Other m e m b ers i n cl ude th e C o m m i ssi oner of Envi ronm ent a l Prot ect i on or hi s desi gnee, th e C o m m i ssi oner of Fi sheri e s, W i l d l i f e and R ecreat i onal Vehi cl es or hi s desi gnee, t h e C o m m i ssi oner of Envi ronm ent a l M a nagem e nt or hi s desi gnee, th e C o m m i ssi oner of Publ i c Heal th or hi s desi gnee, th e Di rect or of th e Di vi si on of Food and Drugs or hi s desi gnee and th e seven persons appoi nt ed by th e Gove rnor, one of whom has been engaged i n th e com m e rci a l production of a plant-related agricultural com m odity for at least the preceding fi ve years on land owned or rented by him , one of whom has been an active com m e rcial applicator of pesticides for at least the preceding five years, one of whom has expert i s e i n th e heal th effect s of pest i c i d e use, one of whom i s a phy si ci an, one of whom i s experi enced i n th e conservat i on and prot ect i on of th e envi r onm ent , and t w o of whom represent th e publ i c at l a rge. Each m e m b er is appointed for a period of four years, except for persons appoi nted to fill vacancies, who serve for
th e unexpi red t e rm . The appointive m e m b ers of the Board receive fifty dollars for each day or por tion thereof spent in the di scharge of th ei r offi ci al dut i e s and are rei m bursed for th eir necessary expenses incurre d i n th e di scharge of th ei r official duties. iii. Su b c o m m ittee o f th e Pesticid e Bo ard

. Th e Act creates a su b c o m m ittee with in th e Pesticid e Bo ard o f th e DFA. The subcom m i t t ee i s responsi b l e for regi st eri ng a l l pest i c i d es for use i n th e C o m m onweal th and for i ssui ng al l experi m e nt al use perm i t s . The Director of the Division of Food and Drugs serves as the Ch airm an of the Subcom m ittee. Other

m e m b ers i n cl ude th e C o m m i ssi oner of Food and Agri cul tu re or hi s desi gnee, th e C o m m i ssi oner of Envi ronm ent a l M a nagem e nt or hi s desi gnee, and th e C o m m i ssi oner of Publ i c Heal th or hi s desi gnee, and one person appoi nt ed by the Governor, who has been actively enga ged in com m e rcial application of pestic ides for at least the preceding five years who is a m e m b er of the Pesticide Board.

c. 333 C M R10.03 (21-23) - Am endm ent s of 1983. Am endm ent (21) t o th e Pest i c i d e R e gul at i ons provi des a l i s t of condi t i ons th at mu st be m e t pri o r t o al l nonagri cul tu ral pest i c i d e appl i cat i ons by ai rcraft . It ca l l s for publ i c not i f i cat i on of abut t i ng Landowners 2-10 day s before th e appl i cat i on as wel l as not i f i cat i on of th e De part m e nt of Food and Agri cul tu re and th e contract or. Appl i cat i on si t e s mu st be recorded on U.S.G.S t opographi cal m a ps and records kept for 2 y ears. Am endm ent (22)deal s wi th th e ri ght of excl usi on from pest i c i d e appl i cat i ons of propert y owners and th ei r t e nant s. M e thods are outlined for requesting exclusion and fo r properly m a rking the boundaries of pr operty to be excluded. Exclusion requests are not honored if public health or agricultural threats exist or if a recently in troduced pest is being
cont ai ned. Am endm ent (23) requi res a perm i t from th e Depart m e nt of Food and Agri cul tu ral for al l pri v at e appl i cat i ons of pest i c i d e by ai rcraft . Aeri al appl i cat i ons for m o squi t o control are sp ecifically exem pted from this provi si on al ong wi th a few other cl asses of appl i cat i ons. d. M

. G.L., C h ap. 91. Sect i ons 1-63 -- W a t e rway s Th is law d o e s n o t d eal sp ecifically with m o sq u ito co n tro l b u t it d o e s co v e r v a riety o f activ ities asso ciated wi th wet l a nds. M o squi t o control i s speci fi cal l y exem pt ed from th e provi si ons of Sect i ons 19A, 59 and 59A of th i s l a w but not from other provi si ons. As am ended by C h ap. 373 of th e Act s of 1969, th e Act m a kes provi si ons so th at th e use of oi l for m o squi t o control i n any l a kes ri vers, or t i d al wat e rs or fl at s under M G L 252 i s exem pt

from th e provi si ons of Sect i on 59 and 59A of C h apt e r 91, provi ded i t conform s t o th e rul e s and regul at i ons and of th e St at e Pesticid e Bo ard

.
e. M

. G.L., C h apt e r 40. Sect i on 5 - B o ards of Heal th and Supervi s i on. C l ause (36) and (36C ) have M G L C h apt e r 40 Sec t i on 5 refers t o th e appropri a t i on of m oney by t o wns for

m o squito abatem ent: (C l a use 36). At any t o wn m eet i ng, a t o wn, whether or not a m e m b er of a m o squi t o control project , m a y appropri a t e m oney for l o wl and i m provem e nt (m odi fi cat i on) and m o squi t o abat em ent
. Out s i d e agenci es m a y be
contract ed by th e B o ard of Heal th t o carry out m o squi t o control , provi ded th e SR M C B i s not i f i e d. Thi s out si de agency is responsible for filing a detailed annual report of their m o squito control program with the SRMCB. (C l a use 36C ). A t o wn or ci t y th at i s a m e m b er of a m o squi t o control project m a y appropri a t e m oney i n addition to the am ount assessed by the project for m o squito abatem ent. The abatem en t activities mu st, however, be carri ed out under th e supervi s i on and control of th e m o squi t o control project

. f. M

. G.L., C h apt e r 131. Sect i on 40 - W e t l a nds Prot ect i on Act

. The W e t l a nds Prot ect i on Act control s th e use of fre shwat e r and coast a l wet l a nds by est abl i s hi ng a publ i c review and decision-m a king process th rough which certain activities affecting wetlands m a y be regulated. The Act i s adm i ni st ered by l o cal conservat i on com m i ssi ons (or th e m a y o r or sel ect m e n of t o wns wi thout conservat i oncom m i ssi ons), and th e Depart m e nt of Envi ronm ent a l Prot ect i on (DEP). Any proposed project th at m a y affect a wet l a nd area mu st be approved by th e l o cal conservat i on com m i ssi on. The proponent mu st appl y for a perm i t wi th the conservation com m i ssion and the DEP, who will evaluate the proposed project to determ ine whether any land is subject t o th e juri sdi c t i on of th e Act

. The Act i s com p l e m e nt ed by 310 C M R10.00, whi c h provi des th e conservat i on com m i ssi on, and DEP wi th st andard defi ni t i ons and procedures by whi c h t o i m pl em ent th e Act

. Proposed al t e rat i ons t o wet l a nd habi t a t s of rare wi l d l i f e mu st al so be revi ewed by th e Natu ral hi st ory & Endangered Species Program (see Endangered Species Act below). Mo sq u ito co n tro l activ ities are ex em p t

fro m th e p r o v i sio n s o f th e W e tlan d s Pro t ectio n Act, p r o v i d e d th at the activities are carried out in com p lian ce with Clause (36) of Section 5 of MGL Chapter 40, MGL Chapter 252, or

o f

an y sp ecial act. No n e th eless, th ere is still so m e d e b a te co n cern i n g wh eth e r th e ex em p tio n ap p lies o n l y to th e

m a i n t e nance of exi s t i ng structures or al so i n cl udes new structures. (see page 25) g. Sect i on 40A of C h apt e r 131. Inl a nd W e t l a nds R e stri ct i on Act

. Sect i on 105 of C h apt e r 130. C o ast a l W e t l a nds R e stri ct i on Act

. Th e In lan d W e tlan d s Restrictio n Act, to g e th er with th e Co astal W e tlan d s Restrictio n Act m a k e s u p th e st atut ory basi s of th e M a ssachuset t s W e t l a nds R e stri ct i on Program . The object i v e of both Act s i s t o prom ot e and prot ect th e publ i c safet y , propert y , wi l d l i f e, fi sheri e s, wat e r resources, fl ood pl ai n areas, and agri cul tu re by
restri ct i ng or prohi bi t i ng th e al t e ri ng or pol l u t i ng of i n l a nd and coast a l wet l a nds. Al though th e areas and i n t e rest s protected are basically the sam e as those prot ect ed by th e W e t l a nds Prot ect i on Act , th e W e t l a nds R e stri ct i on Act s set forth a planning program that is not dependent on a proponent' s initiative to apply for a perm it. Through the Massachusetts W e tlands Restoration Program , inland and co astal wetlands are m a pped out in each city and town. After a p u b lic h earin g , a Restrictio n Ord e r is issu ed b y th e ad m i n i sterin g ag en cy, wh ich p r o h i b its certain activ ities in th e wetlan d areas. Th e Ord e r is th en recorded i n th e R e gi stry of Deeds and i s bi ndi ng t o al l present and futu re owners of th e propert y . Two regul at i ons, whi c h correspond t o th e Act s , are 302 C M R4 and 6. These regul at i ons cont ai n th e rul e s for adopt i ng coast a l and i n l a nd wet l a nd orders. The Depart m e nt of Envi ronm ent a l M a nagem e nt i s th e l e gal authority for both Restri ction Acts. However, the adm i nistrative respons ibility has been taken on in recent years by
th e DEP. A st atut ory tr ansfer of th e M a ssachuset t s W e t l a nds R e stri ct i on Program i s pendi ng. M o squi t o control , as authori zed by M G L C h apt e r 252, i s exem pt

from th e W e t l a nds R e stri ct i on Act

.h. M

. G.L., C h apt e r 131A. M a ssachuset t s Endangered Speci es Act

. Th is Act p r o h i b its th e “tak in g ” o f rare p l an ts o ran im als. Th is in clu d e s all p l an ts o ran im als listed as Endangered, Threat ened, or Speci al C oncern by th e M a ssachuset t s Di vi si on of Fi sheri e s and W i l d l i f e. Fi nes and j a il term s m a y b e im p o s ed fo r illeg a lly tak i n g a rare sp ecies. Th is Act also p r o t ects “sig n i fican t h ab itats,” wh ich can be so desi gnat e d aft e r a publ i c heari ng process. Perm i t s mu st b e issu ed fo r an y wo rk in sig n i fican t h ab itats. The prim ary agency for determ ining rare species st atus and si gni fi cant habi t a t s i s th e M a ssachuset t s Natu ral Hi st ory & Endangered Speci es Program (NHESP) run from th e offi ce of th e Di vi si on of Fi sheri e s & W i l d l i f e. NHESP has devel oped a seri es of Est i m at ed Hab itat Map s fo r state-listed rare sp ecies (co n t ain e d in th e Massach u s etts Natu ral Heritag e Atlas ), whi c h assi st m o squi t o -control program s i n det e rm i n i ng th e presence or absence of rare or endangered speci es. Mo sq u ito co n tro l activ ities are n o t ex em p t

fro m th e En d a n g e red Sp ecies Act an d care mu st b e tak e n to ensure program s are in com p lian ce with th e Act. Bo th p e sticid e ap p licatio n s an d sto r m water d r ain a g e are

co n s id ered alteratio n s an d req u i re p e rm ittin g . i. M.G.L., Chapter 132A. Sections 13-16, 18 -- Ocean and Coastal Sanctuaries Act The following areas in Massachusetts are protected unde r the Act: the Cape Cod Ocean Sanctuary, the Cape Cod Bay Ocean Sanctuary, the Cape and Islands Ocean Sanc tuary, the North Shore Ocean Sanctuary, and the South Essex Ocean Sanctuary. Section 13 of the Act dem a rcates the ocean sanctuaries, all of which extend approxim ately
t h ree m i l e s seaward from a poi nt on t h e mean l o w wat e r l i n e. The purpose of t h e Act , as descri bed i n Secti on 14, i s t o protect each ocean sanctuary from any "...e xploitation, development, or activity th at would seriously alter or otherwise endanger the ecology or the appearance of the ocean, the seabed, or the subsoil (of the sanctuaries), or the Cape Cod Nati onal Seashore." The Ocean Sanctuaries Act does not require the issu ance of perm its other than thos e already required by law. In consequence, t h e Departme nt of Envi ronment a l M anageme nt, the State agency authorized to oversee the Act, serves as a trustee rather than as a perm itti ng agency. All other State and local perm itting agencies are responsible for conducting their activities in conform ation with the Act. Regulation 302 CMR 5.00 com p leme nts the Act. Although not specifically exem pted from the provisions of the Act, m o squito control activities are not performed within the boundaries of the ocean sanctuaries. j. Act s of Enabl i ng Legi sl at i on Est abl i s hi ng M o squi t o C ontrol Project sExcept for C a pe C od, al l 10 current and di sba nded M C Project s i n M a ssachuset t s were est abl i s hed aft e r W o rl d W a r II when m o squi t o control fi rst appeared both t echni cal l y and econom i cal l y feasi b l e on a wi de scal e. The m o st recent were the Central Massachusetts and Su ffolk County projects form ed in 1973/74. Alm o st without exception, these projects were created as a result of lobbying efforts by lo cal citizen groups who were concerned about both outbreaks of m o squito-bor ne disease (i.e. EEE) and biting a nnoyance created by high densities of

m o squi t o es. Local l e gi sl at ors and ci t y sel ect m e n or boards of heal th pl ay ed rol e s i n shepherdi ng th rough th e necessary l e gi sl at i on. The C a pe C od C h am ber of C o m m e rce was i n strum e nt al i n th e creat i on of th e M C Project on the Cape. The Board of Reclam ation ofte n assisted local citizens and legislature with th eir effo rts. esp ecially in th e case of the m o re recently established projects. The East M i ddl esex and South Shore (di s banded i n 1981) project s were form ed under C h apt e r 252 of th e General Laws. The rem a i n i ng ei ght were creat ed by speci al l e gi sl at i on (i ndi vi dual project descri pt i ons bel o w). An i m port a nt change i n th e ent e ri ng and l eavi ng procedure was m a de i n 1991 when st at e l e gi sl at i on requi red t o wns, upon joining a project, to com m it to a m i nimu m of a five-y ear m e m b ership. This provides both stability of funding to the projects and enables a m o re com p rehensive pest m a nagem e nt plan to be put in place (single-year

m e m b erships place em phasis on im m e diate results; mu lti-y ear m e m b erships place em phasis on long-term results). 3. Federal Laws Federal laws, which directly im pact on m o squito control activities, are Sections 401 and 404 of the Clean W a t e r Act and th e Endangered Speci es Act

. Al l other fe deral restri ct i ons governi ng wet l a nds and pest i c i d es are covered by M a ssachuset t s ’s l a ws, whi c h i m pose restri ct i ons, and requi rem e nt s th at are equal t o or great er th an those in com p arable federal law. The ex ception in the case of Section 404 arises because the state laws governing the di t c hi ng of wet l a nds exem pt

m o squi t o control but th e Federal C l ean W a t e r Act does not

.
a. Section 401. Clean W a ter Act: W a ter Quality Certification. Th is sectio n req u i res ap p lican ts wish in g to d i sch a rg e d r ed g e d o rfill m a terials to o b t ain a certificatio n o r wai v er from th ei r st at e wat e r pol l u t i on control agency (M assachuset t s B u reau of R e source Prot ect i on, Di vi si on of W e tlands and W a terways). Section 401 is a federal m a ndate that is im plem ented by the state, resulting in som e frictio n o v e r p r ecisely wh at d o e s an d d o e s n o t req u i re a wate r q u a lity certificate an d wh at issu es th e certificatio n can and cannot address. The i ssue i s rendered m oot for m o s qui t o control , however, as th e U. S. Army C o rps of Engineers will not perm it a m o squito-control project that does not have a wa ter quality certification. Section 401p r o v i d e s DW W with th e p o w er to in flu e n ce p e rm it ap p licatio n s in two ways: b y d e n i al o f th e req u i red water q u a lity certificatio n , an d b y issu in g th e water q u a lity certificatio n with lim itatio n s attach ed . To d a te, o b t ain i n g water q u a lity certificatio n s h a s n o t b een p a rticu l arly d i fficu lt fo r Massach u s etts m o sq u ito co n tro l p r o g r am s. b. Sect i on 404. C l ean W a t e r Act (1972). Th is Fed e ral Act calls fo r a system o f p e rm ittin g to b e carried o u t b y th e U. S. Army Co rp s o f En g i n eers with a rev i ew o f all p e rm it ap p licatio n s b y ap p r o p r iate state an d fed e ral ag en cies. Th e m o sq u ito -co n tro l activ ities, whi c h requi re a perm i t under Sect i on 404, are as fol l o ws: a) C u t t i ng or cl eari ng new m o squi t o di t c hes i n t i d al areas bel o w m ean hi gh wat e r. b) Pl aci ng m a t e ri al excavat ed from exi s t i ng or new di t c hes on sal t m a rshes or freshwat e r wet l a nds. The Corps developed a draft plan in the early 1980' s outlining procedures for issuing general perm its for

m a intenance work (i.e. ditch cleaning) in existing m o squito ditches in each MC project. This plan was eventually shel ved pendi ng th e preparat i on of a GEIRt o serve as a gui de. Accordi ng t o 1986 correspondence t o th e Norfol k C ount y M C P from th e Sect i on C h i e f of th e R e gul at ory B r anch of th e Operat i ons Di vi si on, th e C o rps does not requi re a perm i t under Sect i on 404 for di t c h cl eani ng provi ded th e spoi l i s scat t e red at a depth of no m o re th an 3 inches. The quest i on of perm i t requi rem e nt s for new constr u c tio n in Massach u s etts’s salt m a rsh e s, su ch as th e OM W M project s i n Essex and Pl y m outh C ount i e s, rem a i n s an am bi guous i ssue. The Audubon OM W M M a nual (p. 2-2) i ndi cat es th at , i n addi t i on t o th e C o rps perm i t , perm i t s are requi red from th e Di vi si on of W a t e rway s, Offi ce of Envi ronm ent a l Affai r s and a Let t e r of C onsi s t e ncy from th e Offi ce of C o ast a l Zone M a nagem e nt . Int e ragency correspondence suggests that even agency heads are unclear about the legality of any of these requirem e nts when

m o squi t o source reduct i on work i s i nvol ved. However, i n current pract i ce th e C o rps i s not i ssui ng perm i t s for OM W M project s wi thout th ese t w o docum ent s .
c. Endangered Speci es Act

. Thi s act i s desi gned t o prot ect th reat ened and endangered speci es as l i s t e d on th e Nat i onal Hi st ori c R e gi st er Suffol k C ount y has had t o use B t i i n st ead of Al t o si d i n areas where th e B l ue-spot t e d sal a m a nder ( Ambyst oma la tera le) and th e banded bog ski m m e r ( Willia mso n i a lin tn eri ). Other project s, such as B r i s t o l C ount y M C P, have requested advice on osprey (Horseneck B each in W e stport) and the yellow-spotted turtle but have not had to m odify their proposed work because of these anim als. In both cases Bristol County was doing ditch m a intenance. Shouldth e project have been proposi ng l a rvi c i d i ng or m o re ext e nsi v e source reduct i on work, th ere i s a chance th at th ei r request woul d have been deni ed.

W i th th e Suffol k C ount y l a rvi c i d i ng program , th e i ssue of th e effect s of Al t o si d, an i n sect horm one m i m i c, on reproduct i on i n am phi bi ans has been th e dri v i ng force behi nd th e deci si on t o not al l o w i t s use. The sci e nt i f i c claim s for such effects are lim ited and m o re research in this area is required. In Pl y m outh C ount y , proposed drai nage m a i n t e nance was hal t e d by th e l o cal conservat i on com m i ssi on because they felt that the drainage threatened the pools them selves, regardless of the presence of endangered speci es. W h ether or not al l vernal pool s deserve com p l e t e prot ect i on rem a i n s a m a t t e r for research and debat e . The net effect of the Endangered species act on m o s qui t o control has been sm al l , but has provi ded another

m eans of anal y z i ng th e envi ronm ent a l effect s of m o squi t o control

. research on th e effect s of source reduct i on on non-t a rget s i s l acki ng and th i s l ack shoul d be addressed. B

. C u rrent M o squi t o C ontrol Program s i n M a ssachuset t s 1. Form al M o squi t o C ontrol Project s Of th e 351 Towns i n M a ssachuset t s , 158 (or 45%) current l y bel ong t o th e 9 organi zed M C . These project s and the towns included in each are illustrated topographically in Fig. 1. Each pr oject is m a naged by a superintendent who i s hi red and supervi s ed by a B o ard of C o m m i ssi oners represent i ng th e t o wns i n cl uded i n th e project . B o ard

m e m b ers are appoi nt ed by th e B o ard of R ecl am at i on for desi gnat e d t e rm s (usual l y 3-5 y ears). M e m b ers are unpai d except for up t o $75 per m eet i ng i n expenses. B o ards general l y m eet once or t w i ce m onthl y t o authori ze m a jor expendi tu res and t o revi ew pol i c y and program progress. Questionnaires were sent to each MC Project in both 1985 and in 1996 (copies in Appendix 1). The project s’ responses t o th e quest i onnai r e form ed th e basi s for th e fol l o wi ng sum m a ri es. The State Reclam ation and Mosquito Control Bo ard exercises responsibility over all 9 projects. This responsibility includes, but is not necessarily lim it to, the following: 1. R e vi ew and approve budget s 2. Adm i ni st er project funds (pay rol l , process purchases, et c.) 3. R e vi ew program pl ans 4. Appoi nt com m i ssi oners 5. Issue control pol i c i e s and recom m e ndat i ons6. Adm i ni st er em ergency control funds provi ded t o project s from th e governor' s or l e gi sl at ors

em ergency funds 7. Provi de advi ce and gui dance when request ed by project s or t o wns 8. M oderat e di sput es 9. Assi st t o wns seeki ng t o joi n or organi ze a fo rm al project or t o wi thdraw from an exi s t i ng project 10. Serve as a l i a i s on bet w een project s and other st ate and federal agencies and in legislative m a tters M o st project s i ndi cat ed sat i s fact i on wi th th e adm i ni strat i v e arrangem e nt and th e current funct i oni ng of th e SR M C B

. Suggest i ons for i m provem e nt cent e red around th e B o ard provi di ng m o re com p rehensi v e servi ces t o th e project s (thi s woul d requi re m o re st aff) and m o re effi ci en t and responsi v e st aff for deal i ng wi th project budget s . More form al m eetings with all pr ojects to foster better com munication and occasional attendance of Board representatives at project com m i ssion m eetings were a com m on them e. Al l project s have a B o ard of C o m m i ssi oners appoi nt ed by th e SR M C B

. They represent th e vari ous t o wns within each project and exercise general control over the project. Their specific role involves, but is not necessarily lim ited to th e fo llo win g : 1. Appoi nt th e project superi nt endent 2. Approve th e appoi nt m e nt of al l perm anent project personnel 3. Approve pay r ol l and si gn al l i nvoi ces pri o r t o processi ng by th e SR M C B 4. R e vi ew and set pol i c y 5. R e vi ew budget s and sal a ri es 6

. Serv e as liaiso n b e tween th e p r oject and the towns they represent 7. Provi de advi ce t o project superi nt endent 8. M oderat e di sput es The project s fi nd th i s adm i ni strat i v e structure t o be responsi v e and appropri a t e . The wi de range of expert i s e represent e d by th e com m i ssi on m e m b ershi p bri ngs a broad i n form at i on base t o bear on i m port a nt fi nanci a l and operat i onal i ssues. The superi nt e ndent s m a ke al l day

- t o -day operat i onal deci si ons concerni ng when and where to institute control and what m e thods to use. The Ni ne M o squi t o C ontrol Project s of M a ssachus et t s (see Tabl es 1 and 2 for budget fi gures present e d i n descri pt i ons):B e rkshi r e C ount y M o squi t o C ontrol Project C r eat ed under: C h apt e r 456 of th e Act s of 1945 Area i n cl uded: The t o wns of B ecket , Hi nsdal e , Lanesboro, Ot i s , R i chm ond, and Sheffi el d and St ockbri dge. Annual Assessm ent: 35 cents on each one thousand dollars of taxable valuations; sum s so expended i n proport i on t o th ei r respect i v e val u at i ons. Am endm ent to Assessm ent: Chapter 459 of the Ac ts of 1970--20 cents on each one thousand dollars of th e equal i zed val u at i ons; sum s so expended i n proport i on t o th ei r sai d val u at i ons.
Form ed in post-W a r 1945 under the leadership of th e State Senator from Pittsfield. This countywide p r o j ect o r ig in ally h a d 3 2 m e m b er to wn s. All ex cep t 8 o f th ese to wn s with d r ew in th e early 8 0 ' s after th e p a ssag e o f Proposition 2 1/2 and considerable negativ e publicity. One additional town left later on. Since 1985, four towns have joi n ed th e project and four have wi thdrawn. Of th ese one (Hinsdale) withdrew a nd th en rejoi n ed and another (Pittsfield ) j o in ed an d th en with d r ew. Th e reaso n s fo r with d r awin g cen tered o n co st, wh ile th e reaso n s fo r j o in in g centered on municipalities respondi ng to resident com p laints. Spri ng hat c h Aedes are th e m a jor probl em experi enced i n th i s m ount ai nous t e rrai n . Som e refl ood Aedes and Cq . pert urbans probl em s al so exi s t
. In 1985 approxi m a t e l y 70% of th e budget was devot ed t o source reduct i on th rough hand cl eani ng of di t c hes. B y 1996, approxi m a t e l y 70% of th e budget i s devot ed t o l a rvi c i d i ng and adulticiding. The program is evaluated by all four standard m onitoring m e thods. Over the past decade increasing c itizen concern regarding pesticide use has been the m o st im portant change faced by the project. At pres ent, providing the desired control servi ces under very tight funding is given as
th e m o st i m port a nt chal l e nge faci ng th e project

.
B r i s t o l C ount y M o squi t o C ontrol Project C r eat ed under: C h apt e r 506 of th e Act s of 1956 Area included: All the cities & towns com p rising Bristol County Annual Assessm ent: 15 cents on each one thousa nd dollars of taxable valuations; sum s so expended i n proport i on t o th ei r respect i v e val u at i ons. Am endm ent to Assessm ent: Chapter 638 of the Ac ts of 1970--8 cents on each one thousand dollars of th e equal i zed val u at i ons; sum s so expended i n proport i on t o th ei r sai d val u at i ons.
Al l t w ent y t o wns i n B r i s t o l C ount y m a ke up th i s control project , whi c h was form ed i n 1959 duri ng a period of high pest densities and threat from EEE. Senator Parker of Taunton played a key role in organizing theproject . Onl y one t o wn (Dart m outh) subsequent l y wi thdrew from th e project fol l o wi ng negat i v e publ i c i t y . It rejoined several years later dur ing another EEE active period. There are approxi m a t e l y 67,000 acres of fresh wat e r swam pl and i n B r i s t o l C ount y . As i n th e case of Norfol k and Pl y m outh C ount i e s, th i s present s som e uni que probl em s. It has resul t e d i n a l a rge source reduct i on effort (78% of budget in 1995) and adu lticiding (19%) over larviciding. Salt m a rsh m o squitoes have becom e an i n creasi ngl y i m port a nt part of th e control program . Spri ng Aedes and Cq . pert urbans are m a jor pest probl em s and concern with EEE transm ission is ever pr esent. Light trap counts and cases of hum an/anim a l disease are used to evaluate the effectiveness of the program

. Over the past decade Bristol MC P has been faced with the double squeeze of increasing concern over wetlan d s alteratio n s an d in creasin g co n cern s o v e r p e sticid e u s e. W ith so u r ce red u c tio n an d ad u lticid in g b e in g th e t w o pri m ary control t echni ques used by B r i s t o l M C P, such concerns go t o th e heart of th e project ’s effect i v eness. As an exam ple, Bristol MCP switched from m a lathion to re sm ethrin for adulticiding due to public pressure to end th e u s e o f m a lath io n . Ho wev e r, resm eth r in is m o re co stly, wh ich b r in g s to th e fo re th e co n tin u i n g d i fficu lties o f budgets. Bristol MCP, like m a ny other projects, faces diffi culties in im plem enting newer control strategies due to
t i ght budget s .
C a pe C od M o squi t o C ontrol Project C r eat ed under: C h apt e r 379 of th e Act s of 1930 Area i n cl uded: The t o wn com p ri si ng B a rnst abl e C ount y Annual Assessm ent: 25 cents on each one thousa nd dollars of their respective valuations. Am endm ent to Assessm ent: Chapter 209 of the Ac ts of 1975--9 cents on each one thousand dollars of th e equal i zed val u at i ons; sum s so expended i n proport i on t o th ei r said v a lu atio n s .
The C a pe C od project was organi zed th rough th e effort s of th e C a pe C od C h am ber of C o m m e rce, begi nni ng i n 1928. Thei r m o t i v at i on was th e enhancem ent of th e recreat i onal resources of th e C a pe. Al l 15 t o wns i n B a rnst abl e C ount y have bel onged t o th e project cont i nuousl y si nce i t s form al creat i on i n 1930. There are approxi m a t e l y 20,500 acres of sal t m a rsh and 2,600 acres of freshwat e r wet l a nds on th e C a pe capabl e of support i ng

m o squi t o devel opm ent
. Th e Cap e Co d p r o j ect h a s ch o s en n o t to u s e ad u lticid es as p a rt o f th eir p r o g r am . Larv icid in g an d so u r ce reduct i on (m ai nt enance on exi s t i ng wat e r sy st em s) form th e b ackbone of t h e project . The C a pe project i s current l yconduct i ng research i n t o th e use of nat i v e fi sh as bi ol ogi cal control agent s for m o squi t o es. W h i l e l a rval survey s and l a rvi c i d e appl i cat i ons are conduct e d duri ng hal f of th e y ear, th e other hal f of th e y ear i s spent m a i n t a i n i ng th e current di t c h sy st em s (i ncl udi ng work on pi pes, cul v ert s and sl ui ceway s). M a ny t o wns’ DPW s and C onservat i on Com m i ssions utilize the project’s expertis e to help keep drainage system s ope n and running properly. Further, the C a pe C od project ’s work i s recogni zed by th e Nat i onal Fl ood Insurance Program ’s C o m muni t y R a t i ng Sy st em as

m eet i ng th e fl ood-pl ai n m a i n t e nance requi rem e nt s for t o wns t o obt ai n l o wer fl ood i n surance rat e s. Th e Cap e Co d p r o j ect u tilizes a Geo g r ap h i cal In fo rm atio n System (GIS) th at in clu d e s m a p s o f all p o t en tial l a rval habi t a t , docum ent a t i on of work done i n cl udi ng l a rvi c i d e appl i cat i on, and dat afrom adul t and l a rval survey s conduct e d at al l m o squi t o devel opm ent si t e s. Inform at i on fro m th i s sy st em i s used t o wri t e an annual report and i s

m a de available to the m e m b er towns. This project also runs a greenhead fly control program . Over 600 blue box traps are placed on the salt

m a rshes of B a rnst abl e C ount y every spri ng. R e search was conduct e d by th e project i n th e sum m e rs of 1992-1995
t o det e rm i n e th e effect i v eness of addi ng Oct e nol , an ol fact or y attractan t to th es e traps. Success with that research has resul t e d i n th i s project and others i n corporat i ng oct e nol i n t o th ei r greenhead fl y tr appi ng program s. As an in d i catio n o f th e stab ility o f th e Cap e Co d Pro j ect, all eig h t een em p l o y ees h a v e o v e r 4 years o f experi ence wi th 50% of th e em pl oy ees havi ng worked i n m o squi t o control for over 15 y ears
C e ntral M a ssachuset t s M o squi t o C ontrol Project C r eat ed under: C h apt e r 583 of th e Act s of 1973 Area in clu d e d : Th e area in Mid d l esex an d W o rcester Co u n ties in clu d i n g th e cities o f Fi t c hburg, Leom i n st er, and M a rl borough and th e t o wns of Ashl and, Ay er, Berlin, Billerica, Blackstone, Boxbor ough, Chelm s ford, Clinton, Dracut, Holliston, Hopedale, Hudson, Little ton, Lunenburg, Milford, Natick, Northborough, Sherborn, Shrewsbury , Southborough, St ow, Tewksbury , W e st borough, W e st ford, and W i l m i ngt on. Annual Assessm ent: 8 cents on each one thousand dollars of the cities' and towns' equalized val u at i ons; sum s so expended one quart er i n proport i on t o th ei r val u at i ons and th ree quart ers i n proport i on t o th ei r respect i v e areas.
Twent y -ei ght t o wns m a ke up th i s l a rge project . It was organi zed i n 1973 th rough th e effort s of several
t o wn boards of heal th and concerned ci t i zen groups. The Project has experi enced si gni fi cant tu rnover i n

m e m b ershi p . Two t o wns wi thdrew from th e project earl y on but th en rejoi n ed. Seven other t o wns wi thdrew perm anently prior to 1986, prim arily as a result of Propos ition 2 1/2 fiscal constraint s and concern over pesticideuse, though concerns about m o squi t o es com i ng i n t o th e t o wn from areas not bei ng tr eat ed pl ay ed a rol e i n Hopki nt on’s deci si on t o wi thdraw. However, Fi t c hburg, L unenburg, and Leom i n st er were joi n i ng duri ng th e sam e period, in each case due to a desire to be a part of a regional approach to m o squito control. Since 1986, an addi t i onal seven t o wns have wi thdrawn (Harvard, Lancast e r, B o y l st on, Graft on, Grot on, Northbri dge and Shi r l e y )

. The t o wns l e ft for budget a ry reasons and envi ronm ent a l concerns. Fi ve t o wns have joi n ed th e project si nce 1989, two (W ilm ington and Natick) because town program s were abandoned, one (Blackstone) because of bad m o squito problem s, one (Dracut) because of pos itive feedback from m e m b er towns, and the fifth (Stow) because they liked
th e envi ronm ent a l l y responsi b l e control t echni ques of th e Project . Towns can wi thdraw or rejoi n by a vot e at t o wn

m eet i ng but joi n i ng t o wns al so mu st be approved by th e SR M C B , whi c h m a y i m pose speci al st i pul at i ons. Up t o 10,000 acres of m i xed, freshwat e r wet l a nds and a l a rge num ber of cat ch basi ns and t i r es are tr eat ed wi th l a rvi c i d e’s (35% of t o t a l budget ) and/ or have s ource reduct i on work done (40% of budget ) . Spri ng hat c h and refl ood Aedes , and Cq . pert urbans account for th e bul k of th e pest probl em s i n th i s project . Al l st andard

m oni t o ri ng m e thods are used t o eval uat e program effect i v eness. Central Mass has assem b led an im pressive staff, w i th si x st aff m e m b ers hol di ng B S or B A degrees and several personnel havi ng m o re th an 15 y ears of m o squi t o -control experi ence. Over the past decade the Proj ect ha s worked to reduce its use of adultic ides and increased its applications

o f

larv icid es su ch as Bti. W a ter m a n a g e m e n t h a s b eengeared t o wards m a i n t e nance but wet l a nds rest orat i on i s pl ay i ng an i n creasi ng rol e . Gi ven th at m a ny t o wns have wi thdrawn from th e project due t o budget constr ai nt s, devel opi ng a m odern, cost -effect i v e control program i s th e hi ghest chal l e nge current l y faci ng th e Project

.
East M i ddl esex M o squi t o C ontrol Project C r eat ed under: M C L C h apt e r 252, sect i on 5A i n 1945. There i s no speci fi c M a ssachuset t s Law or Act whi c h nam e s th e East M i ddl esex C ontrol Project

. Area included: Twenty cities and towns in Middlesex and Norfo lk Counties including Arl i ngt on, B e dford, B e l m ont , B r ookl i n e, B u rl i ngt on, C a m b ri dge, Fram i ngham , Lexi ngt on, Li ncol n, M e l r ose, Newt on, North R eadi ng, R eadi ng, Sudbury , W a kefi el d, W a l th am , W a t e rt own, W a y l and, W e l l e sl ey , and W e st on. Annual assessm ent: Cities and towns voluntarily appropriate funding each year for m o squitocontrol servi ces. Fundi ng i s carri ed over from one fi scal y ear t o th e next
. This project was organized in 1945 as a trust agency to provide m o squito control for 6 cities and towns. The original goals for the Project cite d by the representatives of the 6 m unicipalities were to form a cooperativem o squi t o control program under th e auspi ces of th e St at e R ecl am at i on B o ard. Pol i c i e s for th e Project were set by the Com m i ssion that would be com p rised of representativ es, appointed by the State Reclam ation board, from each

municipality. The prim ary reasons cited in 1945 for organi zing the Project were the v ector potential and nuisance caused by m o squi t o es. Cu rren tly th e Pro j ect h a s 2 0 m e m b ers. Th e n e west mu n i cip a lities to j o in th e p r o j ect h a v e b een No rth R eadi ng (1991) and M e l r ose (1997). The t w ent y -m em ber com m i ssi on m eet s t w i ce a y ear. Fi ve C o m m i ssi oners serve on th e Execut i v e C o m m i t t ee, whi c h m eet s regul arl y . Fundi ng i s deri ved th rough vol unt ary appropri a t i ons. The Com m i ssion has a policy, which allows municipalities flexibility in choosing cont rol m e thods. The Project

recom m e nds a control program for each municipality. The municipality then has cont rol over which services it chooses t o fund. Al though th i s process has resul t e d i n st abl e growth si nce 1983, th e Project has hi st ori cal l y had funding lim itations because 33% of its area is urban with relatively m i nor m o squito pest problem s. Spri ng Aedes species, Ae. vexans, and Cq . pert urbans are the m a jor concerns in the district. Cu lex i n urban areas are also a concern. Ae rial larv icid in g ag ain s t sp rin g Aedes and Aedes vexans is th e larg est p r o g r am in th e di stri ct . Other program s i n cl ude l a rvi c i d i ng wi th a tr uck-m ount ed hy draul i c spray e r and port abl e spray e rs, cat ch basin larviciding in urban areas and adulticiding with tr uck-m ounted ULV aerosol spraye rs and portable aerosol and backpack m i st bl owers. B e gi nni ng i n 1994, th e Project ent e red i n t o a cooperat i v e agreem ent wi th th e Essex C ount y M o squi t o C ontrol project t o use a backhoe and operat o r for East M i ddl esex di t c h-m a i n t e nance operat i ons. The Project continues to m a intain ditches by hand in woodland areas. The Project m a intains an exte nsive surveillance operat i on, whi c h i n cl udes m oni t o ri ng adul t m o squi t o es at 50 locations. The Project record s extensive larval survey data to support it’s larval control program . Beginning in 1995 the Project augm ented its surveillance and record keepi ng program s by addi ng GIS m a ppi ng soft ware.
North East M a ssachuset t s M o squi t o C ontrol and W e t l a nds M a nagem e nt Di stri ct form erly Essex C ount y M o squi t o C ontrol Project C r eat ed under: C h apt e r 516 of th e Act s of 1958 Area i n cl uded: The area i n Essex C ount y not i n cl udi ng any ci t y or t o wn al ready a m e m b er of an organi zed m o squi t o control project

. Annual Assessm ent: 15 cents on each one thousand dollars of taxable valuations; sum s so expended one quart er i n proport i on t o th ei r val u at i ons and th ree quart ers i n proport i on t o th ei r respect i v e areas. Am endm ent of Assessm ent: Chapter 679 of the Acts of 1970 -- eight cents on each thousand dollars of equal i zed val u at i on; on quart er i n proport i on t o th ere sai d val u at i ons and th ree quart ers i n proport i on t o th ei r respect i v e areas.This seventeen-town project was established in 1965 after lobbying e fforts by citizen groups who were concerned about pest m o squi t o es. Pri o r t o 1986 four t o wns (Essex, M e rri m ac, North R eadi ng, Ly nnfi e l d ) subsequent l y wi thdrew from th e project by t o wn m eet i ng vot e due t o fi scal constr ai nt s and som e negat i v e publ i c i t y . On e o f th ese to wn s (Lyn n f ield ) rej o in ed th e fo llo win g year d u e to a p e rceiv e d in crease in p e st d e n s ities an d th reats to public health. Ten towns withdrew from the project in the late ‘eighties, pr im arily because of budget constraints. Four towns (Ipswich, Newburyport, Salisbury and Am esbur y) have since rejoined, all because of public dem a nd fol l o wi ng th e hal t of control act i v i t y (l ength of t i m e out of project vari ed from one t o th ree y ears). A hi gh proport i on of th e Essex C ount y M C P budget i s de vot ed t o sal t m a rsh m o squi t o probl em s (60%) and
th i s project has t a ken th e l ead i n worki ng wi th envi ronm ent a l i n t e rest s t o devel op OM W M pl ans and studi es i n

so m e o f its m a rsh e s. Catch b a sin s are treated with Alto sid b r iq u e ttes an d all o th e r larv icid in g is carried o u t with th e bact eri a l t oxi n B t i

. Thi s i s m o st l y i n woodl and vernal pool s i n th e spri ng and i n unm anaged sal t m a rshes. The project does little adulticiding. It al so adm i nisters a greenhead fly contro l program using box traps in several
coast a l t o wns. Al l m oni t o ri ng m e thods (i .e., com p l a i n t s , and l i ght em ergence tr aps, and l a ndi ng/ l a rval count s) are used t o eval uat e th e effect i v eness of th e program and for dai l y deci si on-m a ki ng. Essex C ount y has been a l eadi ng project i n devel opi ng Open M a rsh W a t e r M a nagem e nt as a m o squi t o control and m a rsh-rest orat i on t echni que i n th e Northeast , and has pushed t o devel op a se t of st andards for m o squi t o control in such areas as uplands ditch m a intenance th at will both standardize cont rol throughout New England and p r o v i d e a b e tter fram e wo rk fo r th e p e rm ittin g p r o cess. Not surpri si ngl y for a Project wi th a forward th i nki ng approach, Essex C ount y ’ s program , over th e past decade, has reduced adulticiding while im plem enting OMW M and increasing its ties with environm ental agencies and groups. The l o ss of several t o wns has requi red a change i n strat e gy from a regi onal t o a muni ci pal approach, a change not part i c ul arl y desi rabl e for area-wi de contro l probl em s l i k e m o squi t o es. However, th e chal l e nge of revi si ng th e Project ’s strat e gi es and t echni ques has been m e t an d its m o st im p o r tan t ch allen g e to d a y is m eetin g th e dem a nd for m a rsh rest orat i on work whi l e cont i nui ng t o m a i n t a i n a hi gh st andard for m o squi t o control

. Essex C ount y M C P changed i t s nam e i n 1996 t o th e North East M a ssachuset t s M o squi t o C ontrol and W e tlands Managem e nt District, but it will be referred to as Essex County in this report as the nam e is new and m a y not be recogni zed by readers at th i s t i m e.Norfol k C ount y M o squi t o C ontrol Project C r eat ed under: C h apt e r 341 of th e Act s of 1956 Area i n cl uded: The area i n Norfol k C ount y not i n cl udi ng any ci t y or t o wn al ready a me mb e r of an organi zed m o squi t o control project

. Annual Assessm ent: 20 cents on each one thousa nd dollars of taxable valuations; sum s so e expended on hal f i n proport i on t o th ei r val u at i ons and one hal f i n proport i on t o th ei r respect i v e areas. Am endm ent of Assessm ent: Chapter 496 of the Ac ts of 1975--8 cents on each thousand dollars of equal i zed val u at i ons; sum s so expe nded one quart er i n proport i on t o th ei r val u at i ons and th ree quart ers i n proport i on t o th ei r respect i v e areas OR th ree quart ers i n proport i on t o th ei r val u at i ons and one quart er i n proport i on to their respective areas, W H ICHEVER IS THE LESSER AM OUNT.

Twent y -t wo t o wns form ed th i s project i n 1956 and th ree m o re joi n ed i n th e earl y 80' s aft e r th e South Shore project di sbanded. Two t o wns (M i l t on and Norfol k ) l a t e r wi thdrew by a vot e at t o wn m eet i ng or ci t y counci l

. Norfol k rejoi n ed just one y ear l a t e r onl y t o wi thdraw and rejoi n agai n about 10 y ears l a t e r. W i thdrawal vot es were fuel ed by envi ronm ent a l concerns over pest i c i d e use and ne g a tiv e p u b licity. Effo rts to rej o in were p r ecip itated b y publ i c heal th th reat s, bi t i ng com p l a i n t s , and i n effect i v e i n -house control program s. Norfol k di d not l o se t o wns during the late eighties, so has had stab le m e m b ership for m o re than a decade. Over half of the project budget is spent on source re duction work. In the ‘80’ s adulticiding was stressed over larviciding but this has changed a nd now larviciding, including aerial appli cations, far exceeds adulticiding. It i s est i m at ed th at th ere are over 30,000 acres of freshwat e r swam pl and i n Norfol k C ount y , whi c h can breed

m o squi t o es, but onl y 1,087 acres are tr eat ed for spri ng- hat c h and 523 acres (there m a y be overl ap) for sum m e r reflood m o squitoes. Thirty-eight acres of salt m a rsh are under active control. All 4 standard surveillance m e thods are used to evaluate program effectiveness. Over the past decade the project has faced increasing pressure from th e public concerning pesticide use. The project has responded by provi di ng a m o re l o cal i zed response t o foggi ng request s (no m o re t o wn-wi d e appl i cat i ons are done), by i n creasi ng l a rval m oni t o ri ng t o bet t e r t a rget l a rvi c i d e appl i cat i ons, and by usi ng B t i and IGRformul at i ons for l a rvi c i d i ng. In 1996, th e Project purchased a th i r d excavat or for source-reduct i on work, went from fi ve t o ni ne fi el d st aff posi t i ons, hi red t w o seasona l em pl oy ees t o i m prove th ei r dat abase i n form at i on on wet l a nds and purchased com put er m a ppi ng equi pm ent t o bet t e r t a rget th ei r control effort s. These changes, whi l e desi rabl e envi ronm ent a l l y , have th ei r cost , and fundi ng rem a i n s a pri m ary concern.In addi t i on, envi ronm ent a l regul at i ons l i k ewi s e cause con cerns, specifically when fueled less b y scien tific reaso n and m o re by em ot i onal appeal

.
Pl y m outh C ount y M o squi t o C ontrol Project C r eat ed under: C h apt e r 514 of th e Act s of 1957 Area i n cl uded: The area i n Pl y m outh C ount y not i n cl udi ng any ci t y or t o wn al ready a m e m b er of an organi zed m o squi t o control project

. Annual Assessm ent: 25 cents on each one thousa nd dollars of taxable valuations; sum s so expended on hal f i n proport i on t o th ei r val u at i ons and one hal f i n proport i on to their respective areas. Am endm ent of assessm ent: Chap. 544 of Acts of 1970 -- 13 cents on each thousand dollars of equal i zed val u at i ons; one-hal f i n pr oport i on t o sai d val u at i on and one-hal f in proport i on t o th ei r respect i v e areas. Twenty-one towns form ed this project in 1958 dur ing a period of m a jor EEE th reat. The Plym outh County Sel ect m a n' s Associ at i on and l o cal l e gi sl at ors l e d th i s m ovem e nt t o organi ze. Seven addi t i onal t o wns joi n ed th e project i n th e earl y 1980' s when th e South Shore project di sbanded. Four of th e ori g i n al m e m b er t o wns wi thdrew by t o wn m eet i ng vot e i n th e m i d-si xt i e s. Towns mu st have been a m e m b er for at least 3 years before they can vote to leave the project. Towns th at wi thdrew di d so pri m ari l y over concer n for the im pact of the wide-scale aerial spray i ng th at th e project was carry i ng out i n th e m i d-si xt i e s. The t o wn of Hal i f ax rejoi n ed th e project i n 1985 aft e r th ey det e rm i n ed th at th e Pl y m outh C ount y project was m o re envi ronm ent a l l y sound th an th e i n -house program th ey had devel oped. Si nce th at t i m e, Abi ngt on, Hanover, Ki ngst on, and W h i t m an have al so rejoi n ed. B r i dgewat e r wi thdrew i n 1990, due t o budget a ry concerns. About 20% of th e concern of th i s Project i s wi th sal t m a rshes. W a t e r m a nagem e nt , i n cl udi ng OM W M effo rts, is u s ed to co n tro l m o st salt m a rsh Aedes . Spring and reflood Aedes recei ve a substantial am ount of
atten tio n . Cq . pert urbans , th e cattail m o sq u ito , cau ses a v e ry sig n i ficant problem but there are no recom m e nded larvicides for this species at present. Although several pr ojects contract for som e aeria l larviciding (and adulticiding i n em ergenci e s), Pl y m outh C ount y i s th e onl y project , whi c h owns fi xed wi nged ai rcraft for doi ng i t s own aeri a l work. Ground adulticiding with resm ethrin is still an im portant control strategy in this project becau se of inability to
control th e cat t a i l m o squi t o , and other speci es devel opi ng i n l a rge woodl and swam ps, wi th l a rvi c i d es. Up t o 7,860 acres of Pl y m outh C ount y ' s l a rge acreage of swam pl and are tr eat ed wi th l a rvi c i d e’s (B t i ) , t a rget ed m a i n l y agai nst spri ng Aedes . The project eval uat e s i t s control effect i v eness from com p l a i n t s , l a ndi ng count s, and l a rval count s.The past decade has clearly been one of change at Plym outh. Malathion for adulticiding gave way to

resm ethrin and the larvicide Tem e phos was replaced by Bti. There has also been an increase in the num ber of

m e m b er towns and increased service requests. Dr. Ludl am further notes that the State Reclam ation Board has becom e stronger and th ere have been i m proved t i e s wi th th e M a ssachuset t s Depart m e nt of Publ i c Heal th . The m o st i m port a nt chal l e nge faci ng Pl y m outh t oday i s th e cont i nued l ack of a control strat e gy for Cq

. pert ubans in th e larv al stages.
Suffol k C ount y M o squi t o C ontrol Project C r eat ed under: C h apt e r 606 of th e Act s of 1973 Area included: The area of Suffolk County com p rising the cities of Boston and Chelsea. Annual Assessm ent: 5 cents of each one thousa nd dollars of equalized valuations; sum s so expended one quart er i n proport i on t o th ei r val u at i ons and th ree quart ers i n proport i on t o th ei r respect i v e areas.
The Suffol k C ount y project i s th e sm al l e st i n l a nd area and encom p asses B o st on and C h el sea. The t w o other t o wns i n Suffol k C ount y , R e vere and W i nthrop, are m e m b ers of th e Essex C ount y project , whi c h predat es th i s project . The project was organi zed i n 1974 wi th strong l eadershi p from l e gi sl at ors who were resi dent s of th e di stri ct and fel t th at a pest probl em exi s t e d. M e m b er t o wn can wi thdraw from th e project th rough a m a jori t y vot e of
th e ci t y counci l and m a y o r. Pri o r t o th e organi zat i on of th e project , th e Depart m e nt of Housi ng Inspect i on

co n tracted with a p r iv ate ap p licato rto d o aerial sp rayin g o f salt m a rsh e s an d th e Park s Dep a rtm e n t d i d ad u lticid in g wi th m i st bl owers. About 30% of th e m o squi t o probl em i s associ at ed wi th sal t m a rsh Aedes but no m a rsh m a nagem e nt activities are carried out in the project’s 200 acres of breeding salt m a rsh. Contro l is done with larvicide’s. Another 130 acres of freshwat e r wet l a nd breedi ng si t e s are al so tr eat ed wi th l a rvi c i d es, as are st orm sewer cat ch basi ns. About 40% of the projects budget is devoted to adulticiding, the highest percenta ge of all the projects, but down for
th e 1980s. Program effect i v eness i s eval uat e d by com p l a i n l e vel s , l i ght tr aps, l a ndi ng rat e s, and l a rval count s are used to evaluate the eff ectiveness of the program

. Over the past decade the project has used m o re A ltosid for larviciding and reduced m a lathion use for ad u lticid in g . Pu b lic p r essu re, b o th fo r in creased sp rayin g (to elim in ate m o sq u ito es) an d d ecreased sp rayin g (to prot ect th e envi ronm ent ) pl ay s a strong rol e i n th e day

- by -day operat i on of th i s popul ous project . There are al so t w o M D C R e servat i ons i n whi c h m o squi t o -breedi ng areas ove rl ap endangered speci es habi t a t
. C u rrent l y th e projectcan use B t i i n th ese areas but woul d prefer t o swi t c h t o Al t o si d. Perm i ssi on t o m a ke th i s swi t c h has not been grant e d. B udget s B udget s for al l project s for 1993 and 1994 fi scal y ear s are provi ded i n Tabl es 1 and 2. The st andard break down by cat egory as used by th e SR C M B i s adopt ed i n th es e Tabl es. The dat aused i n th ese Tabl es were provi ded by the projects them selves. 2

. No n - Mem b er Co m mu n ities. Fo r th e in itial GEIR, all Massach u s etts To wn Bo ard s o f Health were sen t a co n cern i n g th eir to wn 's

m o squito control activities and 326 (93%) eventually responded. Fifty-seven to wns (about 38% of those respondi ng) i ndi cat ed th ey do som e m o squi t o control : 34 carry out th e control work th em sel v es usi ng t o wn personnel and 23 contract s wi th pri v at e appl i cat ors. Ni ne t een (83%) of th e 23 t o wns wi th contract ed control provi ded det a i l e d i n form at i on on cost s and pest i c i d es us ed; 23 (68%) of th e 34 t o wn-operat e d program s provi ded th is in fo rm atio n . The deci si on by non-m e m b er t o wns t o do m o squi t o control work (whi ch i n al m o st al l cases was t e m porary , ch em ical co n tro l) is m a d e b y a v a riety o f au th o r ities: 6 8 % b y th e BOH, selectm e n , m a yo r o ro th e r to wn o fficials, and 32% by a publ i c vot e. C i t i zen com p l a i n t s and a percei ved heal th th reat both wei ghed heavi l y i n deci si ons t o do
control work. Approxi m a t e l y 1/4 of th e t o wns had som e m o squi t o survey i n form at i on avai l abl e as an ai d i n th e deci si on-m a ki ng process. The m a jor cri t e ri a used t o assess th e effect i v eness of th e control work undert aken was th e p o s t-treatm e n t lev e l o f citizen co m p lain ts (9 5 % o f all to wn s). Oth e r co n s id eratio n s were, in o r d e r o f im p o r tan ce: l a rval count s, l i ght tr ap count s, l e vel of di sease, and hum an l a ndi ng count s.

Tabl e 1. B udget s for M o squi t o C ontrol Project s for Fi scal Years st art i ng i n 1993 and 1994. B udget It em 1993 1994
B e rkshi r e C ount y M C P Adm i ni strat i on a. Personnel (wages & benefi t s ) 30,000 30,000 b. Other (offi ce suppl i e s, tr avel , et c.) 500 500 Field Operations a. Personnel (wages & benefi t s ) 10,700 10,700b. Pest i c i d es 5,792 0 c. New equi pm ent 0 0 d. Other (gas, suppl i 20,000 25,792

_______ _______ e s, et c.) TOTAL $66,992 $66,992
B r i s t o l C ount y M C P Adm i ni strat i on a. Personnel (wages & benefi t s ) 75,370 75,518 b. Other (offi ce suppl i e s, tr avel , et c.) 46,918 47,888 Field Operations a. Personnel (wages & benefi t s ) 260,615 255,550 b. Pest i c i d es 34,377 31,610 c. New equi pm ent 6,125 17,412 d. Other (gas, suppl i e s, et c.) 24,121 20,162

_______ _______ TOTAL $447,526 $448,140Tabl e 1. B udget s for M o squi t o C ontrol Project s for Fi scal Years st art i ng i n 1993 and 1994 (cont i nued). B udget It em 1993 1994 C a pe C od M C P Adm i ni strat i on a. Personnel (wages & benefi t s ) 585,000 585,000 b. Other (offi ce suppl i e s, tr avel , et c.) 5,000 5,000 Field Operations a. Personnel (wages & benefi t s ) 204,495 204,495 b. Pest i c i d es 38,000 38,000 c. New equi pm ent 35,000 35,000 d. Other (gas, suppl i

_______ _______ e s, et c.) TOTAL $918,511 $918,511
C e ntral M ssachuset t s M C P Adm i ni strat i on a. Personnel (wages & benefi t s ) 123,201 125,817 b. Other (offi ce suppl i e s, tr avel , et c.) 36,546 17,241 Field Operations a. Personnel (wages & benefi t s ) 286,348 286,144 b. Pest i c i d es 15,000 37,527 c. New equi pm ent 18,154 18,970 d. Other (gas, suppl i e s, et c.) 84,181 77,731

_______ _______ TOTAL $563,430 $563,430

East Middlesex MCP a Adm i ni strat i on a. Personnel (wages & benefi t s ) 64.190 64,995 b. Other (offi ce suppl i e s, tr avel , et c.) 27,507 24,804 Field Operations a. Personnel (wages & benefi t s ) 119,156 116,734 b. Pest i c i d es 18,422 21,508 c. New equi pm ent 0 11,927 d. Other (gas, suppl i e s, et c.) 18,843 23,159

_________ _________ TOTAL $248,118 $263,126 a R ounded t o th e nearest dol l a r from report e d fi gures.
Essex C ount y M C P Adm i ni strat i on a. Personnel (wages & benefi t s ) 47,320 53,000 b. Other (offi ce suppl i e s, tr avel , et c.) 7,000 7,000 Field Operations a. Personnel (wages & benefi t s ) 188,105 188,737 b. Pest i c i d es 10,000 28,000 c. New equi pm ent 0 13,000 d. Other (gas, suppl i e s, et c.) 25,685 37,231

_______ _______ TOTAL $278,110 $326,968Tabl e 1. B udget s for M o squi t o C ontrol Project s for Fi scal Years st art i ng i n 1993 and 1994 (cont i nued). B udget It em 1993 1994 Norfol k C ount y M C P Adm i ni strat i on a. Personnel (wages & benefi t s ) 184,427 161,640 b. Other (offi ce suppl i e s, tr avel , et c.) 60,482 60,472 Field Operations a. Personnel (wages & benefi t s ) 79,040 121,939 b. Pest i c i d es 4,617 186 c. New equi pm ent 19,520 26,369 d. Other (gas, suppl i 57,331 45,556

_______ _______ e s, et c.) TOTAL $405,417 $416,162

Pl y m outh C ount y M C P Adm i ni strat i on a. Personnel (wages & benefi t s ) 127,217 144,700 b. Other (offi ce suppl i e s, tr avel , et c.) 37,388 40,000 Field Operations a. Personnel (wages & benefi t s ) 243,318 256,514 b. Pest i c i d es 30,590 31,500 c. New equi pm ent 54,625 32,100 d. Other (gas, suppl i 71,311 59,635

_______ ______ e s, et c.) TOTAL $564,449 $564,449

Suffol k C ount y M C P Adm i ni strat i on a. Personnel (wages & benefi t s ) No Fi gures suppl i e d b. Other (office supplies, travel, etc.) Field Operations a. Personnel (wages & benefi t s ) b

. Pesticid es c. New equi pm ent d. Other (gas, suppl i e s, et c.)

_______ _______ TOTALTabl e 2. Tot a l B udget s for th e ni ne M C Ps. C ount y 1993 1994 B e rkshi r e C ount y 66,992 66,992 B r i s t o l C ount y 447,526 448,140 C a pe C od 918,511 918,511 C e ntral M a ssachuset t s 563,430 563,430 East M i ddl esex 248,118 263,126 Essex C ount y 278,110 326,968 Norfol k C ount y 405,417 416,162 Pl y m outh C ount y 564,449 564,449 Suffol k C ount y No Fi gures Suppl i e d

_________ _________ TOTAL $3,492,553 $3,567,778

The choi ce of control strat e gy t o be used was genera l l y m a de by th e t o wn B OH or t o wn personnel di rect l y responsible for control activities. About 1/4 of the towns left this decision to the private applicator contracted to do
th e control work. One-th i r d consul t e d out si de publ i c advi sor such as th e B o ard of R ecl am at i on or nei ghbori ng M C project superi nt endent s. About 1/ 6 sought advi ce from pri v at e sources such as pest i c i d e sal e spersons. A si m i l a r breakdown of sources was used by t o wns t o m a ke deci si ons concerni ng when, where and how t o appl y th e prescribed pesticides, except i n th e case of publ i c and pri v at e consul t a nt s who were used l e ss (onl y by 1/4 and 1/ 10 of the towns respectively). The choice of ch em ical to b e u s ed fo r co n tro l was b a sed larg ely o n its safety to th e envi ronm ent
. Two-th i r ds of th e t o wns pr edicated their decision on this consider ation. Other concerns such as cost, effectiveness, and ease/safety of appli catio n were mu ch less im p o r tan t . No n e o f th ese criteria were u s ed in selectin g pest i c i d es by m o re th an 10 of respondi ng t o wns. Deci si ons on when and how oft e n t o appl y l a rvi c i d es were based on larval sam p ling in about 2/3 of th e towns and on a calendar spray schedule in 1/3 of the towns. Adulticide ap p licatio n s were m a in ly b a sed o n p u b lic co m p lain ts o rp r e-estab lish e d calen d a r sch e d u l es, b u t a little o v e r 5 0 % o f
t o wns were prepared t o m odi fy th ei r appl i cat i on sche dul es dependi ng on weather condi t i ons. Twent y -ni n e percent of t o wns i ndi cat ed th at schedul ed pest i c i d e tr eat m e nt s ha d actually been canceled due to adverse weather or for
other reasons. M o st t o wns (ca. 80%) rel y on newspaper and TV/ r adi o announcem ent s t o i n form th e publ i c of pendi ng pest i c i d e tr eat m e nt s. Twel ve percent m a ke no effort t o i n fo rm th e p u b lic at all. Fifty-th ree p e rcen t k eep a list o f beekeepers whose hi ves shoul d be avoi ded but onl y 3% pe rsonal l y not i f y beekeepers of pendi ng spray schedul es. Inm o st t o wns, beekeepers mu st rel y on th e sam e i n form at i on provi ded t o th e general publ i c , whi c h m eans th at 9-12% of t o wns provi de beekeepers wi th no warni ng what soever. In contrast , 94% of t o wns pol l e d m a ke som e provi si ons for peopl e t o request th at th ei r propert y not be spray e d. Nantucket i s one t o wn th at has st art e d a program i n th e t i m e peri od bet w een th e fi rst draft GEIRand th i s draft

. The program has i n cl uded aeri a l and ground appl i cat i ons of Al t o si d, and ext e nsi v e Open M a rsh W a t e r M a nagem e nt . Act i v i t y and expense peaked i n 1992 and 1993 when th e OM W M sy st em was dug. Si nce th en th e t o wn has conduct e d sm al l am ount s of l a rvi c i d i ng i n sal t m arshes. No work i s done i n freshwat e r areas and no adulticiding is done. 3. Other Program s

a. Depart m e nt of Envi ronm ent a l M a nagem e nt The Di vi si on of Forest s and Parks di scont i nued i t s own m o squi t o control program i n 1978 at th e suggest i on of th e M E PA offi ce pendi ng th e com p l e t i on of an Envi ronm ent a l Im pact R e port of st at ewi d e m o squi t o control. From 1966-77, their m o squito control program c onsisted of adulticide treatm e nts of state parks twice each

sum m e r coi n ci di ng wi th th e heavy use peri ods of M e m o ri al Day and Jul y 4th. Appl i cat i ons were m a de wi th a m i st bl ower and a m i xture of m e thoxy chl o r (9 gal of 25% EC ), m a l a th i on (1 gal of 57% EC ) and wat e r (40 gal ) . There

was n o attem p t to ev alu a te th e effectiv eness of th ese appl i cat i ons, whi c h were presum abl y carri ed out at

ni ght

. The Essex County Mosquito Control Program adultic ides as required at the Sa lisbury Beach State Park and at the Bradley Palm er State Park in Ham ilton. b. Depart m e nt of Publ i c Heal th The Massachusetts DPH is responsible for surveillan ce for EEE Virus, risk assessm ent, public inform ation and education on EEE disease, as well as providing advice to the State Reclam ation and Mosquito Control Board on appropriate risk m a nagem e nt for EEE. DPH is also re sponsible for recom m e ndations for wide area aerial vector control interventions in the event of an EEE Public Health Em ergency. The Process for Risk Assessm ent and Managem e nt of EEE is outlined in the “Vector Control Plan to Prevent EEE” (See Appendix B, Vector Control Plan: Risk Assessm ent Section VI). Every year DPH’s Eastern Equine Encephalitis Surve illance Program (EEESP) coll ects data to assess the risk of EEE. This is an on-going program , which is carried out at the State laboratory In stitute in Jam a ica Plain. Key variables used to determ ine the risk of EEE include precipitation levels, m o squ ito population abundance, andpresence of EEE virus in m o squitoes, horses, and hum ans. The purpose of the DPH EEE surveillance effort is to assess risk and use this inform ation to advise the SRM CB and the public of the relativ e risk of EEE in any given season. In addition, the DPH chairs the Pesticide Revi ew Board, which regulates pesticide use in the state. In 1956 the EEESP was established in southeastern Ma ssachusetts by the U. S. Public Health Service (CDC), in cooperation with the Massachusetts DPH, for the study of EEE. A surveillance program has continued since 1957 to the present, with funding solely from DP H beginning in 1970. Surveillance for EEE consists of

m oni t o ri ng m o squi t o es t o det e rm i n e popul at i on l e vel s i n rel a t i on t o previ ous y ears’ l e vel s , especi al l y C s . mel anura, Ae. vexans, Ae. canadensi s , Cq . pert urbans, and Ae. so llicita n s , t e st i ng sam p l e s of m o squi t o popul at i ons for th e presence of EEE and Highland J (HJ) virus (HJ is an arbovi rus which does not cause hum an disease but which is an indicator of arboviral activity in the bird population), testing suspected EEE horse cases and screening suspected hum an cases of encephalitis, m e ningoencephalitis or other cases of clinical disease that m a y m i m i c sym p tom s of EEE virus infection. Inform ation is also com p iled on pr ecipitation, groundwater levels, and surveillance data from other sites. The surveillance program keeps abreast of new developm ents in the study of EEE and has expanded its
tr appi ng effort i n response t o th ese devel opm ent s . In recent years DPH has funded studies in collabora tion with local universities aim e d at furthering our understanding of EEE. These have included an a ssessm ent of the focality of EEE transm issions; C s . mel anura host preferences studies and research aim e d at identificati on of th e pri n ci pal avi a n reservoi r host speci es for th e

am plification and perpetuation of the EEE virus. In 1997, m o squito trapping was expanded to include several bird roost studies postulated to be critical foci for am plification of EEE virus (K om ar et al., unpublished). Each year th e EEESP p r ep ares a su m m a ry o f th e p a st seaso n ’ s su rv eillan ce activ ities in No v e m b er, an d provides an early prediction of the ne xt season with regard to the likeli hood of the presence of EEE virus in the envi ronm ent and th e pot ent i a l for tr ansm i ssi on t o hum ans based on key vari abl e s of preci pi t a t i on, m o squi t o populations and prior years’ EEE activity in m o squitoes, birds, horses and hum ans. This inform ation is provided to the SRMCB, EOEA agencies, the State Legi sl ature, B o ards of Heal th and th e general publ i c . Vect or control

m eetings are held as needed with eas t e rn M a ssachuset t s M o squi t o C ontrol Di stri ct Superi nt endent s and th e SR M C B th roughout th e season. Surveillance provides an early warn ing of the presence of EEE in the environm ent. The EEE Surveillance Program begins no later than the first week in June and continues through early October, unless a killing frost bringsth e m o squi t o season t o an end earl i e r. Thi s i s a cont i nui ng program wi th an object i v e t o provi de epi d em i o l ogi cal inform ation on EEE virus and potential vectors of this di sease to guide public health actions. EEE surveillance report s are i ssued weekl y th roughout th e tr appi ng season and provi de a sum m a ry of weekl y l aborat ory anal y s es for

m o squi t o es, horses and hum ans. W h en EEE is found in trapped m o squitoes, supplem en tal surveillance activities ar e initiated. These m a y i n cl ude i n creased tr appi ng of bri dge vect or speci es (sp ecies that transm it the dis ease from bi rds t o horses or hum ans) utilizing a variety of trapping m e thods, estim ation of vector species larval abundance, and age structure determ inations. Isolation of EEE also m a y trigger health alerts and advisories when appropriate. The fi rst em ergency effort t o control m o squi t o es duri ng a di sease out break occurred i n 1956 when $90,000

was m a de available from the governor’s em ergency fund for aerial adulticiding. In this effort 150,000 acres were sprayed with DDT. The EEE disease outbreak of 1973 led to an aerial ULV application of m a lathion in the late

sum m e r, when approxim a tely 1.7 m illion acres in eas tern Massachusetts were treated. In 1974 and 1975 approxi m a t e l y 82,000 acres were aeri a l l y tr eat ed. The cost of th e 1973-75 vect or control i n t e rvent i ons was over $700,000. In the EEE outbreak of 1982-84, no state-funde d aerial application was conducted, however, $150,000 was al l o cat ed from th e governor’s em ergency fund t o support i n t e nsi f i e d ground spray i ng. In 1990 another

em ergency aeri a l ULV m a l a th i on appl i cat i on occurred over th e southeast e rn part of M a ssachuset t s . In th i s i n t e rvent i on 524,096 acres were tr eat ed at a cost of approxi m a t e l y $800,000. Al l i n t e rvent i ons were based upon th e likelihood of mu ltiple hum an cases of EEE. W h ile the cost of EEE vector control interventions m a y appear high, the lifelong costs associated w ith just one residual case of EEE have been estim ated at $3 m illion dollars (Villari et al . 1995).

c. Federal Lands In general , st at es have no juri sdi c t i on over fe deral propert y . Any m o squi t o control act i v i t y on U. S. governm e nt propert y i n M a ssachuset t s i s onl y subject t o fe deral l a ws and not t o th e l a ws of th e com m onweal th

. Th u s , th e fo llo win g d e scrip tio n will b e b r ief an d in fo rm atio n a l o n l y.i

. Parks, m onum ent s , refuges, et c. No m o squi t o control i s carri ed out by th e U. S. Depart m e nt of Int e ri or on any governm e nt -owned l a nd i n M a ssachuset t s . The current phi l o sophy of th e U. S. Park Servi ce and U. S. Fi sh and W i l d l i f e Servi ce seem s t o be adverse toward the initiation of pest control except in unusual circum stan ces, e.g., the cam pground in Everglades Natio n a l Park , th e Islan d W ild life Refu g e , etc. Th e Cap e Co d Natio n a l Seash o r e is p e rh ap s th e U. S. Park Serv ice propert y wi th th e m o st si gni fi cant m o squi t o popul at i ons. Park Servi ce bi ol ogi st s have conduct e d th ei r own studi es on the environm ental im pact of Cape Cod m o squito control activities (Portnoy 1983, 1984a, 1984b) in adjacent
estu ari e s and have l obbi ed agai nst cert a i n di t c h cl eani ng pract i ces on envi ronm ent a l grounds. The East M i ddl esex M C P has been control l i ng m o squi t o es i n Great M eadows Nat i onal W i l d l i f e R e fuge si nce 1987. Annual aeri a l B t i appl i cat i ons t a rget ed agai nst spri ng Aedes speci es began i n 1987 and appl i cat i ons t o control Aedes vexans began i n 1990

. Prior to each application, the Ea t Middlesex MCP subm its data on preapplication larval popul ations. Following receipt of the data each year, Great Meadows National W ildlife Refuge issu es a p e rm it fo r th e aerial ap p licatio n . Th e Natio n a l Pa rk Service reservation area (P au l Rev e re's Rid e ) in East M i ddl esex C ount y has been decl ared off l i m i t s t o any m o squi t o control act i v i t y (by East M i ddl esex M C P) except for di t c h cl eani ng. The Essex C ount y M C P has com p l e t e d OM W M project s on th e Parker R i ver W i l d l i f e R e fuge. ii. Military Bases. All U. S. Military b a ses h a v e a p e st co n tro l sectio n , wh ich o f ten en g a g e in so m e m o sq u ito su rv eillan ce an d
control act i v i t y . In M a ssachuset t s , Fort Devens has rout i n el y carri ed out both l a rval and adul t control

. In th e 1980s th i s has consi s t e d of m i st bl owi ng wi th M a l a th i on for adul t control and Al t o si d bri quet t e s for l a rval control

. Hanscom Air Force Base joined the East Middlesex MC pr oject in 1985 but still assists with surveillance and som e

co n tro l activ ities. No n e o f th e o th e r m ilitary b a ses in Massach u s etts (i.e., Barn es in W e stfield , W e sto v e r in Chicopee, and Otis on the Cape) reported m o squito control activitie s in recent years. d. Private Reserves. There are several private reserves and estates in Massachusetts (e.g., Cranes Beach), which are frequently used by th e publ i c i n one capaci t y or another. There i s no i ndi cat i on th at m o squi t o control i s regul arl y pract i ced on any of th ese propert i e s. It seem s unl i k el y ; th erefore, th at th i s represent s a si gni fi cant cat egory of undocum ent e d pest i c i d e use or habi t a t m odi fi cat i on for m o squi t o control , past or present
. C e rt ai n M C Ps i n cl ude, by request , som ereserv atio n p r o p e rties in th eir o v e rall p r o g r am b u t th o s e activ ities are in clu d e d in th eir p r o g r am su m m a ries. C

. Hi st ori cal Overvi ew of M o squi t o Co n tro l Practices in Massach u s etts 1. Pract i ces pri o r t o 1980 Developm ent along the Eastern Seaboard , especially for tourism , was pred icated on an ability to control the hoards of salt m a rsh m o squitoes. The earliest experim e ntal work took place in New Jersey salt m a rshes in the late teens and early 1920' s. These successes en couraged the m a ssive hand-ditching pr ojects in East Coast m a rshes that took place during the W P A program s of the great depressi on, with som e 3,000 m iles of ditching being dug in M a ssachuset t s ’s sal t m a rshes al one. These di t c hi ng sche m e s, wh ile q u ite effectiv e in red u c in g salt m a rsh

m o squitoes, were engineered to m a ke work rath er th an for opt i mum bi ol ogi cal efficiency. Moreover, the value of
estu ari n e ecosy st em s was unrecogni zed at th e t i m e. Earl y sal t m a rsh m o squi t o control project s, such as th e one on C a pe C od i n th e 1930' s, were organi zed p r io r to th e av ailab ility o f syn th e tic p e sticid es fo llo win g W o rld W a r II an d th ese p r o j ects ex p a n d e d an d m a in tain ed
th e W P A-dug di t c h sy st em as th ei r m a i n strat e gy for m o squi t o control

. Aft e r DDT, B H C , and other organochl ori n e pesticides becam e available, they were used to both suppl em ent larval control and, for the first tim e, to conduct residual spraying for adults. Aerial application of these pesticides becam e com m onplace in the 1950' s and early 60' s. However, coastal projects that were organized afte r the introduction of these m odern pesticides still relied heavi l y on source reduct i on t o m a nage sal t m a rsh m o squi t o es . Pari s Green (an arseni cal ) and petr ol eum oi l s were developed as m o squito larvicide’s for m a laria control during W o rld W a r II and also becam e popular in the U. S. after th e war. W a ste cran k case o il was n o t in freq u e n tly u s ed in m o sq u ito co n tro l d e sp ite th e fact th at th in o ils (e.g ., diesel fuel) with a spreading agent provide for the greatest and m o st eff ective surface coverage. The com m e rcial

m o squito control oil, Flit MLO, was in troduced and widely used during the 70' s, but was taken off the m a rket in the

m i d-80’s. Arosurf-MSF, a m onom olecular surface film was av ailable for several years, starting in the m i d-80, but was t a ken off th e m a rket . It i s now (1997) bei ng retu rned t o th e m a rket as Agni que M M F (Henl e y , personal

com muni cat i on). Abat e (t em ephos), one of th e few organophosphat e s regi st ered for aquat i c use, was i n tr oduced a few y ears later and shared the larvicide m a rket with surface oils. The first new genera tion pesticide introduced for m o squito
control was th e growth regul at or Al t o si d (m ethoprene), a juveni l e horm one m i m i c. It has been wi del y used i n

m o squi t o control si nce th e m i d-l 970' s. Project s i n th e Northeast were sl ow t o swi t c h t o th i s hi ghl y sel ect i v em a t e ri al , perhaps due t o i t s del a y e d re sponse and narrow wi ndow for control

. The choi ce of whi c h l a rvi c i d e t o use i s based equal l y on effectiveness and safety to the applicator and to the environm ent. Adulticiding is often predicated on public com p laints. W eat her conditions and fi eld surveys also pl ay a rol e i n deci di ng when t o schedul e appl i cat i ons i n m o st project s. Ch em ical co n tro l in fresh water m a rsh e s fo llo wed a sim ilar p a ttern to th at in salt m a rsh e s. Treatm e n t o f
cat ch basi ns, fi rst wi th oi l s fol l o wed by organochl ori n es and organophosphat e s, dat e s back t o th e begi nni ng of m o st M a ssachuset t s project s. Ph ysical co n tro l was lim ited to d r ain a g e m a in ten a nce and expansi on i n both salt m a rshes and freshwater areas. B i ol ogi cal control was not conduct e d. C ontrol l i ng C s . mel anura larv ae in larg e wh ite ced ar/red m a ple swam ps was generally considered an im possibility so aerial adulticiding was a dopted as the strategy of choice for v ector control during epidem ic threats. Projects within the m a in fo cus of EEE in southeastern Massachusetts were the only ones to routinely do aerial spray i ng. Thi s work was gradual l y di scont i nued i n th e 1970’s due t o envi ronm ent a l concern over aeri a l ad u lticid in g . Projects have interm ittently had the support serv ice of a SMRCB entom o logi st. During 1976-81, a period when the projects had no entom o logical support from the SM RCB, an extension biting-fl y specialist was available
th rough a cooperat i v e agreem ent wi th th e Uni v ersi t y of M a ssachuset t s . Each project contri but ed 0.5% of th ei r annual operating budget as their share of support for this position, which was jointly funded by Massachusetts C ooperat i v e Ext e nsi on. The speci al i s t devel oped contro l recom m e ndat i ons, eval uat e d new control m e thods, set up a statewide light trap surveillance progr am , and carried out other s upport services to the projects. Som e controversy devel oped am ong project s, part i c ul arl y over th e control recom m e ndat i ons m a de by th e speci al i s t
. Fol l o wi ng hi s resig n a tio n , th e SMRCB ag ain h i red an en to m o lo g i st an d th e Un iv ersity p o s itio n was d i sco n tin u e d

. 2. Transi t i oni ng: from 1980 t o 1995. B y th e earl y 1980s, concerns over pest i c i d e use and we t l a nds l o ss began t o encroach on m o squi t o control

. Gri d di t c hi ng for l a rvae and m a l a th i on for adul t s was no l onger a desi rabl e one-t wo punch. C ontrol tr ends duri ng th e eig h ties an d early n i n e ties in clu d e : z Changing from traditional chem icals, such as Ab ate and Flit MLO, to Bti and m e thoprene for larval control (Table 3).z C h angi ng from m a l a th i on t o perm ethri n or resm ethri n for adul t control (Tabl e 3). z C h angi ng from open t i d al di t c hi ng t o open m a rsh wat e r m a nagem e nt for sal t m a rsh m o squi t o control

. z R e duct i on i n th e num ber of t o wns bel ongi ng t o Project s i n th e l a t e 1980s. Thi s tr end has reversed in th e p a st sev e ral years.

Tabl e 3. A com p ari s on, bet w een t h e earl y1980’s and t h e m i d-1990’s of chem i cal s used byM a ssachuset t s M C Ps. Active Ingredient Toxicity Class Used Between a 1981-1985 1993-1995 A S L A R V I C I D E S Ba cillu s th u r in g i en sis var. israelensis IV + +++ Fenthi on II - N Isooct a decanol b M a lathion III + N M e thoprene IV o ++ M e thoxy chl o r IV ++ N Mineral Oil III-IV +++ o Perm ethrin III - N Tem e phos IV + - AS ADULTICIDES Di brom II + N Fenthi on II o N Malathion III +++ - M e thoxy chl o r IV + N Perm ethrin III N ++ Resm ethrin III - +++ a +++ = Prim ary pesticide used ++ = Significant use + = C o m m on but m i nor use o = Infrequent use

- = Rarely used N = Never used b Di scont i nued product (Arosurf)

Altosid had com e onto the m a rket but acceptance wa s slow, both because it was hard to m onitor the efficacy (larvae do not die for som e tim e) and because of restrictions on the label against using in fish habitat. By
th e earl y ‘90s, however, i t was i n general use th roughout M a ssachuset t s . The ext e nded-resi dual bri quet form of Alto sid was tested ag ain s t Cq . pert urbans , as was Arosurf-M SF, but results were m i xed and the briquet’s high cost p r ev en ts it fro m b e in g an attractiv e co n tro l ag en t fo r larg e cattail areas. Trials with Alto sid p e llets wereencouragi ng but th i s control t echni que i s not bei ng used i n M a ssachuset t s . In contrast t o Al t o si d, th e bi ol ogi cal pest i c i d e Ba cillu s th u r in g i en sis var. israelensis was quickly accepted by M a ssachuset t s ’s project s when i n tr oduced i n th e earl y 80' s. It i s a m a i n st ay of m o st program s, despi t e som e problem s in salt m a rshes and aquatic habitats high in organi c m a tter. The latter problem m a y be solved by the recent (1996) i n tr oduct i on of Bacillus sphaericus, a new bi ol ogi cal pest i c i d e th at i s desi gned speci fi cal l y for Culex breedi ng i n hi gh-organi c-m a t t e r habi t a t s . Flit-MLO disappeared from the m a rket and was replacedby Golden Bear oils. Arosurf-MSF was used in

sm all am ounts for several years before it too was taken off th e m a rket. It has recently re turned to the m a rket as Agni que M M F . B oni de M o squi t o Oi l (M i n eral oi l ) i s now avai l abl e but not used. Source reduct i on

rem a in ed a m a in stay o f th e p r o j ects d u r in g th is tim e p e rio d b u t co astal co m mu n ities sh ifted away fro m d itch

m a i n t e nance t o wards open m a rsh wat e r m a nagem e nt . An em ergi ng di ffi cul t y for control program s was th e ri se i n wet basi ns m a ndat e d by st orm wat e r runoff regul at i ons. If i m properl y desi gned th ese can breed consi d erabl e

num bers of spri ng-brood and/ or sum m e r refl ood m o squi t o es. The eval uat i on of control effect i v eness by project s rem a in ed a co m b in atio n o f p u b lic co m p lain ts, ad u lt
count s, l a rval count s, and cases of hum an di sease. Al l project s m a i n t a i n ed a publ i c educat i on co m ponent and several expanded th ei r program s. Throughout this period, outside of inadequate budgets and the inability to do m o re source reduction work,
th e m a i n operat i onal probl em s voi ced by m o st project s has been th e l ack of appl i e d research support t o assi st th em i n eval uat i ng new t echnol ogy and sol v i ng cert a i n ever-c hangi ng probl em s. For exam pl e, th e cat t a i l m o squi t o , Cq

. pert urbans , is a m a jor pest and potential epidem ic vector of EEE in m o st projects but there is presently no

recom m e nded m e thod for controlling this m o squito. D. C u rrent M o squi t o C ontrol Strat e gi es i n M a ssachuset t s 1. Overvi ew C h em i cal control , i n cl udi ng Ba cillu s product s and IGR s (Tabl e 4), and source reduct i on, i n cl udi ng open

m a rsh wat e r m a nagem e nt , dom i n at e m o squi t o control i n M a ss achuset t s (Tabl e s 5 and 6). Aeri al appl i cat i ons of l a rvi c i d es have been used by several program s (Tabl e 7) and i s l i k el y t o i n crease. B i ol ogi cal control has not been

em phasi zed except t o th e ext e nt th at OM W M creat es condi t i ons under whi c h bi ol ogi cal control operat e s. Publ i c educat i on i s a m i nor com ponent of m o st program s.Salt m a rsh m o squitoes are the prim ary target of co ast a l program s, whereas i n l a nd program s t a rget spri ngbrood and sum m e r-refl ood Aedes (Tabl e s 8 and 9)

. Coquillettidea perturbans is restricted b y larv al h ab itat to areas near cat t a i l m a rshes. However, i n those areas i t s popul at i ons can be extr em el y hi gh. Vect or m o squi t o es are not th e pri m ary t a rget s of M a ssachuset t s control program s, though project s do respond to requests for aid from DPH in tim es of EEE em ergencies. C u l i s et a mel anura l a rval popul at i ons m a y be i n ci dent al l y reduced by tr eat m e nt program s th at t a rget swam p areas. East M i ddl esex M C P di d conduct tr i a l s wi th Al t o si d pel l e t s aeri a l l y appl i e d i n Apri l , 1992 for C s . mel anura control and were successful (Henl e y 1992). Thi s work has not been repeated in Massachusetts. Policy issues have revolved ar ound wetlands and water quality preser vation and endangered species. A chroni c source of di scussi on i s m o squi t o control ’ s exem pt i on from m a ny of th e st at e-l e vel wet l a nds prot ect i on act s,

m a king the Federal Section 401 W a ter Qua lity Certification Act (adm inistered at the state level) and the state and federal Endangered Speci es Act s th e pri m ary m eans of “control l i ng” source-reduct i on work. St orm wat e r runoff regulations have increased the num ber of wet basins (retention, wet detenti on) in m a ny areas, on occasion creating breedi ng habi t a t
. Engi neers and publ i c offi ci al s i nvol ved i n desi gni ng and approvi ng such basi ns have been sl ow t o acknowl e dge m o squi t o control as desi gn cri t e ri a, though th e rel e vant sect i ons of th e St orm wat e r Pol i c y Handbook and St orm wat e r Techni cal Handbook rel eased by DEP i n M a rch 1997 shoul d be i n corporat ed i n t o M C P pract i ces (see Appendi x E for l i s t i ng of rel e vant i n form at i on). The EEE outbreak in 1990 highlighted a need for st ronger DPH policies regarding em ergency m o squito
control

. As a resul t , th e M a ssachuset t s Depart m e nt of Pu b lic Health p u b lish e d “Vecto rCo n tro l Plan to Prev en t Eastern (Equine) Encephalitis” (August 7, 1991) and im plem en ted an extensive Public Education Program in 1991.Tabl e 4. Pest i c i d e use by Project , 1993 th rough 1995. Pest i c i d e C a t a gory Am ount Used 1993 1994 1995 Berk sh ire MCP Al t o si d B r i quet s IV 24.3 l b 5.8 l b 1.8 l b B act i m os Granul es IV 534.0 l b 2124.0 l b B act om os Pel l e t s IV 232.0 l b 2026.0 l b 2093.0 l b Abate 4E III 0.6 gal Arosurf-M SF III 16.0 gal 5.0 gal Scourge 18+54 III 10.1 gal 25.0 gal 20.1 gal B r i s t o l C ount y M C P Al t o si d B r i quet s IV 0.57 l b 45.6 l b B act om os Pel l e t s IV 1593.0 l b 80.2 l b 2300.5 l b Scourge 12+36 III 151.9 gal 190.6 gal 173.4 gal C a pe C od M C P Alto sid Briq u e ts a IV 9.5 l b 8.4 l b 11.0 l b B act om os Pel l e t s IV 20,710.0 l b 41,497.0 l b 43,174.0 l b GB 1111 III 671.0 gal 704.0 gal 330.0 gal a Tot a l s report e d as bri quet s covert ed t o l b s C e ntral M a ssachuset t s M C P Al t o si d B r i quet s IV 231.9 l b 192.7 l b 106.2 l b B act i m os Granul es IV 281.1 l b 115.9 l b 2829.1 l b B act om os Pel l e t s IV 1223.0 l b 3313.0 l b 81.0 l b Vect obac Granul es IV 96.9 l b Vect obac 12AS IV 225.7 gal 171.7 gal W i t c o GB-1356 III 65.1 gal 95.2 gal 5.6 gal W i t c o GB-1111 III 23. 5 gal Scourge 18 + 54 III 342.6 gal 398.5 gal 388.5 gal a Dry and l i qui d ounces as report e d covert ed t o pounds or gal l ons respect i v el y East Middlesex MCP Acrobe IV 125.0 gal Al t o si d Pel l e t s IV 15.0 l b 10.9 l b Alto sid Briq u e ts b IV 69.9 l b 20.7 l b 33.7 l b Alto sid XR Briq u e ts b IV 17.1 l b Arosurf M SF III 2.3 gal 3.0 gal B act i m os Granul es IV 12,880.0 l b 6,785.0 l b B act i m os Pel l e t s IV 2,324.0 l b Vect obac G IV 8,062.0 l b 720.0 l b Vect obac 12AS IV 8.4 gal 22.9 gal 169.2 gal Perm anone 10EC III 2.4 gal 2.1 gal 1.7 gal Scourge 18 + 54 III 20.2 gal 26.0 gal 18.1 gal a Dry and l i qui d ounces as report e d covert ed t o pounds or gal l ons respect i v el yTabl e 4. Pest i c i d e use by Project , 1993 th rough 1995 (cont i nued). Pest i c i d e C a t a gory Am ount Used 1993 1994 1995

Essex C ount y M C P Alto sid Pellets IV 7 0

. 5 lb B act i m os Granul es IV 3.8 l b 252.2 l b B act om os Pel l e t s IV 1993.1 l b 4439.6 l b 887.5 l b Perm anone 31-66 a III 39.0 gal 42.5 gal 12.8 gal Scourge 18 + 54 a III 10.1 gal 25.0 gal 20.1 gal a Ounces as report e d convert ed t o gal l ons
Norfol k C ount y M C P Al t o si d XRB r i quet s IV 0.1 l b b 2.8 l b 254.8 l b B act i m os B r i quet s IV 0.6 l b 1.8 l b 48.8 l b Vect obac 12AS IV 79.0 gal 2.6 gal Vect obac AS IV 52.3 gal Arosurf-M SF III 406.7 gal 83.1 gal 149.0 gal Scourge 18 + 54 III 45.8 gal 53.2 gal 52.7 gal a R ounded t o th e nearest t e nth from report e d val u es b R e port e d val u e = 0.038 l b Pl y m outh C ount y M C P, Ground-appl i cat i on Pest i c i d e Use a Al t o si d XRB r i quet s IV 17.5 l b B act i m os Pel l e t s IV 357.0 l b 500.0 l b 50.0 l b B act om os B r i quet s IV 1.8 l b b 10.3 l b b 17.2 l b Vect obac 12AS IV 17.5 gal 2.5 gal Teknar HP-D IV 17.5 gal 20.0 gal Scourge 18 + 54 III 110.0 gal 85.0 gal 70.0 gal a See Tabl e 7, Aeri al Appl i cat i on of Pest i c i d es fo r in fo rm atio n reg a rd in g aerial ap p licatio n s . b Tot a l report e d as bri quet s convert ed t o l b s. Suffol k C ount y M C P, Ground-appl i cat i on Pest i c i d e Use a Alto sid Briq u e ts a IV 3.5 l b 4.8 l b 3.3 l b Alto sid XR Briq u e ts a IV 57.5 l b 0.1 l b 11.4 l b B act i m os Pel l e t s IV 25.8 l b 31.0 l b Vectobac 12AS b IV 3.9 gal 7.9 gal 5.1 gal Malath io n 8 E C b III 1.5 gal 1.9 gal 0.2 gal Perm anone 10EC b III 0.1 gal 1.4 gal 0.8 gal Resm eth r in c III 11.2 gal Scourge 18 + 54 b III 6.3 gal 12.1 gal 3.5 gal a Tot a l s report e d as bri quet s convert ed t o l b s. b R ounded t o th e nearest t e nth from report e d val u es. c EPA reg #4-339-53853Tabl e 5. Project di stri but i on of operat i ons by control m e thod as expressed as a percent a ge of th e budget al l o cat ed (average for 1981-1985) or as a percent a ge of th e project ’s operat i ons (1994 and 1995). Berk sh ire MCP % of B udget % of Operat i ons 1981-1985 1994 1995 Source reduct i on (excl udi ng OM W M ) 20 20 S Open M a rsh W a t e r M a nagem e nt 0 0

o u r c e r e d u c t i on 3 3 ⎨ B i ol ogi cal l a rvi c i d i ng (B t i ) 5 40 40 C h em i cal l a rvi c i d i ng/ pupi ci di ng(excl udi ng IGR s ) 0 0 C IGRl a rvi c i d i ng (m ethoprene) 5 10

h em i cal l a rvi c i d i ng/ pupi ci di ng 5 0 ⎨ Ad u lticid in g 1 0 3 0 2 0 Publ i c Educat i on 2 5 10

B r i s t o l C ount y M C P % of B udget % of Operat i ons 1981-1985 1994 1995 Source reduct i on (excl udi ng OM W M ) 75 78 S Open M a rsh W a t e r M a nagem e nt 0 0

o u r c e r e d u c t i on 6 0 ⎨ B i ol ogi cal l a rvi c i d i ng (B t i ) 6 2 2 C h em i cal l a rvi c i d i ng/ pupi ci di ng 3 ⎨ h em i cal l a rvi c i d i ng/ pupi ci di ng(excl udi ng IGR s ) 0 0 C IGRl a rvi c i d i ng (m ethoprene) 0 0 Ad u lticid in g 3 0 2 2 1 9 Publ i c Educat i on 1 1 1

C a pe C od M C P % of B udget % of Operat i ons 1981-1985 1994 1995 Source reduct i on (excl udi ng OM W M ) Inform at i on S Open M a rsh W a t e r M a nagem e nt

o u r c e r e d u c t i on 7 0 ⎨ B i ol ogi cal l a rvi c i d i ng (B t i ) 21 not C h em i cal l a rvi c i d i ng/ pupi ci di ng(excl udi ng IGR s ) C IGRl a rvi c i d i ng (m ethoprene) Suppl i e d

h em i cal l a rvi c i d i ng/ pupi ci di ng 4 ⎨ Ad u lticid in g 0 Publ i c Educat i on 5

C e ntral M a ssachuset t s M C P % of B udget % of Operat i ons 1981-1985 1994 1995 Source reduct i on (excl udi ng OM W M ) 40 40 S Open M a rsh W a t e r M a nagem e nt 0 0

o u r c e r e d u c t i on 7 0 ⎨ B i ol ogi cal l a rvi c i d i ng (B t i ) 5 25 25 C h em i cal l a rvi c i d i ng/ pupi ci di ng(excl udi ng IGR s ) 5 5 C IGRl a rvi c i d i ng (m ethoprene) 5 5

h em i cal l a rvi c i d i ng/ pupi ci di ng 5 ⎨ Ad u lticid in g 1 5 1 5 1 5 Publ i c Educat i on 5 10 10Tabl e 5. Project di stri but i on of operat i ons by control m e thod as expressed as a percent a ge of th e budget al l o cat ed (average for 1981-1985) or as a percent a ge of th e project ’s operat i ons (1994 and 1995) (cont i nued). East Middlesex MCP % of B udget % of Operat i ons 1981-1985 1994 1995 Source reduct i on (excl udi ng OM W M ) 26 42 S Open M a rsh W a t e r M a nagem e nt 0 0

o u r c e r e d u c t i on 3 4 ⎨ B i ol ogi cal l a rvi c i d i ng (B t i ) 28 44 37 C h em i cal l a rvi c i d i ng/ pupi ci di ng(excl udi ng IGR s ) <1 0 C IGRl a rvi c i d i ng (m ethoprene) 4 4

h em i cal l a rvi c i d i ng/ pupi ci di ng 2 7 ⎨ Ad u lticid in g 1 0 2 5 1 6 Publ i c Educat i on 1 1 1

Essex C ount y M C P % of B udget % of Operat i ons 1981-1985 a 1994 1995 Source reduct i on (excl udi ng OM W M ) 20 15 S Open M a rsh W a t e r M a nagem e nt 29 28

o u r c e r e d u c t i on - - ⎨ B i ol ogi cal l a rvi c i d i ng (B t i ) -- 40 50 C h em i cal l a rvi c i d i ng/ pupi ci di ng - - ⎨ h em i cal l a rvi c i d i ng/ pupi ci di ng(excl udi ng IGR s ) 0 0 C IGRl a rvi c i d i ng (m ethoprene) 0 1 Ad u lticid in g -- 1 0 5 Publ i c Educat i on -- 1 1
a No response
Norfol k C ount y M C P % of B udget % of Operat i ons 1981-1985 1994 1995 Source reduct i on (excl udi ng OM W M ) 50 50 S Open M a rsh W a t e r M a nagem e nt 0 0

o u r c e r e d u c t i on 5 4 ⎨ B i ol ogi cal l a rvi c i d i ng (B t i ) 4 25 20 C h em i cal l a rvi c i d i ng/ pupi ci di ng 1 3 ⎨ h em i cal l a rvi c i d i ng/ pupi ci di ng(excl udi ng IGR s ) 0 0 C IGRl a rvi c i d i ng (m ethoprene) 14 20 Ad u lticid in g 2 5 1 0 8 Publ i c Educat i on 4 1 2
Pl y m outh C ount y M C P % of B udget % of Operat i ons 1981-1985 1994 1995 S o u r c e r e d u c t i on 2 5 ⎨ o u r c e r e d u c t i on (excl udi ng OM W M ) 45 53.0 S Open M a rsh W a t e r M a nagem e nt 0 0.0 B i ol ogi cal l a rvi c i d i ng (B t i ) 5 30 25.5 C h em i cal l a rvi c i d i ng/ pupi ci di ng(excl udi ng IGR s ) 0 0.0 C IGRl a rvi c i d i ng (m ethoprene) 0 0.5

h em i cal l a rvi c i d i ng/ pupi ci di ng 2 5 ⎨ Ad u lticid in g 4 0 2 0 1 6

. 0 Publ i c Educat i on 5 5 5.0

Tabl e 5. Project di stri but i on of operat i ons by control m e thod as expressed as a percent a ge of th e budget al l o cat ed (average for 1981-1985) or as a percent a ge of th e project ’s operat i ons (1994 and 1995) (cont i nued).Suffol k C ount y M C P % of B udget % of Operat i ons 1981-1985 1994 1995 Source reduct i on (excl udi ng OM W M ) 5 5 S Open M a rsh W a t e r M a nagem e nt 0 0

o u r c e r e d u c t i on 1 ⎨ B i ol ogi cal l a rvi c i d i ng (B t i ) 26 30 30 C h em i cal l a rvi c i d i ng/ pupi ci di ng 2 5 ⎨ h em i cal l a rvi c i d i ng/ pupi ci di ng(excl udi ng IGR s ) 0 0 C IGRl a rvi c i d i ng (m ethoprene) 15 15 Ad u lticid in g 4 6 4 0 4 0 Publ i c Educat i on 2 10 10

Tabl e 6. Ty pes of C ontrol Act i v i t y , 1 b y Hab itat Salt Marsh Sp rin g Su m m e r Cattail B r ood R e -Fl ood B e rkshi r e C ount y C , F C , F B r i s t o l C ount y A C C F Cape Cod M C P A,C,D,E A,C,D,E A,C,D,E A,C,D,E Central M a ssachusetts A,C,E,F A,C,D,E,F A,C,D,E,F East M i ddlesex A,C,D A,C,D Essex B,C A,C A,C Norfolk A,C,D,F A,C,F A,C,D,F F Plym outh A,C,D,F A,C,F A,C,F F Suffolk C,D,F A,C,D,F A,C,D,F F 1 Types of control activities -- indicate the types of control activities carried out on each wetland type using the

fol l o wi ng cat egori e s: A -- Source reduct i on B -- OM W M C -- B i ol ogi cal l a rvi c i d i ng D -- IGR larviciding E -- Larviciding, non-IGRs F -- Ad u lticid in gTabl e 7. Aeri al appl i cat i on of Pest i c i d es, 1993 th rough 1995 Project /T own Dat e s Ti m e of day Ac reage Pesticide Rate Target Area 1993 East Longm eadow 4/ 26 - 5/ 12 Day l i ght 1,000 Vect obac 12AS 1 qt / acre E. M i ddl esex M C P Apri l 12-22 6 AM - 8 PM 2,017 Vect obac G 1 pt / acre Bactim o s Pellets 5 - 7

. 5 lb /acre Pl y m outh M C P a Apri l 12-16 4 AM -Noon 1,360 Vect obac 12AS 1 pt / acre Spri ng B r ood M a y 3-7 4 AM - Noon 1,400 Vect obac 12AS 1 pt / acre Spri ng B r ood M a y 10-14 4 AM - 9 AM 1,920 Vect obac 12AS 1 pt / acre Spri ng B r ood 1994 C h el m s ford Apri l 16-22 Dawn - 11 AM 700 B act om i s Granul es 5 - 7.5 l b / ac East Longm eadow M a y 5 - 12 Day l i ght 1,000 Vect obac 12AS 1 pt / acre E. M i ddl esex M C P Apri l 19-28 6 AM - 8 PM 2,700 Vect obac G 5 - 7.5 l b / ac W e t l a nds B act i m os Granul es 5 - 7.5 l b / ac August 23-27 6 AM - 8 PM 1,000 Vect obac 12 AS 1 pt / acre Fl ood Pl ai n/ W e tlan d Acrobe 1 pt / acre Pl y m outh M C P a Apri l 18-22 4 AM - 9 AM 8,000 B act i m os Pel l e t s 8 l b / acre Spri ng B r ood Apri l 25-29 4 AM - 9 AM 16,000 B act i m os Pel l e t s 8 l b / acre Spri ng B r ood M a y 2-6 4 AM - Noon 8,000 Teknar HP-D 1 pt / acre Spri ng B r ood 1995 C h el m s ford Apri l 16-22 Dawn - 11 AM 700 B act om i s Granul es 5 - 7.5 l b / ac East Longm eadow M a y 5 - 12 Day l i ght 1,000 Vect obac 12AS 1 pt / acre E. M i ddl esex M C P Apri l 12-22 6 AM - 8 PM 2,800 Vect obac 12 AS 1 pt / acre Bactim os Granules 5 lb/acre Essex M C P June 10-17 5 AM - Noon 1,400 Vect obac 12AS 1 qt / acre Sal t M a rsh June 20-24 5 AM - Noon 1,000 Vect obac 12AS 1 qt / acre Sal t M a rsh Jul y 8-22 5 AM - 8: 30 PM 1,000 Vect obac 12AS 1 qt / acre Sal t M a rsh August 5-19 5 AM - 8: 30 PM 1,400 Vect obac 12AS 1 qt / acre Sal t M a rsh Pl y m outh M C P Apri l 10-14 4 AM - Noon 11,000 Teknar/Acrobe 1 pt / acre Spri ng B r ood Apri l 18-21 4 AM - Noon 11,000 Teknar/Acrobe 1 pt / acre Spri ng B r ood Apri l 24-28 4 AM - Noon 11,000 Teknar/Acrobe 1 pt / acre Spri ng B r ood M a y 1-5 4 AM - Noon 11,000 Teknar/Acrobe 1 pt / acre Spri ng B r ood M a y 8-12 4 AM - Noon 5,500 Teknar/Acrobe 1 pt / acre Spri ng B r ood
a These are actual tr eat m e nt s for Pl y m outh C ount y . Form s fi l e d wi th SR M C B were for m o re dat e s and l a rger areas than actually treated.Tab l e 8

. Estim ated wetlan d s acreag e affected , b y h ab itat, ex clu s iv e o f ad u lticid in g . Salt Marsh Sp rin g Su m m e r Cattail B r ood aR e -Fl ood a B e rkshi r e C ount y 0 500 250 0 B r i s t o l C ount y — no fi gures gi ven C a pe C od M C P — no fi gures gi ven C e ntral M a ssachuset t s 0 10,000 5,000 t o 10,000 2,000 East M i ddl esex 0 2,767 1,192 0 Essex 5,000 500 1,000 0 Norfol k 38 1,087 523 0 Pl y m outh 100 7,860 1,000 0 Suffol k 240 130 130 5 TOTAL 5,378 22,844 9,095 2,005
a There i s overl ap bet w een acreage affect ed by spri ng brood and sum m e r re-fl ood

Table 9. Percentage of control effort, from m onitoring through adultic iding (includes s ource reduction), by breedi ng habi t a t by Project

. Hab itat % Effo rt

_______________ 1994 1995 Speci es t a rget ed Berk sh ire MCP Sal t m a rsh 0 0 Freshwater Spri ng re-fl ood 90 90 spri ng brood Aedes Sum m e r re-fl ood 10 10 Ae. vexans Cq . pert urbans 0 0 B r i s t o l C ount y M C P Sal t m a rsh 50 50 Ae. so llicita n s , Ae. ca n t a t o r Freshwater Spri ng re-fl ood 30 40 Ae. canadensis, Ae. excrucians, Ae. cinereus Sum m e r re-fl ood 15 10 Ae. vexans Cq . pert urbans 5 0 C a pe C od M C P Sal t m a rsh 50 50 Freshwater Spri ng re-fl ood 50 50 Sum m e r re-fl ood 0 0 Cq . pert urbans 0 0Table 9. Percentage of control effort, from m onitoring through adultic iding (includes s ource reduction), by breedi ng habi t a t by Project (cont i nued). Hab itat % Effo rt

_______________ 1994 1995 Speci es t a rget ed C e ntral M ssachuset t s M C P Sal t m a rsh 0 0 Freshwater Spri ng re-fl ood 40 40 Ae. absrratus, Ae. excrucians Sum m e r re-fl ood 30 20 Ae.vexans, Ae. canadensi s Cq . pert urbans 30 40 East Middlesex MCP Sal t m a rsh 0 0 Freshwater Spri ng re-fl ood 45 52 Ae. abserrat u s, Ae. auri f

e r, Ae. canadensi s Ae. cinereus, Ae. excrucians Sum m e r re-fl ood 37 28 Ae. vexa n s , Ae. trivitta tu s Cq . pert urbans 13 14 Essex C ount y M C P Sal t m a rsh 50 60 Ae. so llicita n s Freshwater Spri ng re-fl ood 5 5 spri ng brood Aedes Sum m e r re-fl ood 45 35 Aedes species Cq . pert urbans 0 0 Norfol k C ount y M C P Sal t m a rsh 10 10 Ae. so llicita n s , Ae. ca n t a t o r Freshwater Spri ng re-fl ood 60 60 Ae. excrucians, Ae. abserratus, Ae. cinereus Ae. canadensis, Ae. vexans Sum m e r re-fl ood 15 15 Cq . pert urbans 15 15 Pl y m outh C ount y M C P Sal t m a rsh 20 20 Ae. so llicita n s , Ae. ca n t a t o r Freshwater Spri ng re-fl ood 60 60 Ae. excrucians, Ae. abserratus Sum m e r re-flood a10 10 Ae. vexans, Ae. ci nereus, Ae. canadensi s Cq . pert urbans a10 10 a 1994 and 1995 were extr em el y dry y ears whi c h resul t e d i n l o wer th an norm a l control effort s t o ward sum m e r refl ood and Cq . pert urbans

.Table 9. Percentage of control effort, from m onitoring through adultic iding (includes s ource reduction), by breedi ng habi t a t by Project (cont i nued). Hab itat % Effo rt

_______________ 1994 1995 Speci es t a rget ed Suffol k C ount y M C P Sal t m a rsh 30 30 Ae. so llicita n s , Ae. ca n t a t o r Freshwater Spri ng re-fl ood 22 22 Ae. excrucians, Ae. abserratus, Ae. canadensis Sum m e r re-fl ood 42 42 Ae. ci nereus, Ae. vexans Cq . pert urbans 6 6

2. Current Practice

a. Salt m a rsh Mo sq u ito es The com b i n at i on of l a rge, affl uent hum an popul at i on (both perm anent resi dent s and vi si t o rs) and prol i f i c pest m o squi t o popul at i ons near M a ssachuset t s coast a l m arshes suggest s th at th e publ i c m a y al way s dem a nd control program s t o deal wi th th i s i n t e nse annoy ance probl em . M o st sal t m a rshes th at breed Aedes m o squitoes are now under m a nagem e nt and, i n m o st cases, th e strat e gy i s source reduct i on. Open M a rsh W a t e r M a nagem e nt (OM W M ) project s now underway i n Essex, Norfol k and Pl y m outh
count i e s are bei ng expanded t o i n cl ude essent i a l l y al l probl em m a rshes i n those count i e s. OM W M pl ans are developed and tailored to the specific circum stances of each individual estuar y. The perm itting and review process fo r th ese p r o j ects is tim e co n s u m in g . Th u s , it will b e so m e tim e b e fo re all m a rsh m a n a g e m e n t will co n s ist o f th is strategy even though it is currently th e m o st environm entally sensitive and rational m a rsh m a nagem e nt strategy for

mo s t si tu at i ons. Publ i c and St at e agency support for OM W M i s sol i d . W o l f e’s (1996) revi ew art i c l e on th e effect s of OMW M provides a strong basis fo r accepting OMW M as the best salt m a rsh m o squito control technique

cu rren tly av ailab l e. W o lfe m a k e s th e in terestin g p o i n t that salt m a rsh m o squitoes are an increasing problem not because they are breeding in greater num bers than before, but because m o re people are choosing to live near the
coast. Reg a rd less o f th e b e n e fits o f OMW M , m a in tain in g g r id d itch n e two r k s is still an im p o r tan t p a rt o f co astal program s. Gri d di t c hes are aesth et i cal l y unat tr act i v e and som e have cl earl y had som e negat i v e i m pact on th enorm a l hi gh sal t m a rsh ecosy st em . In contrast , evi d ence suggest s th at som e di t c hed m a rsh m a y be m o re product i v e than unditched m a rshes (Shisler & J obbins 1975). No qualitative studies on the im pacts of grid ditching in M a ssachuset t s have been done but cl earl y th e habi t a t has been dram at i cal l y changed. C onvert i ng open sy st em s t o OMW M system s does create a m o re-natur e, though still highly m a naged, system

. In the interim , current ditch cleaning practice seem s preferable to the increased use of larvicides. There are cert a i n sal t m a rshes where ol d di t c hes are effect i v el y control l i ng m o squi t o product i on and perhaps where new OMW M activities m i ght actually disrupt the m a rsh m o re than m a intaining the status quo. Thus, OM W M pl ans shoul d not be aut o m a t i cal l y prescri b ed for every sal t m a rsh wi thout fi rst exam i n i ng th i s i ssue. Larviciding is still carried out in salt m a rshes th at are unditched or in which ditches are ineffective or

unm ai nt ai ned. Larvi c i d es i n current use i n cl ude th e bi ol ogi cal pest i c i d e B t i , th e i n sect growth regul at or Al t o si d, and surface oils. These are all pesticides that have lower ri sks associated with their use. Bti and Altosid have the least potential non-target effects because of their high selectivity for certain dipter ous insects. Bti is not always as effect i v e i n hi ghl y organi c sal t m a rshes as i t i s i n other habi t a t s . Adulticiding in coastal areas is of ten necessary because of the huge num bers of m o squitoes that breed on the m a rsh (a 99% kill with larvicide can still leave a lot of m o squitoes). Truck-m ounted ULV application is the
st andard response, as i s th e case for fresh wat e r adul t m o squi t o es di scussed bel o w. b. Inl a nd Freshwat er W e t l a nds M o st project s do a consi d erabl e am ount of source reduct i on work i n freshwat e r wet l a nds. Thi s act i v i t y consi s t s pri m ari l y of di t c h and cul v ert cl eani ng t o di scourage pondi ng al ong natu ral wat e rway s and th e resul t a nt product i on of spri ng and refl ood Aedes. R out i n e m a i n t e nance general l y i nvol ves hand-cl eani ng of debri s from drai nage sy st em s and brush rem oval where i t i s encroachi ng on the flow system . Machiner y i s not used for rout i n e

m a i n t e nance but i s used where det e ri orat i ng condi t i ons (a bui l d -up of such sedi m e nt s as road sand bei ng a com m on

exam pl e) requi re work th at cannot be done by hand. Larvi c i d i ng i s done wi th B t i product s , Al t o si d or Gol d en B ear oi l

. The vast m a jori t y of l a rvi c i d i ng i s done aft e r m o squi t o breedi ng has been docum ent e d. M o st appl i cat i ons are m a de from th e ground by backpack spray e r or by hand (bri quet s ). Aeri al appl i cat i ons t o freshwat e r areas are lim ited , b u t in creasin g (Tab le 7 ) . Pre-h a tch wo rk is done by several project s. In general th e area mu st have a l e ngthy hi st ory of m o squi t o breedi ng. Mosquito breeding in vernal pools, large acid sw am ps, and cattail/water willow ponds cannot be readilycontrol l e d by source reduct i on work. Even l a rvi c i d i ng i s oft e n di ffi cul t i n l a rge or deep perm anent swam ps. Pro j ects with a larg e acreag e o f th ese h ab itats (i.e., No rfo lk , Plym o u th an d Bristo l) still d e p e n d m o re o n ad u lticid in g than do projects whose larval sources are m o re accessible to larviciding. Helicopter application of granular larvicides is perhaps the only way to reach m a ny of these habitats with larvicides, but this practice has been ham p ered in the past by the fact that fl i ght pl ans had t o be fi l e d t oo far i n advance. Thi s probl em was overcom e by
th e East M i ddl esex M C P by fi l i ng th e fl i ght pl an when fl oodi ng st art e d, not when l a rvae were fi rst seen. Thi s carried th e risk o f req u e stin g a treatm e n t th at tu rn ed o u t to b e u n n ecessary b u t th e p r ed ictab ility o f Ae. vexans breedi ng aft e r fl oodi ng i s hi gh. R e gardl e ss, changes m a de t o th e Pest i c i d e B o ard regul at i ons at th e st art of 1997
season t o m a ke i t easi e r t o conduct aeri a l work. Norfol k M C P i s act i v el y i n creasi ng i t s aeri a l appl i cat i on program . Coquillettidea perturbans rem a i n s a probl em for l a rval control

. Sl ow-rel ease Al t o si d formul at i ons l ooked prom i s i ng for th e control of cat t a i l m o squi t o es (W al ker 1987) but th i s t echni que i s not bei ng used t oday , m o st l i k el y because of high cost. Altosid pellets ha ve been used with som e effect (Ran ta et al. 1994) and this approach m a y

m a ke expandi ng Cq . pert urbans l a rval control possi bl e. Fortunat e l y , th i s m o squi t o has not been a si gni fi cant pest over the last several years in m o st projects (see Table 9 for low % of effort directed towards Cq . pert urbans ). In East Middlesex MCP, however, Cq . pert urbans has continued to greatly exceed nui sance threshold levels, being the

m a in n u i san ce sp ecies b e tween m i d

- Ju n e an d m i d

- Ju ly. In n i n e cities an d to wn s o f th e East Mid d l esex MCP, th ere i s at l east one l i ght tr ap si t e whi c h annual l y records great er th an 500 Cq . pert urbans per ni ght duri ng th e peak peri od for th at speci es. Dry th e dry sum m e rs of 1993, 1995, and 1997, Cq . pert urbans has been th e onl y si gni fi cant

m i d-sum m e r m o squi t o probl em . No source reduction program s are in place for the m a ple/cedar swam ps in which C s . mel anura breeds. Larvi c i d i ng th ese areas has had som e success (Henl e y 1992, W oodrow et al . 1995). No control program s t a rget perm anent

- wat e r breedi ng Culex or Anophel e s except in cases where Aedes are breedi ng as wel l and i n urban habi t a t s (see bel o w). W i th th e except i on of m i nor work wi th dum ped t i r es, Ae. triseria tu s is not targeted for control. Freshwater wetlands have been the sites m o st likely to have control restri ct i ons due t o endangered speci es. Sal a m a nders, tu rt l e s and dragonfl i e s have al l been ci t e d as reasons t o ei th er forego work or t o restri ct l a rvi c i d e choi ce. In at l east one case, th e exi s t e nce of vernal pool s al one, regardl e ss of endangered speci es presence, was sufficient for the local conservation com m i ssion to h a lt d r ain a g e m a in ten a n ce in th e area.c. Irri gat e d and Other M a n-M a de Refl ood Habi t a t s Very little ag ricu ltu ral lan d in Massach u s etts is irrig a ted

. Th o s e lan d s wh ich are irrig a ted ten d to h a v e sandy soi l s wi th good percol at i ng charact eri s t i c s. Gol f c ourses, athl et i c fi el ds, et c., whi c h t e m porari l y fl ood and produce refl ood Aedes are generally very accessible and larvicidlng is the com m on practice for dealing with the habitats. Source reduction is occasionally used to elim in ate or lim it breeding in these poorly graded and drained grassy habi t a t s . d. Urban Habi t a t s M o st project s do both source reduct i on (cl eani ng and repai r i ng) and l a rvi c i d i ng work on st orm drai n cat ch basi ns t o control Cu lex breedi ng. Sl ow rel ease l a rvi c i d e formul at i ons are popul ar i n th ese sm al l encl osed habi t a t s . Thi s urban m o squi t o control act i v i t y i s non-controversi a l

. It i s effect i v e, but th e real i m pact of th ese m o squi t o es on bi t i ng annoy ance i s not cl ear (see Part IV). W e t basi ns have em erged as a pri m ary probl em i n ar eas of new devel opm ent
. Shal l o w-wat e r basi ns oft e n hol d wat e r l ong enough i n th e spri ng t o breed Ae. canadensi s . B a si ns th at have deep wat e r i n th e spri ng (one-pl u s feet ) m a y not breed m o squi t o es th en but m a y dry down i n Jul y and be perfect Ae. vexans breeding sites after a heavy August rai n . B a si ns th at are deep al l y ear round m a y have i nvasi ve cat t a i l on whi c h Cq . pert urbans can d e v e lo p . On ly b a sin s th at h o l d water fo r a week o rless, ev en d u r in g th e wet sp rin g m o n th s , will p r o b ab l y n o t produce m o squitoes and even these requi re m a in ten a n ce to av o i d wetlan d s typ e v e g e tativ e g r o w th th at ev en tu ally causes l onger pool i ng. Two other probl em s wi th basi ns i s th at m a ny are fenced off, so th at th ey are di ffi cul t t o

m oni t o r, and ownershi p i s oft e n hazy so th at m a i n t e nance l a pses. Prevent i on of m o squi t o breedi ng i n basi ns mu st becom e a desi gn consi d erat i on. 3

. Cu rren t Po licies

a. R e quest s for C ontrol R e quest s for control are al m o st i nvari abl y for adul t m o squi t o control , though i ndi vi dual s m a y request th at wetlands on or adj acent to their property be checked and larvicided. Requests for a dulticiding are handled in vary i ng way s by th e project s (Tabl e 10). In m o st proj ects, com p laint calls are c onsi d ered a val i d form of det e rm i n i ng spray schedul es, i f not on an i m m e di at e basi s, cert a i n l y over th e l ong t e rm . R e spondi ng rapi dl y t o

co m p lain t calls is co n s id ered a p r im ary o b j ectiv e o f m a n y projects, as they are servi ce organi zat i ons. Of course,
th ei r servi ce i s t o th e com m on publ i c good, and i ndi vi dual request s shoul d be judged on th at basi s. W h ether al lprogram s do so i s not known.

Tab l e 1 0

. Ad u lt Mo sq u ito es: Mo n ito rin g an d Ad u lticid in g Po licies Tech n i q u e s u s ed to trig g e r ad u lticid in g Project Li ght Traps Landi ng C ount C o m p l a i n t C a l l s Post -treat m e nt M oni t o r Berkshire No No Yes (for local treat a ) Red u c tio n in calls Berkshire also stated that adulticiding is done on a pre-scheduled basis B r i s t o l C ount y Not for Spray No Yes R e duct i on i n cal l s R e duct i on i n l i ght tr aps Cape Cod Yes, but no Adultic iding is done by Cape Cod C e ntral M a ss Yes 3/m i n Do l a ndi ng count R a ndom re-checks East Middlesex 100 hum an-biting 4/m i n (for lo cal treat) Supplem ent LT data Not done Essex No 10+/m i n 5/ square m i l e Landi ng count s Norfol k Yes 2/m i n (for l o cal tr eat ) Yes (for l o cal tr eat ) Li m i t e d l a ndi ng count s Red u c tio n in calls Pl y m outh No Inform al Yes St aff observat i ons R e port s from resi dent s Suffol k Yes Yes Do l a ndi ng count Inform al checks
a Local tr eat m e nt by hand-hel d or backpack spray e r onl y

Larvi c i d i ng request s do not m a ke up th e m a jori t y of cal l s t o M C Ps. B u t , for exam pl e, East M i ddl esex MCP does receive calls for both larval c ontrol and inform ation on how residents can control m o squitoes. In general these com e as a result of their newspaper releases con cerni ng l a rvi c i d i ng or from resi dent s who observe control crews in wetlands in the past (Henley, personal com munica tion). Other program s m o st likely receive sim ilar calls. In general , though, m oni t o ri ng i s based on hi st ori cal knowl e dge and survey work by th e M C P i t s el f. W h en l a rvae are found, l a rvi c i d i ng t y pi cal l y occurs. Pre-hat c h work, i s an except i on t o th e rul e th at l a

rvae mu st be present and i s conduct e d when th e project superi nt endent feel s th ere i s suffi ci ent hi st ori cal dat at o just i f y appl i cat i ons pri o r t o l a rval hat c h. b. Docum e nt at i on for C ontrol Im pl em ent a t i onAl l Project s keep records of com p l a i n t cal l s , m o st conduct l i ght tr appi ng and m o st conduct som e l a ndi ng counts (Table 10). Of the three, landing counts are the m o st casual, often being little m o re than a report that there are a l o t of m o squi t o es bi t i ng th e fi el d st aff i n a cert a i n area. However, B e rkshi r e C ount y , C e ntral M a ss and Suffol k investigate each com p laint call and take landing-count data. Fi el d workers record l a rval count s at th e si t e s th ey vi si t
. In som e cases, th ey bri ng l a rvae back ei th er for larv al id en tificatio n o rfo r rearin g to ad u lts fo r ID. In m a ny cases, the larvae are sight-IDed to genus and m o re speci fi c i d ent i f i cat i on i s not done. C ount s for aeri a l appl i cat i on and/ or OM W M are mu ch m o re det a i l e d and general l y i nvol ve t a ki ng a speci fi c num ber of di ps at a perm anent l y si tu at ed sam p l i ng st at i on. An area that needs im provem e nt is record keepi ng regardi ng aeri a l appl i cat i ons of l a rvi c i d e. The general pl ans fi l e d by project s wi th th e st at e are not speci fi c enough, as th ey t e nd t o descri be th e m a xi mu m possi bl e application acreage, rather than acreag e actually treated. Projects do keep r ecords of actual treatm e nts and these shoul d be fi l e d wi th th e st at e as a post

- tr eat m e nt report , R ecord keepi ng for freshwat e r drai nage m a i n t e nance i s spot t y and needs i m provem e nt . W i thout basel i n e d a ta o n ch an n e l cro ss-sectio n s , it is im p o ssib l e to m o n ito r m a in ten a n ce wo rk to en su re th at ch an n e ls are n o t becom i ng larger.

c. Sel ect i on of C ontrol Strat e gi es C ontrol strat e gi es m a y be sel ect ed at th e project l e vel for both short

- and l ong-t e rm work, and at th e fi el d worker level for short-term work. Exam ples of project-lev el long-term selections are th e absence of adulticiding by
th e C a pe C od project and th e strong push i n t o wet l a nds rest orat i on by th e Essex C ount y M C P. Short

- t e rm , project l e vel deci si ons revol ve around th e choi ce of l a rvi c i d es m a de avai l abl e t o fi el d workers, aeri a l work, and th e distribution of personnel am ong, surv eillance, source reduction and pestic ide application work. Project Superi nt endent s use th ei r experi ence, th e i nput of th ei r st aff, professi onal journal s , and any other resource th at can g u i d e th em in creatin g a q u a lity p r o g r am . An under-em phasized aspect of the selection process is the cost of each strategy. Strategies that cost

m o re than is available will not be im plem ented. Ground appli cation of larvicide is possible in larger areas than it is
current l y bei ng done, however th e m a npower requi rem e nt s are hi gh. Al t o si d appl i cat i ons for Cq . pert urbans popul at i ons control seem t o be l i m i t e d pri m ari l y due t o cost
. Fi el d st aff are responsi b l e for det e rm i n i ng th e need t o tr eat a gi ven si t e , th e t y pe of m a t e ri al t o use (forexam pl e, bri quet s versus a l i qui d tr eat m e nt i n a seri es of vernal pool s), and whether or not phy si cal control (rem ovi ng debri s cl oggi ng a cul v ert ) shoul d be done i m m e di at el y or can wai t for non-breedi ng peri ods. The effectiv en ess o f an y p r o g r am is d i rectly lin k e d to th e sk ill o f th e field staff in d e term in in g th e m o st ap p r o p r iate response to current local conditions and their m o tivati on to carry out the appropriate response effectively. On e o f th e g o a ls o f th e GEIR is to h e lp estab lish procedures for det e rm i n i ng whi c h control t echni que t o use. However, a l a rge am ount of basi c research i n t o m o squi t o and wet l a nds ecol ogy needs t o be done t o i m prove our basi c underst a ndi ng of th e cause and effect rel a t i ons hi ps am ong th e envi ronm ent and th e control procedures available. d. Evaluation of Efficacy No p r o j ect h a s d e v e lo p e d a co m p reh e n s iv e an d co m p arab le d a ta b a se o n m o sq u ito d e n s ities to d o c u m en t the long term im pact of control effort s on annoyance levels in their com munities. W h ile they m i ght be faulted for this failure, such an effort requires re sources th at m a ny project s do not have. Nearl y al l project s rout i n el y operat e l i ght tr aps or m a ke l a ndi ng rat e count s i n order t o m oni t o r adul t popul at i on l e vel s . Just how th ese dat aare anal y zed and used is not clear. No publicity or publications utilizing quantitative data on m o squito populations have been produced by any project. All projects seem to keep good records of how m a ny com p laints they receive annually from each section of their jurisdiction. Statistical treatm e nt of these data woul d be difficult and appears to have not b een attem p ted

. Larval sam p l i ng i s rout i n el y carri ed out by al l proj ects before pesticide applica tions. Post-treatm e nt checks are less com m on. However, one of the reasons the project s did not accept Altosid very qui ckly was that it was hard
to tell if th e treatm e n t h a d wo rk ed (th e larv ae can tak e u p to a week to d i e). Fro m th is it can b e in ferred th at p o s ttr eat m e nt m oni t o ri ng was occurri ng. Thi s is an area where a state-level entom o l ogi st woul d be of consi d erabl e hel p as she could carefully m onitor larvic ide applications with an eye towards developing m o re accurate delivery
t echni ques and appl i cat i on ra tes fo r v a ryin g situ atio n s . Post-treatm e nt m onitoring of adu lticide applications is done on an ad hoc basi s (Tabl e 10). A drop off i n

com p laint calls is the prim ar y criteria by which adulticiding efficacy is judged. W h ile aerial ULV applications are effect i v e (M ount et al . 1996), truck-m ounted ULV treatm e nts depend heavily on proper weather conditions and on th ere b e in g an ad eq u a te ro ad n e two r k

. Th e g e n e ral attitu d e , with th e n o t ab le ex cep tio n o f Cap e Co d , is th at th e resid e n t s p a y fo r m o sq u ito co n tro l an d ad u tlcid in g k ills m o sq u ito es. Dev e lo p i n g b e tter ev alu a tio n tech n i q u e s fo refficacy of truck-m ounted adulticiding would be a m a jor step in im proving m o squito control in Massachusetts.

e. Pu b lic Particip atio n Al l project s not i f y resi dent s by press rel ease or publ i c not i ce of th ei r i n t e nded control operat i ons for th e

com i ng season. M o st t o wns al so not i f y th e Depart m e nt s of Health and the chie f executive’s office of the

municipalities for which they do work of their plans for the season. In Norfo lk, each health board receives a notice of whi c h day s of th e week th e project m a y be tr eat i ng i n th ei r t o wn. M a ps are i n cl uded. Suffol k t a kes th e process one step further and notifies the m a yor’s office before each adulticide. W ith m i nor variations all proj ects do the

sam e t y pe of not i f i cat i on. R e quest s for excl usi on are handl ed vi rtual l y i d ent i cal l y by al l project s, wi th a l i s t of excl usi on si t e s gi ven t o dri v ers so t h at th ey know where t o not tr eat . M a ps of excl uded propert i e s are m a de avai l abl e t o th e spray crews. Mu ltip le Ch em ical Sen s itiv ity (MCS) is b eco m i n g an in creasin g l y im p o r tan t co n cern to h ealth o fficials as the num ber of individuals repor ting disabilities linked to chem ical exposure has increased dram atically over the past decade. Regardless, MCS has yet to beco m e a m a jor issue for m o squito control. In m o st cases, an individual with MCS can be accom m odated by the standa rd exclusion request since m o st m o squito control program s do not, as a general rul e , ask why an excl usi on i s request ed. Thi s l ack of confl i c t , however, shoul d not be t a ken t o m ean th at M C S i s a non-i ssue. M o squi t o control program s are desi gned t o prot ect peopl e, not harm th em , and i ndi vi dual s sufferi ng from M C S deserve t o have th ei r needs addressed. At th e sam e tim e, co n tro l p r o g r am s mu st tak e in to account th e needs of those who do not suffer from M C S, y e t do suffer from m o squi t o probl em s. So l ong as program s cont i nue t o work honest l y and above-board wi th M C S suffers (and any other group whi c h request s exclusion), and receives the sam e level of cooperati on from those requesting excl usion, mu tually acceptable sol u t i ons shoul d cont i nue t o be th e norm .One source for addi t i onal i n form at i on on M C S i s : M C S Referral & Resources, Inc. 508 W e st gat e R o ad Baltim ore MD 21229-2343 Tel e phone 410-362-6400 fax 410-362-6401 Publ i c educat i on i s a vi t a l com ponent of a com p l e t e program but current educat i on effort s represent onl y a t i n y part of m o st project s (Tabl e 5). Program s vary from di stri but i on of handout s upon request t o ful l

- scal e educat i onal present a t i ons, i n cl udi ng vi deos and other vi sual ai ds (Tabl e 11). In general , but not absol u t e l y , th e ext e nt of th e educat i on program i s a funct i on of program si ze. It is not clear that all projects use the Fact Sheets

cu rren tly av ailab l e fro m DPH. Th ese in clu d e “Eastern Eq u i n e En cep h a litis”, “In s ect b ites an d In sect rep e llen t s”, and “M osqui t o R e pel l e nt s” as wel l as a pam phl et “B ugged by M o squi t o es? ” E. Eastern Eq u i n e En cep h a litis 1. Responsibility for Surveillance and Control. Eastern Equine Encephalitis (EEE) is an alphavirus endem i c to m a ny passerine bird species found in freshwater swam p habitats. The virus is transm itte d am ong wild bird populations in these areas by C s . mel anura , a

m o squito species that feeds alm o st ex clusively on birds. The freshwater sw am p is the enzootic focus of EEE and under norm a l conditions the virus is restri cted to this habitat, Occasionally, however, due to factors which include seasonal and yearly rainfall levels and tem p eratures, m o squito virus m a y “spill over” into m a m m a lian populations. Thi s phenom enon i s due t o th e tr ansm i ssi on of th e vi rus from i n fect ed bi rds t o m a m m a l s by one of m o re m o squi t o species which feed on both hum ans and birds. Species th at transm it disease from norm a l reservoirs to accidental hosts are known as “bridge vectors”. The Massachusetts m o squito species traditionally thought to be likely bridge vector species are Cq. perturbans, Ae. vexans, Ae. sollicitans, and Ae. canadensi s . Recently published studies also suggest th at Anophel e s species and Cx. sa lin a r iu s m a y be possi bl e epi d em i c vect ors (Edm an et al . 1993; Vaidyananthan et al. 1997). EEE viru s has been isolated from all of th ese species. The bridge vector(s) responsible for EEE transm ission to hum ans has not, however, been unequivocally identified. EEE is a rare form of encephalitis with a high rate of m o rtality. The overall case fatality rate is now about 3 0 % an d su rv iv o r s o f ten su ffer lifetim e d i sab ilities. Th e sev e rity o f illn ess ten d s to b e m o st g r av e at th e ex trem es o f age. Fatality rates are highest am ong th e elderly and interm ediate in children. Infants and children who survive theTabl e 11. Publ i c Educat i on Program s. Pro j ect Visit Co m p lain t Giv e Talk s No tes o n Pro g r am s/Pam p h l ets Av ailab l e C a l l e r s B e rkshi r e Yes Yes UM ss C oop Ext e nsi on Leafl e t “M osqui t o es” th e “Ten C o m m a ndm ent s of M o squi t o C ontrol ” B ookm ark for school s B r i s t o l C ount y Yes No Suppl y i n form at i on upon request C a pe C od Yes Yes C onduct s school program s for al l age groups, have devel oped and di stri but e an i n form at i onal pam phl et , and rout i n el y appear i n l o cal press. Cen tral Mass Yes Yes News releases to m e m b er mu n i cip a lities’ p r ess Project st aff at t e nd vari ous m eet i ngs A vi deo “W orki ng for You”, a di spl a y and a slide show are all available Pam phl et s are di stri but ed t o B o ards of Heal th and other offi ces and any one el se who requests them

. School program for el em ent a ry school s. East M i ddl esex Yes Yes School eduat i on program (three grade groups: 1-3, 4-6, and 7+) Gi ve t a l k s upon request
. 20-m i nut e vi deo DPH fact sheets Pam phl et on M o squi t o IPM Essex Not m e nt i oned Not m e nt i oned Fact sheet s avai l abl e on request 3-panel di spl a y avai l abl e t o envi ronm ent a l groups Outreach through environem e ntal groups Norfol k Som e t i m es Yes Fact sheet s: IPM , B t i , M e thoprene, The Fact s about M o squi t o Spray i ng Materials su p p lied to lo cal Bo ard s o f h ealth Provi des i n t e rvi e ws on Local C abl e TV Personnel al way s avai l abl e for t o wn-sponsored m eet i ngs Has ext e nsi v e school program Atten d lo cal h ealth fairs Pl y m outh Som e t i m es Yes Speaker program : spokesperson avai l abl e y ear-round for any com muni t y group Utilizes co m mu n ity ch an n e l o n cab le TV Pesticid e in fo rm atio n d i strib u t ed to to wn s an d avai l abl e t o resi dent s upon request DPH fact sheets and pam phlet “Hom eowner M o squi t o C ontrol ” pam phl et Suffol k Yes Yes (School s) Press rel eases i n th e spri ng Fax e s to m a yo r p r io r to treatm e n t i n fect i on are m o st l i k el y t o be perm anent l y neurol ogi cal l y i m pai r ed and oft e n requi re l i f el ong support i v e care.Horse cases of EEE have been described as early as the nineteenth century in Massachusetts and hum an cases were likely to have occurred, although they were not recognized as EEE prior to 1938. Since the first recognized outbreak of hum an EEE in 1938, 74 cases have o ccurred in Massachusetts with cases disproportionately concentrated in the south-central and southeastern parts of the state. Four mu lti-year outbreaks of hum an EEE have been reco rded in the central-eastern and southeastern areas of Massachusetts,. Thirty-four (46%) cases were identif ied in 1938. Subsequent years of hum an EEE cases have been 1939 (1 case), 1955 (4 cases), 1956 (12 cases), 1970 (1 case), 1973 (2 cases), 1974 (3 cases), 1975 (1 case), 1982 (2 cases), 1983 (6 cases), 1984 (2 cases), 1990 (3 cases), 1992 (1 case), 1995 (1 case) and 1997 (1 case). The two worst years for hum an cases of EEE (1938 and 1956) occurred before there was an EEE Surveillance Program . However, it is assum e d that the virus carriage of m o squitoes, and m o squito populations, woul d have been unusual l y hi gh com p ared t o average l e vel s of th ese i ndi cat ors. Si nce th e begi nni ng of a prospective EEE Surveillance Progr am , there have been two years of extraord inarily high levels of virus carriage in

m o squitoes, in 1973 and 1990. Although only a sm all num ber of hum an EEE cases were identified in 1973 (2 cases) and 1990 (3 cases), there were significan t control interventions in each of the two outbreak years. W i de-area spray i ng wi th ULV m a l a th i on was done t o reduce popul at i ons of th e vect or speci es. In 1990, in response to surveillance data showi ng alarm i ngly high and increas ing EEE virus levels in

m o sq u ito es, mu ltip le h o r se cases, an d th e risk o f mu ltip le h u m an cases, th e larg est aerial ap p licatio n (ULV) o f

m a lath io n in years was m a d e o v e r mu ch o f so u th eastern Massach u s etts. Th ree p e o p l e co n tracted th e illn ess p r io r to th e tr eat m e nt and one di ed. As a resul t of t h i s out break, t h e Depart m e nt of Publ i c Heal th and t h e St at e R ecl am at i on B o ard sought t o strengthen t i e s bet w een st at e and project offi ci al s and t o bet t e r defi ne th ei r response t o futu re out breaks. W h i l e th ere was consi d erabl e controversy over what som e fel t t o be an extr em e response by th e st at e, th ere can be no quest i on th at m o squi t o popul at i ons were effect i v el y redu ced by th e appl i cat i on and th at no new hum an cases of EEE occurred after the treatm e nt. Mount et al. (1996) provide an excellent review of aerial applications of insecticide for m o squito control and c onclude that ULV applications are e fficacious, cost effective and can work over dense fol i a ge or open housi ng. The resul t s i n 1990 i n M a ssachuset t s support th ese concl u si ons. 2. Effect of EEE on Projects Of the nine Projects, Berkshire is outside the EEE ri sk area and Cape Cod and E ssex County are defined aslow-risk areas. The other Projects provide significant support for EEE m onito ring and m o squito control. W h en request ed l a rval and adul t m oni t o ri ng dat aare al so suppl i e d by th e Project s t o DPH. B r i s t o l , Norfol k , Pl y m outh and East M i ddl esex M C Ps tr adi t i onal l y i n crease tr uck-m ount ed aerosol appl i cat i ons i n areas of hi gh publ i c use when DPH indicates elevated risk of EEE. These Projects also supply support for, or actually conduct, aerial applications for l a rval (B t i ) or adul t (m al athi on) m o squi t o control at th e request of DPH. Though the Projects do not target EEE vectors specifically, unless so di rected by DPH, their general operations perm it surveillance and contro l work to be carried out against v ector species as necessary. As an

exam pl e, East M i ddl esex has 50 C D C l i ght tr aps set up th rough out i t s di stri ct , a port i on of whi c h m oni t o r Cs. mel anura popul at i ons. East M i ddl esex has al so conduct e d aeri a l appl i cat i ons of Al t o si d pel l e t s t o control Cs. mel anura . Em phasi zi ng th e probl em of Cq . pert urbans , however, East M i ddl esex has been unabl e t o devel op a larv a co n tro l p r o g r am to ad eq u a tely d eal with th is p o t en tial v ecto r . A cont i nui ng source of fri ct i on i s th e defi ni t i on of a nui sance versus a health threat. W h ile several projects were form ed as mu ch because of the possibility of EEE as the nuisance factor , no project today considers preventing EEE to be their prim ary goal. Fortunately, DPH and the Pr ojects in EEE areas work well together and a system of graduated responses (from regi onal ground control up to state-m a ndated aeria l adulticiding) has been put in place.IV. DESCRIPTION OF M O SQUITO SPECIES AND ABATEM ENT HABITATS A. Mosquito Species 1. General B i ol ogy M o squi t o es bel ong t o th e fam i l y C u l i c i d ae of th e Order Di pt era (true fl i e s), i n sect s wi th one pai rof cl ear wi ngs. There are 167 North Am eri can speci es i n 13 di fferent genera (Darsi e and W a rd 1981). Of th ese, 46 i n 9 di fferent genera have been found i n M a ssachuset t s (Tabl e 12). About one-h al f of th ese (from 5 di fferent genera)

m a y at tim es cause significant hum an annoyance in cer tain localities; the m a jority belong to the genus Aedes . No

m o squi t o speci es feeds excl usi v el y on hum ans. Those speci es th at annoy hum ans feed on a wi de vari et y of other

m a m m a ls and occasionally on birds as well. Som e non-hum an-biting species such as Cs

. mel anura , Cs

. morsi t ans and Cx

. rest uans can be i m port a nt i n th e m a i n t e nance of enzoot i c di sease cycles in wildlife. Som e of these diseases, e.g., Eastern equine encephalomy elitis (EEE), occasionally spill over into hum an populations via transient epidem ic vectors. M o squi t o l i f e cy cl es can be grouped i n t o t w o basi c t y pes: perm anent

- wat e r and t e m porary - wat e r (or fl ood-wat e r). Tem porary - wat e r speci es general l y bel ong t o th e genus Aedes or Psorophora and present th e m a jor pest probl em i n Massachusetts. Adult fem a les can readily be distingui shed from perm anent water form s because their abdom en t e rm i n at es i n a sharp poi nt form ed by th e ext e nded cerci . Thi s group overwi n t e rs as dorm a nt eggs l a i d si ngl y by fem a l e s (usual l y ca. 75-150/ fem a l e ) i n th e band of m o i s t soi l surroundi ng th e evaporat i ng t e m porary pool s i n whi c h
th e l a rval st ages devel oped. Hat c h (st i mul ated by increased tem p erature or reduced O 2 ) occurs when these depressi ons are fl ooded by t i d es, rai n s, i rri gat i on or fl oodi ng ri vers. The eggs of m o st t e m p erat e fl ood-wat e r species mu st undergo a prolonged cold -conditioning period prior to hatch so there is norm a lly only a single generation early each season (univoltine species). In a few species such as the eas tern saltm arsh m o squito, Ae

.
so llicita n s , eggs laid in the earlier part of the season will hatch after only 2-4 weeks of conditioning so mu ltiple generations (multivoltine) are com m onplace. The term s generation and brood are not always synonym ous because not all eggs hatch when floodi ng occurs, so that mu ltiple broods m a y som e tim es occur from a single generat i o n of overwi n t e ri ng eggs. In M a ssachuset t s , refl ood speci es l i k e Ae

. vexans , Ae

. sticticu s , and Ae

. trivitta tu s (and perhaps late sp rin g - h a tch sp ecies lik e Ae

. canadensi s and Ae

. ci nereus ) m a y h a v e mu ltip le g e n e ratio n s o rj u st mu ltip le broods caused by del a y e d egg hat c h. In spri ng, l a rval de vel opm ent of t e m porary - wat e r m o squi t o es m a y requi re t w om onths or m o re
Tabl e 12. Sy st em at i c Index of th e C u l i c i d ae of M a ssachuset t s Taxon Taxon Genus AEDES Genus CULEX Subgenus Aedes Subgenus Culex ci nereus (M ei gen) pi pi ens Linnaeus rest uans Theobal d Subgenus Aedemorphus sa lin a r iu s Co q u illett vexans (M ei gen) Subgenus N e ocul ex Subgenus Ochl erot at us t e rri t ans Wa l k e r abserratus (Fel t & Young) at ropal pus (Co q u illett) Gen u s CULISETA auri f

e r

(Co q u illett) canadensi s (Theobal d ) Subgenus C l i m acura cant at or (Co q u illett) mel anura (Co q u illett) communi s (De Gerr) d ecticu s Howard, Dy ar & Knab Subgenus Cu licella di ant aeus Howard, Dy ar & Knab morsi t ans (Theobal d ) dorsalis (M ei gen) mi nnesot a e Barr ercruci ans (W alker) fitch ii (fel t & Young) Subgenus Cu liseta imp lica t u s Vockeroth imp a tien s (W alker) i n t r udens (Dy a r) i nornat a (W illisto n ) provocans (W alker) punct o r (Ki rby ) Genus ORTHOPODOMYIA so llicita n s (W alker) signifera sticticu s (M ei gen) st i m ul ans (W alker) Genus PSOROPHORA taeniorhynchus (W i e dem a nn) trivitta tu s (Co q u illett) Subgenus Grabhami a co lu mb ia e (Dy a r & Knab) Subgenus Prot om acl eay a hendersoni C o ckeral l Subgenus Jant hi nosoma triserla tu s (Say ) fero x (von Hum bol dt ) Genus ANOPHELES Subgenus Psorophora cilia ta (Fabricius) Subgenus Anophel e s barberi Co q u illett Gen u s URANOTAENIA cruci ans W e i d em ann Subgenus Uranot aeni a earlei Vargas sapphi ri na (Osten Sacken) punct i p enni s (Say ) quadri m acul at us (Say ) Genus WYEOMYIA walkeri Theobal d Subgenus Wyeomyia Genus COQUILLETTIDIA smithii (Co q u illett) Subgenus Co q u illettid ea pert urbanswh ile in su m m e r it m a y b e as b r ief as 4

- 6 d a ys. Perm an en t-water m o sq u ito es d e p o s it th eir eg g s (g en erally a

mu lti-egg raft of ca. 100-250 eggs except in the Anophel e s ) on the surface of perm anent or sem i -perm a nent (i.e. persi s t s for several weeks) wat e r and hat c h occurs wi th i n 1-3 day s . Popul at i ons are asy n chronous com p ared t o fl ood-wat e r speci es (wi th several overl appi ng generat i ons), and l a rval devel opm ent t e nds t o be l onger. Som e perm anent water species (e.g., Cq . pert urbans , Cs

. mel anura and Cs

. morsi t ans ) overwi n t e r i n a di apausi ng l a rval stage, but m o st overwinter as hiberna ting adult fem a les that are fertilized, nu lliparous (never having produced eggs), and non-bl ood-fed. M o squi t o es m e t a m o rphose i n t o th e wi nged adul t st age wi th i n th e nonfeedi ng pupal st age. The pupa i s active and aquatic (called tum b lers) and is resistant to m o st chem ical control m easures (suffocating surface film s are an except i on). It norm a l l y l a st s onl y 2-4 day s . M a l e s gene ral l y pupat e and em erge about 1 day ahead of fem a l e s of
th e sam e cohort

. M a t i ng m o st com m onl y occurs i n t w i l i ght swarm s wi th i n 2-3 day s aft e r fem a l e s em erge. M o st , but not al l , fem a l e s m a t e before th ey t a ke bl ood. B o th sexes feed frequent l y on pl ant nect ar; fem a l e s t a ke bl ood i n order t o obt ai n prot ei n for egg devel opm ent
. A few speci es are aut ogenous, m eani ng th ey do not need a bl ood m eal t o produce eggs. One Massachusetts speci es, th e p itch e r p l an t m o sq u ito ( Wy. smith ii ), never t a kes bl ood. M o st fem a l e s begi n seeki ng host s 2-4 day s aft e r em ergence but som e speci es (e.g., Cs

. morsi t ans ) m a y delay feeding for 2 weeks or m o re. Thus, th e t i m e peri od bet w een adul t em ergence and th e fi rst egg l a y i ng (fi rst gonotrophi c cy cl e) i s usual l y 7-10 day s . Subsequent host -feedi ng t o egg-l a ying cycles in m o st tem p erat e speci es requi re 4-6 day s . Species that transm it disease (vectors) mu st feed at least twice, once to acqui re th e i n fect i on, and once t o tran sm it it, u n l ess th e in fectio n is acq u i red tran so v a rially (in t o th e eg g wh ile in th e o v a ry) fro m th eir m o th er. Th is

m eans th at fem a l e s mu st norm a l l y survi v e for 12-14 day s i n order t o be a vect or. If th e extr i n si c i n cubat i on peri od of th e pathogen/ parasi t e i n th e m o squi t o i s l onger th an th e gonotrophi c cy cl e, as i s oft e n th e case, th e survi v al t i m e requi red for tr ansm i ssi on i s even l onger. Most fem a les do not survive beyond the first oviposition but a few individuals in a ll m o squito populations l i v e a l ong t i m e (i .e., several weeks). Except i onal l y , overwi n t e ri ng adul t s l i v e 5-7 m onths. M a l e s general l y survi v e for short e r peri ods th an fem a l e s and never overwi n t e r.2

. Saltm arsh m o sq u ito es Th e lead in g p e st m o sq u ito p r o b l em in co astal co m mu n ities in Massach u s etts is cau sed b y two b r ack ish water species, Ae

. so llicita n s and Ae

. cant at or . The l a t t e r speci es i s abundant onl y i n th e earl y part of th e season (m id-M ay to m i d-June); Ae

. so llicita n s is th e m a j o r targ et o f m o st saltm arsh m o sq u ito co n tro l effo rts. Bo th sp ecies devel op i n pans i n th e hi gh sal t m a rsh (dom i n at ed by Spart i n a grasses) whi c h are norm a l l y onl y fl ooded by m oon tides. Heavy rains or high tides caused by unusual winds can also cause interm ittent flooding in the high m a rsh. Ae. cant at or t e nds t o occur m o re i n th e extr em e upl and edge of th e hi gh m a rsh. Thi s area i s oft e n qui t e fresh and

m a y in clu d e p l an ts su ch as cattails. Un m a in tain ed m o s qui t o di t c hi ng can becom e an i m port a nt breedi ng area, as Spartina alterniflora prevent s th e di t c hes from drai ni ng and shal l o w wat e r i s hel d bet w een m oon t i d es. Aedes taeniorhynchus is a th ird sp ecies th at o ccu rs in salt m a rsh e s, o f ten in co n j u n c tio n with Ae.

so llicita n s . C o m p l i cat i ng th e control pi cture further i s Cx. sa lin a r iu s wh ich so m e tim es b r eed s in after h eav y, latesu m m e r rain s. As a resu lt, salt m a rsh e s g e n e rally req u i re m o n ito rin g at least twice a m o n th (o n ce after th e fu llm oon hi gh t i d e and once aft e r th e new-m oon hi gh t i d e) as wel l as aft e r any m a jor rai n event
. W i th regard t o sal t m arsh m o squi t o control , one shoul d al way s assum e th at th ere are huge num bers of eggs avai l abl e t o hat c h aft e r any flooding; any other assum p tion will result in broods be ing m i ssed and adult m o squitoes swarm i ng in num bers
not easi l y underst ood by one who has not experi enced th em . Uncontrol l e d popul at i ons of sal t m a rsh Aedes often reach extrem ely high biting densities (i.e., 100+ fem a les landing/m i nute). Adults m a y not be particularly long lived, but becau se m oon tides occur so regularly and

o f

ten , mu ltiv o ltin e Ae

. so llicita n s can be a problem throughout the sum m e r season. Because the econom ies of

co astal areas affected b y th is m o sq u ito o f ten d e p e n d h eav ily o n su m m e r to u r ism , th e im p act o f saltm arsh

m o sq u ito es is g r eatly m a g n i fied . Th is is reflected inthe percent effort coasta l project s spend on sal t m arsh Aedes
control (Tabl e 9). Sal t m a rshes and th e estu ari e s th ey feed are th e pri n ci pal nursery grounds for a vari et y of m a ri ne and b r ack ish water o r g a n i sm s, in clu d i n g sev e ral co m m e rcial fo rm s. Disru p tin g th ese v ital wetlan d s to co n tro l saltm arsh

m o squi t o es can cause uni nt ended, l ong-t e rm probl em s. 3. Freshwat er m o squi t o es. The m o st severe and predi c t abl e l a t e -spri ng t o earl y -sum m e r m o squi t o annoy ance i n al l i n l a nd (and m a ny coast a l ) areas i s caused by several speci es of Aedes collectively referred to as spri ng-hat c h or snow-pool m o squi t o es, th e m o st com m on of whi c h i s Ae. canadensi s . Th ese m o sq u ito es ten d todevel op i n si m i l a r aquat i c si tu at i ons (i .e., t e m porari l y fl ooded woodl and depressi ons i n cl udi ng th e fl ooded borders of perm anent swam ps and bogs) and have si m i l a r l i f e cy cl es . They overwi n t e r as dorm a nt eggs and have a si ngl e, spring generation each year (univoltine). Adult m o squitoes are m o st active from late spring to m i d sum m e r; the fem a les taking blood m eals and depositi ng their eggs in the m o ist soil a nd leaf litter around the edges of the evaporat i ng woodl and pool s i n whi c h th ey devel oped as l a rv ae. They are part of a l a rger groupi ng of m o squi t o es cal l e d t e m porary - wat e r or fl ood-wat e r speci es whi c h al l ha ve eggs th at hat c h sy nchronousl y when fl ooded by rai n , tide, snow m e lt or rising rivers. In this case, snow m e lt and spring rain fill the woodland depressions that are
st ocked wi th eggs, usual l y causi ng hat c h som e t i m e i n earl y M a rch. M i l d condi t i ons i n l a t e February and earl y March followed by severe cold, or sp ring precipitation, can reduce larval popul ations by freezing or flooding. As a resul t , consi d erabl e y ear-t o-y ear popul at i on vari at i on occurs. Spri ng-hat c h Aedes can be subdi vi ded i n t o t w o m a jor groups, dark-l egged and banded-l e gged, based part l y on th e phy si cal appearance of bi t i ng fem a l e s and part l y on som e m i nor differences in their life cycles. The dark-l egged group hat c h and em erge about 1-3 weeks aheadof th e banded-l e gged group and seem t o survi v e as adul t s for a short e r peri od of t i m e. Som e m e m b ers of th i s group (e.g., Ae

. punct o r ) becom e m o re abundant at

m o re north ern l a t i tudes (coni ferous forest zone) and at hi gher el evat i ons (e.g., near t h e t op of th e Hol y oke R a nge). W h en people enter the densely shaded daytim e resting places of these m o squitoes, fem a les attack m o re aggressively
th an do m e m b ers of th e banded-l e gged group such as Ae. st i m ul ans and Ae. canadensi s . Dark-l egged Aedes appear to be the principal vectors of Califor nia group encephalitis viruses. These vi ruses overwinter inside the eggs of
th ei r m o squi t o vect or (C al i s her & Thom pson 1983). The banded-l e gged group oft e n devel op i n th e sam e pool s and rest i n th e sam e wooded, day t i m e rest i ng habi t a t s as som e speci es i n th e dark-l egged group. Howeve r, th ey t e nd t o di sperse further from th e l a rval habi t a t and, duri ng th e earl y eveni ng bi t i ng peak of both groups , banded-l e gged fem a l e s feed m o re readi l y i n open and

sem i -wooded habi t a t s th an t o dark-l egged fem a l e s. So m e banded-l e gged fem a l e s survi v e i n t o August , and th i s group seem s t o be th e pri n ci pal vect or of dog heart w orm i n W e st ern M a ssachuset t s . Al though th e general l a rval habi t a t of both groups i s si m i l a r, consi d erabl e vari at i on i n habi t a t occurs and

som e species are m o re restricted than ot hers. For exam pl e, cert a i n dark-l egged Aedes are m a i n l y found i n association with cranberry ( Ae

. auri f

e r ) or sphagnum (

Ae

. d ecticu s ) bogs. Spri ng woodl and pool s vary from sm al l , shal l o w depressi ons form ed by fal l e n tr ees t o l a rge, deep ravi nes i n m ount ai n bedrock and natu ral swal es i n forest edfl ood pl ai ns. Perm anent woodl and or grassy swam ps and bogs are al so a com m on source of som e m e m b ers of th e spri ng Aedes group.

a . Aedes canadensi s . Aedes canadensi s i s perhaps th e dom i n ant spri ng-breedi ng m o squi t o i n th e Northeast

. It ’s pri m ary habi t a t i s woodl and ve rnal pool s; pool s th at havi ng st andi ng wat e r from snow-m el t

u n til early su m m e r. Larv ae can b e co llected ev en b e fo re th e last fro sts b u t d e v e lo p m en t is slo w d u r in g th e co o l spring m onths and adults usually do not em erge until near the end of May or in early June. Although Ae. canadensi s i s an act i v e bi t e r, i t does not general l y fl y far from th e woods i n whi c h i t breeds. As resi dent i a l areas have cut th ei r way i n t o th e woods of M a ssachuset t s , however, Ae. canadensi s has becom e an increasing problem

. Aedes canadensi s control is difficult because the pools in whic h it breeds are isolated from each other. A

sm al l woodl ot can cont ai n m a ny pool s, som e of whi c h m a y requi re fi el d workers t o cut th rough poi son i v y ,
mu ltiflora rose, and bull brier just to reach. Ground appli cation of larvicide under such circum stances is tedious

an d , reg a rd less o f in ten t , o f ten less th an co m p lete. Aedes canadensi s is predom inantly univoltine, but a second brood (either delayed hatch of over-wintering eggs or early hatch of spring-laid eggs ) can develop in early fall if rainfall is sufficient to partially fill the woodland pool s. In such cases, tr eat m e nt i s nearl y i m possi bl e, as a sum m e r’s growth of th e above-m ent i oned pl ant s , coupl ed with a dense canopy of leaves from the m a ny shrubs th at line the pools m a ke getting to the pool, and placing the
correct am ount of pest i c i d e i n th e pool , extr em el y di ffi cul t
. b

. Aedes vexans . Aedes vexans i s th e m o st ubi qui t ous fl oodwat er m o squi t o i n North Am eri ca and i s th e predom i n ant sum m e r refl ood m o squi t o i n M a ssachuset t s . Aedes vexans i s found i n l a ke and ri ver fl ood pl ai ns, shrub swam ps, fl ooded m eadows, and sha l l o w grassy depressi ons associ at ed wi th open habi t a t s such as roadside ditches, pastures, gol f courses and athletic fields. It will also breed in woodland pools and shallow
cat t a i l m a rshes, such as those th at devel op i n som e ret e nt i on ponds. The fi rst Ae. vexans are norm a l l y not on th e wi ng before m i d-June. Popul at i ons of Ae. vexans are unpredictable because they depend entirely on the frequency and spaci ng of m a jor rai n s. R a i n fal l of 1 i n ch m a ny produce som e Ae. vexans but i t

usual l y requi res 3” of rai n wi th i n a short peri od of t i m e (several day s ) t o produce a l a rge brood. Larval broods of Ae. vexans have been observed as l a t e as m i d-Sept em ber i n Amherst

. It i s not al way s cl ear whet her such l a t e season broods resul t from th e del a y e d and st aggered hat c hi ng of eggs t h at are a y ear or m o re ol d or from th e hat c hi ng of non-di apausi ng eggs l a i d ear l i e r th e sam e season. B r ust and C o st el l o (1967) andHorsfall et al (1973) have shown th at m a ny speci es such as Ae. vexans lay som e eggs that will hatch without cold condi t i oni ng. Sequent i a l hat c hi ng of eggs i s al so wel l docum ent e d i n fi ve refl ood Aedes species (i.e., canadensi s , cin e reu s , sticticu s , trivitta tu s, and vexans ). Larval devel opm ent i s rapi d, 4-6 day s , and th e pupal st age l a st s for about 2 day s . Hence, th e wi ndow for effect i v e l a rval / pupal control i s narrow. M o reover, a l a rge num ber of
scat t e red pool s al l need t o be tr eat ed wi th i n th e sam e bri e f t i m e span fol l o wi ng m a jor rai n s. C ontrol effort s suffer fro m th e sam e d i fficu lties as d e scrib e d fo r Ae. canadensi s , as Ae. vexans will o f ten b r eed in m i d

- su m m e r in th e

sam e pool s used by Ae. canadensi s in th e sp rin g .
c. Addi t i onal Aedes species Lesser, but at

t i m es si gni fi cant , popul at i ons of Ae. triseria tu s , Ae

. trivitta tu s and Ae

. sticticu s do occur i n M a ssachuset t s . Larvae of th e l a t t e r t w o speci es are associ at ed wi th ground pool s i n wooded or sem i -wooded fl ood pl ai ns. Extrem ely heavy general rains sufficient to cause river flooding co m m only proceed large populations of Ae. trivitta tu s and Ae. sticticu s . Aed e s triseria tu s is a treeh o l e m o sq u ito , b r eed in g in th e wild in holes left in trees when a branch breaks off

an d/ o rin sect d a m a g e cau ses a p a rt o f th e tree to ro t o u t . W ith in th e sh ad ed fo rest it is a read y b iter b u t it d o e s n o t venture far from it’s breeding areas. Because it’s larval hab itat is widely dispersed (and often well above the height that a person could reasonably be expect ed to reach), larval control is not possible. Fortunately, because it stays wi th i n th e woods, control t a rget i ng Ae. triseria tu s is rarely necessary . Aed e s triseria tu s o v e rwin ter as eg g s in th e larv al h ab itat; h at c hi ng occurs i n earl y spri ng and devel opm ent to the adult stage takes about 3 m onths. The first biting adults appear in late June in Massachusetts. Larval populations are often crowded and asynchronous so som e em ergence continues until early August. A second generat i on of l a rvae has been observed, especi al l y i n t i r es, where wat e r i s usual l y warm er and devel opm ent i s fast er. However, it is doubtful that m a ny adults from this genera tion are successful at this latitude. This m a m m a l-feeding, d i u r n a l sp ecies d o e s n o t n o r m a lly d i sp erse far fro m its sylv an larv al h ab itats. Bitin g ad u lts are p a rticu l arly activ e in the late afternoon, pre-twili ght period (i.e., 4-7 PM). If Ae. triseria tu s st ay ed i n th e tr ees, i t woul d be a m i nor pest , but i t

has becom e wel l adapt e d t o breedi ng i n tires, p a rticu l arly wh ere th ey are shaded. As a result, Ae. triseria tu s can be a locally im portant pest wherever rim l ess tires are stored. Tire rem oval, and the pr evention of illegal tire dum ping along wooded roads, is an i m port a nt part of m o squi t o control

.Aedes at ropal pus i s another natu ral cont ai ner breeder, but i t

i s associ at ed wi th rock pool s, especi al l y those i n exposed ri verbeds. The north ern form i s aut ogenous for th e fi rst egg bat c h so i t i s a l e ss bothersom e day t i m e pest speci es th an i t s southern si bl i ng, Ae

. epact i u s . This species has also becom e ad ap ted to tires in th e Mid w est. A new Asi a n cont ai ner breeder, Ae. al bopi ct us , has recently been introduced into the Southern United St at es (Texas), apparent l y vi a i m port e d used tr uck t i r es (M oore 1986). Thi s di urnal urban pest th roughout Asi ahas already spread as far north as Indiana and is likely to appear in Massachuse tts at som e point (Nawrocki & Hawley 1987) Locations where used truck tires are brought in a nd stored for recapping are the m o st likely points of i n tr oduct i on. Thi s speci es has m a i n l y been found i n t a res i n th e Uni t e d St at es t o dat e . It i s an effi ci ent l aborat ory vect or of m a ny W e st ern Hem i sphere arbovi ruses (Short e r 1986). d

. Culex species. Culex m o squitoes have an am biguous place in m o squito control in M a ssachuset t s . On th e one hand, th ey are com m onl y encount ered as l a rvae i n st orm drai ns, ci st erns, drai nage basi ns and other cont ai n-t y pe si tu at i ons but , on th e other hand, th e ext e nt t o whi c h th ey cause bi t i ng probl em s for people and are involved in the transmission of disease, for exam ple ence phalitis between birds, is unknown. Species such as Cx. territa n s and C x . rest uans are cert a i n l y not pest s of hum ans, but C x . rest uans m a y be i nvol ved in transm ission of EEE between birds (it is com m on to pick up EEE in Culex pool s i n areas where i t i s present i n C

s . mel anura pool s–th e probl em bei ng th at Culex pool s are rarel y sort ed t o speci es before t e st i ng). Culex m o sq u ito es are mu ltiv o ltin e, h a v i n g sev e ral g e n e ratio n s p e r year. Th ere can b e co n s id erab le o v e rlap

am ong th e generat i ons. Adul t fem a l e s overwi n t e r and are am ong som e of th e fi rst m o squi t o es t o be seen i n th e spri ng. Cu lex m o squi t o es do not bi t e duri ng th e day and are m o re act i v e l a t e r at ni ght th an are m o st Aedes species. The house m o squi t o , C x . pi pi ens , b r eed s p r o lifically fro m m i d to late su m m e r in u rb a n sto r m sewers,

ornam e nt al / w adi ng/ swi m m i ng pool s, bi rd bath s, pl ugged ra i n gut t e rs, t i r es, car bodi es, em pt y barrel s , and other sim ilar m a nm ade containers. This species tolerates polluti on, so the highest densities often occur in eutrophic water enriched by anim al waste (e.g., se wage oxidation ponds). Multiple, overl apping generations (each requiring 8-10 day s ) occur i n th e sam e habi t a t
. M a t e d but non-bl ood-fed fem a l e s produced l a t e i n th e season overwi n t e r i n underground sewers, basem e nts, and other protected places. The southern form , C x . pi pi ens qui nquef a sci a t u s , feeds readi l y on both m a m m a l s and bi rds (Edm an 1974), but th e north ern form , C x . pi pi ens pi pi ens , wh ich o ccu rs in Massach u s etts, is m a in ly asso ciated with av ian h o s ts. In l a rge urban cent e rs i n th e North, a l e ss com m on aut ogenous form ( C x . pi pi ens mol e st us ) ex ists. It read ily attack shum ans after the initial blood-free gonotrophic cycle is com p le ted. This form has been docum ented in Boston, where i t i s associ at ed wi th underground sewers and subway tunnel s (Spi el m a n 1973). C x . rest uans i s oft e n found i n

som e of th e sam e cont ai ner habi t a t s as C x . pi pi ens . Cu lex sa lin a r iu s di ffers from th e above-m ent i oned Culex sp ecies in th at it is an active hum an biter and can occur i n si gni fi cant num bers. It ’s breedi ng habi t s are poorl y underst ood as i t i s general l y cl assed as a perm anent

pool breeder but dense l a rval popul at i ons have been found i n rai n -fed pool s i n sal t m a rshes i n R hode Isl a nd (salinities close to 0 ppm ) and large adult populations existed in the coastal residential ar ea of Bonnet Shores, RI in 1986 (C hri s t i e , personal com muni cat i on). Th e ex ten t to wh ich Culex species require control can be debated. Species such as Cx. territa n s alm o st certain ly p l ay n o ro le wh atso ev er in eith er p e st o rd i sease p r o b l em s. Ho wev e r, th e ab ility to id en tify m o sq u ito l a rvae t o speci es i s oft e n not wel l devel oped and fi el d i d ent i f i cat i on can be di ffi cul t (though separat i ng A edes from Cu lex requires little m o re than direct obser vation). Under such circum stances, tr eatm e nt of any larval population is
th e general rul e . Defi ni ng th e rol e of Culex species in the m a gnification of EEE within the bird population would aid in d e term in in g th e ex ten t to wh ich larv al co n tro l o f Culex should take place.

e . Cu liseta species C u l i s et a mel anura o ccu p i es an in terestin g p o s itio n in Massach u s etts m o sq u ito co n tro l in th at it is th e o n l y known vector species in Massachusetts that is not also a significant pest. Therefore, controlling C s . mel anura in th e larval stage, especially prior to docum entation of EEE in adult C s . mel anura popul at i ons, i s controversi a l i n th at th e MCPs, as established, are not expected to target vector m o squitoes as a part of their routine work. The decision as
t o whether or not t o at t e m p t

l a rval control woul d be m a de easi e r i f C s . mel anura bred i n habi t a t s occupi ed by other pest species such as Ae. vexans or Ae. canadensi s . Unfortunately, C s . mel anura breeds in a very specific habitat,
th e hol es th at devel op around th e root s of tr ees wi th cedar/m apl e swam ps and i s not rout i n el y affect ed by tr eat m e nt work for other species. In fact, because the holes are not interconnected and are of ten have only sm all openings, they are extrem ely difficult to tr eat even when the decision has b een m a d e to attem p t larv al C s . mel anura control

. Other Cu liseta species exist in the state but have not been i d ent i f i e d as vect ors of di sease or pest s of hum ans. f

. Co q u illettid ea (form erly Mansoni a ) pert urbans . Am ong a group of i n sect s al ready di sl i k ed by hum ans, Cq . pert urbans st ands out as bei ng part i c ul arl y di sl i k ed by m o squi t o -control personnel

. Fi rst ,it is a large, aggressive biter that sp arks com p laint calls like few other m o s quitoes and, second, because the larva lives attached to the stem s of cattail, it is exceedingly di fficult to m onitor and control In M a ssachuset t s , Cq . pert urbans has one generat i on per y ear. It overwi n t e rs in the larval stage (3rd instar) and adul t s begi n t o em erge i n m i d t o l a t e June, peaki ng i n m i d-Jul y . B r eedi ng occurs pri n ci pal l y i n cattail/water-willow ponds. These ponds are often caused by ro ad, railroad, pipeline, power line, and parking lot
constr uct i on next t o natu ral wet l a nd or seepage areas. Adul t s feed pri m ari l y duri ng eveni ng t w i l i ght peri ods on l a rger m a m m a l s si tu at ed i n open pastures or i n tr ansi t i onal habi t a t s (Edm an 1971). B i rds are al so at t acked when th ey are av ailab l e in th e fo rag i n g h ab itat o f th is m o sq u ito

. Coquillettidia perturbans presents unique control problem s because larvae and pupae rem a in attached to
th e base of em ergent pl ant s at th e bot t o m of deep ponds. Oxy g en i s obt ai ned di rect l y from th e pl ant cel l s i n whi c h
th e m odi fi ed ai r tube i s i m bedded. At th i s t i m e th ere i s no known effect i v e l a rval control for Cq . pert urbans ,
m a k i n g ad u lticid in g th e o n l y real ch o i ce fo r co n tro l in resid e n tial areas lo cated n ear cattail m a rsh

. Fo r th is reaso n , th e present pol l u t i on-control fade of cat t a i l ponds mu st be careful l y m oni t o red by m o squi t o -control program s. W h erever possi bl e, m a nm ade cat t a i l drai nage basi ns shoul d be avoi ded or shoul d be so constr uct e d th at , for a p e rio d o f sev e ral week s in late su m m e r, n o stan d i n g water is p r esen t in th e b a sin

. Th is will b r eak th e aq u a tic p a rt o f the life cycle. Coquillettidea perturbans is a vector of EEE, com pounding the probl em of it’s control by increasing the stakes in any decision not to control it. g. Other freshwat e r speci es. M o squi t o es of th e genera Anophel e s and Psorophora can also be pests in Massachusetts. Anophel e s m o squi t o es di ffer from th e other genera of m o squi t o es i n th at , as l a rvae, they lie, upside down, on the under-surface of the water. They com m only inhabit m o re perm anent waters and can

som e t i m es be found al ong th e edges of sl ow-m ovi ng stream s. They are al so fai r l y com m on l a t e r i n th e sum m e r i n puddl es i n di rt roads and other pool s, oft e n bei ng found t ogeth er wi th Ae. vexans and/ or Culex species. Anophel e s

m o squi t o es do not occur i n th e ki nds of swarm i ng num bers th at Aedes m o squi t o es do, but th ey ent e r houses m o re read ily. Th ey o v e rwin ter as ad u lts an d are so m e o f th e first m o sq u ito es to b ite in th e sp rin g . In d i v i d u a l fem a les are
not uncom m on in-house biters on the o ccasional warm day in spring. Psorophora f e rox , i s a l a rge, aggressi ve m o squi t o th at breeds i n th e fl ood pl ai ns of overfl owi ng sum m e r ri vers and stream s. It i s not com m on i n th e north east but , where i t i s present , i t i s an unforget t abl e i n sect , bothbecause of it’s size and the painful bite. B. Habitats in which m o squito control takes place. An underst a ndi ng of where m o squi t o es breed and feed i s essent i a l t o underst a ndi ng m o squi t o control

. Perhaps one of th e m o st frustrat i ng th i ngs t o th e m o squ i t o -control professi onal i s th e m i sunderst a ndi ng wi th i n th e general public as to where m o squito breeding occurs and where m o squito control shoul d take place. To anyone who works i n coast a l m o squi t o control , th e new hom eowner, experi enci ng her fi rst sum m e r brood of sal t m arsh

m o squitoes, is a fam iliar, and som e what sorry, sight. Ca lls concerning, “...that pond of my neighbor’s” are far m o re

com m on th an, “I have som e vernal pool s i n th e wood l o t behi nd m e .” Th e fo llo win g d i scu ssio n will start with b r eed in g areas (co a stal an d in lan d wetlan d s an d , to so m e d e g r ee, surface water bodies) and progress to adult habitats (s urface water bodies, recharge areas, upland areas and ag ricu ltu ral areas). Fin a lly, sen s itiv e en v i ro n m en ts will b e d i scu ssed fro m b o th a b r eed in g p e rsp ectiv e an d with reg a rd to ad u lt m o sq u ito co n tro l. 1

. Co astal W e tlan d s

a. Marin e . Th e m a rin e h ab itat fo r m o sq u ito b r eed in g is restricted to salt m a rsh e s, general l y bet w een th e l e vel of m ean hi gh wat e r and hi gh hi gh t i d e. B e l o w m ean hi gh wat e r t i d al fl ushi ng i s t oo frequent and too strong for m o squitoes to successfully breed and above high high tide the water longer has

su fficien t salin ity to b r eed saltm arsh m o sq u ito es. Th e p l ant species m o st frequently associated with m o squito breeding are the short-form Spartina alterniflora, Spartina patens, and Juncus gerardi i . Tall-form Spart i na

a ltern iflo ra general l y defi nes th e l o wer breedi ng edge (except i n bl ocked di t c hi ng where th e t a l l form edges th e di t c h) and Iva f r uct e sens general l y defi nes th e upl and edge. Aedes cant at or is th e m o st co m m o n sp ecies wh en salin ities are lo w (0 to 1 0 p p t ) as o ccu rs in th e sp rin g an d after heavy sum m e r rains. Aed e s so llicita n s d o m in ates th e m i d

- su m m e r m o n th s wh en salin ities are h i g h (1 0 p p t an d up). However, there is considerable o v e rlap b e tween th e two sp ecies an d it is n o t d i fficu lt to co llect b o th in th e

sam e di p of wat e r. Aedes taeniorhynchus i s l e ss com m on th an above t w o speci es. Cu lex sa lin a r iu s seem s to be
restri ct ed t o rai n -fed pool s at th e upl and edge. b. B r acki s h. B o th Phragmi t e s communi s (tall reed) and Typha species (cattail) obscure the boundary between fresh and salt water. Salin ities in the range of 1 to 5 ppt occur and Ae. cant at or dom inates th is typ e o f h ab itat. Cattail ten d s to in d i cate a fairly co n s tan t so u r ce o f fresh water, su ch as a stream o rsp rin g , wh ilePhragmi t e s t e nds t o i ndi cat e pool i ng of wat e r for t e m porary pe ri ods at a l e vel just hi gh enough t o avoi d sal t

- wat e r influence except under storm conditions. 2. Inl a nd W e t l a nds. Freshwat er wet l a nds vary tr em endousl y i n si ze and hy drol ogy , from sm al l dam p spot s i n i s ol at ed wood lots, to broad wooded swam ps to sheet flow of spring wate r down the sides of hills. Mosquito breeding tends to be

m a xi m i zed i n areas of t e m porary , st andi ng wat e r but th e num ber of speci es th at breed i n freshwat e r m a kes general i zat i ons di ffi cul t at

best

. Red-m a ple swam ps are a significant source of Ae. abserrat u s and Ae. canadensi s . Fl ood pl ai ns, fl ooded

m eadows and shrub swam ps produce Ae. excrucians and Ae. vexans

. Vernal ponds have received particul ar attention both because they breedm o squitoes and because they are an i m port a nt breedi ng si t e for am phi bi ans and other sem i -a quat i c ani m al s. These ponds are rarel y m o re th an oneto-two-hundred square feet in surface area, and rem a in fl ooded from snow m e lt until drydown in m i d to late June. They breeds Ae. abserratus, Ae. excrucians , Ae. canadensis, Ae. cinereus and, i f dry down i s l a t e or th e pool i s refl ooded by rai n , Ae. vexans and Anophel e s speci es. If such a pool i s l o cat ed i n a fl ood pl ai n, i t can breed Ps. ferox as well. Larger, deeper swam ps cause cons iderable difficulty because, although the num ber of m o squito larvae per square foot m a y be l o w th an i n th e vernal ponds, th e si ze of th e swam p m o re th an m a kes up for th e di fference. Further, access to the central areas of the swam p is extrem ely lim ited, m a ki ng aerial application the only practical
control t echni que. Aedes abserratus and Aedes canadensis are two prim ary pest m o squitoes that em erge from these

swam ps. As th e swam ps dry down, i nnum erabl e pocket s of wat e r are l e ft am ong th e tr ee root s and C s . mel anura becom e s increasingly easy to fi nd as th e swam ps dry

. Fl ood-pl ai n m a rshes, wet m eadows and swam ps produce Ae. excrucians i n th e spri ng and Ae. vexans in th e

sum m e r. Fl ood pl ai ns are i d eal l y sui t e d for Ae. vexans as peak fl oodi ng i s del a y e d for a day or m o re aft e r rai n fal l and areas rem a in flooded longer than in other areas. This creates ideal conditi ons for breeding. In the sum m e r East M i ddl esex M C P has recorded up t o 5,000 Aedes vexans per ni ght at

col l ect i on si t e s i n cl ose proxi m i t y t o ri ver fl ood pl ai ns. Shrub swam ps are mu ch less com m on than forested sw am ps so are less a target for m o squito control on that basis. Aedes excrucians seem s t o be th e pest m o squi t o m o st l i k el y t o be found i n such si t e s, and C u . rest uans isalso com m on. The m o squito problem associated with m a rshes de pends on wat e r depth and th e presence of cat t a i l

. A

m a rsh m o re th an a fo o t d eep with an ex ten s iv e stan d o f cattail will b r eed Cq . pert urbans and be a const a nt source of difficulty to control personnel. If wate r levels are lower, and cattail is repl aced by em ergent grasses and rushes, th en Ae. canadensi s and Ae. vexans m a y be present. Again, Culex and Anophel e s species are fairly com m on in this
t y pe of m a rsh. A l e ss-com m on t y pe of wet l a nd i s th e sl opi ng, forest ed wet l a nd caused by wat e r seepage and t y pi cal l y having a ground cover of skunk cabbage. Mosquito breedi ng is not high in such pl aces, the slope preventing significant pooling, but m a nm ad e disturbances, such as cutting a dirt tr ail across the face of the slope, can pool wat e r and provi de breedi ng habi t a t
. 3. Surface W a ter Bodies. As opposed to th e wetlands described above, in which surface water often disappears for at least part of the year, surface wa ter bodies generally have st anding or m oving water yearround and have an extensive, open water surface.

a. Lakes and ponds. Few m o squi t o es breed i n th e open wat e r of l a kes and ponds. B r eedi ng does occur i n th e wet l a nds, part i c ul arl y cat t a i l , th at border th e l a ke or pond. In East M i ddl esex M C P, fl ood pl ai ns and cat t a i l m a rshes l o cat ed on th e edge s of l a kes and ponds produce m a ssi ve popul at i ons of Ae. Excruci ans, Ae. vexans, and Cq . pert urbans (Henl e y , personal com muni cat i on). Sm al l ponds whi c h becom e covered wi th fl oat i ng pl ant s such as duckweed can breed Cu lex territa n s and Anophel e s m o sq u ito es. Sm all,

m a nm ade ponds l acki ng fi sh popul at i ons can al so breed m o squi t o es, especi al l y where em ergent veget a t i on exi s t s . Al though not si gni fi cant breedi ng si t e s, l a kes and ponds are areas where adul t m o squi t o es congregat e. Sev e ral reaso n s p r o b ab l y p l ay a ro le, fro m th e av ailab ility o f water to d r in k , to th e fact th at m a m m a ls an d b i rd s ten d
to com e to water to drink also and, that there are often wetlands im m e diately adjacent to m o re open bodies of water. One i m port a nt poi nt t o m a ke i s th at th ere are num erous t y pes of gnat s and m i dges th at , t o th e untrai n ed observer, l ook mu ch l i k e m o squi t o es. These i n sect s breed i n th e sand or mud edgi ng ponds and l a kes and can gi ve th e appearance of huge num bers of m o squi t o es as th e adul t s swarm am ong th e veget a t i on. Earl y - season com p l a i n t cal l s are oft e n based on observat i ons of th ese, no-bi t i ng, i n sect s. The fauna of al l open bodi es of wat e r, i n cl udi ng ri ve rs and stream s di scussed bel o w, are part i c ul arl y suscept i b l e t o broad-spectrum pest i c i d es such as m a l a th i on and th e py reth roi d s group. Larval control i s rarel y anissue, but adulticiding near open water always carries som e risk of non-target kills. b. R i vers and stream s. The current i n th e open wat e r of ri vers and stream s m a kes

m o squi t o breedi ng i m possi bl e i n al l but th e sl owest m ovi ng sect i ons. Even here th e predat or com p l e x i n m o st cases is to o well d e v e lo p e d fo r m o sq u ito es to su rv iv e in an y num bers. Agai n, however, th e wet l a nds borderi ng th e ri ver are significant breeding sites. Som e breeding also can take place in interm ittent stream s, once they have stopped fl owi ng and before th ey dry down com p l e t e l y . 4. Recharge Areas. Recharge areas are those in which surface water percolates down to recharge aqui fers or drai ns i n t o reservoi rs. The obvi ous concern i n su ch cases i s th at pest i c i d es used i n such areas m a y m ove al ong wi th th e wat e r, causi ng cont am i n at i on of th e aqui fer or reservoi r. The pri m ary pest i c i d es for m o squi t o

co n tro l, resm eth r in an d Bti, b r eak d o w n q u i ck ly an d d o n o t p o s e a water-q u a lity risk to reserv o i rs. Of co u r se, adulticiding over wetlands can kill wetland species direc tly, though ULV rates are low enough that such kills are i n frequent

.
a. W e tland. Because wetlands are wet due to the im perm iability of the substrate, their addi t i on t o recharge areas i s oft e n l e ss th an th at of surrounded, dri e r areas. Pest i c i d es appl i e d t o wet l a nds, therefore, are not likely to cause cont am ination by percolation. However, because wetlands do store water which can then m ove out of the wetland as runoff, pesticides applied to such areas m a y m ove off-site, including into reservoirs. b. Upland. Upland recharge areas rarely have significant m o squito breeding, because the wat e r percol at es downward qui ckl y . The pri m ary concern i n such areas would be heavy rain fall im m e d i ately after a
treatm e n t fo r ad u lt m o sq u ito es. In su ch cases th ere coul d be overl and fl ow of runoff cont am i n at ed by pest i c i d e washed from leaf surfaces. 5. Upland Areas. This is a catch-all category fo r al l l a nds not defi ned as wet l a nds. Obvi ousl y , th e

m a j o rity of hum an developm ents are lo cated on uplands and the m a j o rity of adulticiding takes place within upland areas. Perhaps unconsci ousl y , pest i c i d es used for adul t m o s qui t o control are desi gned t o be rel a t i v el y beni gn t o th e pl ant s and vert ebrat e ani m al s of M a ssachuset t s . No m a t e ri al th at caused robi ns or squi rrel s t o drop i n th ei r tr acks,

o rwh ich k illed m a p l e trees, wo u l d ev er b e p e rm itted fo r u s e in Massach u s etts. Th is m a k e s ULV sp rays in su ch areas appear reasonably benign. Howeve r, sim p ly because the larger species do not exhibit acute effects, does not

m ean th at no effect s occur. One cl ear quest i on th at ca nnot be answered i s what l ong-t e rm effect s do regul aradulticide treatm e nts have on the le ss-visible fauna of the typical s uburban woodlot-m eadow habitat in M a ssachuset t s . 6. Agri cul tu ral Areas. The muddy hoof-pri nt s of th e m i l k cows around th e wat e r hol e m a y wel l breed Ae. vexans , but th e proper control i n such cases mu st t a ke i n t o account th e fact th at food for hum an

consum pt i on i s th e pri m ary purpose of th e l a nd i n quest i on. The B t i and IGRl a rvi c i d es current l y avai l abl e are unlikely to cause problem s in m eat, dair y or crop production, but adulticides are a different story. Pesticide residues are l i m i t e d even on non-organi cal l y grown produce and a l a t e -sum m e r appl i cat i on has th e pot ent i a l t o cause probl em s for growers. Of part i c ul ar concern are t h e backy a rd gardens of hom eowners whi c h cannot hel p but receive the drift from pesticide applications. Ag ricu ltu ral en terp rises o f p a rticu l ar concern are apiaries and organic farm s. Bees are susceptible to pest i c i d es but th e exposure t o bees caused by m o squi t o cont rol appl i cat i ons of resm ethri n at ni ght i s m i ni m a l si nce the bees have already retu rn ed to th eir h i v e s. During the EEE vector control aerial applications of m a lathion, beekeepers were advised to cover their hi ves. The appl i cat i ons were schedul ed for 2.5 hour wi ndows aft e r dawn and before dusk. The cri t e ri a used i n det e rm i n i ng th e peri od of th e spray wi ndow i n cl uded day l i ght peri ods when m o squi t o act i v i t y woul d be opt i m al and bee act i v i t y woul d be m i ni m a l

. The owners of properl y run organi c farm s have gone t o great l e ngths t o becom e cert i f i e d as pest i c i d e free. In m o st cases the farm s are sm all and the business, at leas t in th e first years, m a rg in al. Th e p r o b l em with o r g a n i c farm s, under norm a l ci rcum st ances, i s knowi ng th ey exi s t , not avoi di ng th em once known. M a ssachuset t s M C Ps have system s in place so that organic farm ers can heave their land excluded from pestic ide applications. Problem s can devel op when th e quest i on of dri f t from nui sance spra ying occurs, or when there is a p u b lic-h ealth th reat. 7. Sensitive environm ents and populations. Certain e nvironm ents and popula tions have special consi d erat i ons whi c h requi re a m o re caut i ous approach t o m o squi t o control

. Som e of th ese have been di scussed above but th ere are others worthy of m e nt i on.

a. Urban. The urban envi ronm ent requi res speci al care due t o th e i n creased popul at i on densi t y and th e di ffi cul t y i n ensuri ng th at peopl e know th e benefi t s and th e dangers associ at ed wi th m o squi t o control

. b. R ecreat i on. Peopl e who enjoy out door recreat i on areas oft e n have a hi gher
t o l e rance for m o squi t o es and a l o wer t o l e rance for spray ve hi cl es th an does th e popul at i on at l a rge. On th e otherh a n d , reso rt co m mu n ities m a y d e m a n d h i g h e r th an n o r m a l lev e ls o f m o sq u ito co n tro l in o r d e r to m a k e th eir site

m o re enjoyable to the public. In any event, areas in which sum m e r recreation takes place tend to polarize the debate

o v e r co n tro l an d p r o v i d e in creased p o litical h ead ach es fo r MCPs, ev en wh ere m o sq u ito co n tro l itself is relativ ely straightforward.

c. Sensitive individuals. There are severa l groups of people who are sensitive to pesticide appl i cat i ons. Som e i ndi vi dual s wi th em phy sem aor asth m acan be adversely affect ed by ai rborne pest i c i d e appl i cat i ons and such i ndi vi dual s som e t i m es reque st th at th ei r propert y be excl uded from spray i ng. In d i v i d u a ls with Mu ltip le Ch em ical Sen s itiv ity (MCS) h a v e co n t acted MCPs an d req u e sted ex clu s io n fro m spraying. No project has reported diffi culty working with these individuals to create acceptable no-treatm e nt zones. The causes, sy st em s, di agnosi s , and tr eat m e nt of M C S al l rem a i n i n a great st at e of fl ux, so M C Ps are wel l advi sed
t o work careful l y wi th M C S i ndi vi dual s and pay at t e nt i on t o th e changi ng m e di cal knowl e dge concerni ng M C S. d. Publ i c and Pri v at e W i l d l i f e R e fuges and Conservation Areas. These areas are often excluded from m o squito control at the re quest of the property owner because m o squito control runs counter to the goal of preserving the area in as natural a state as possi bl e. Excl usi on i s not al ways absolute, however, as

so m e tim es en v i ro n m en tally frien d l y p e sticid es lik e Bti can be used or wat e r m a nagem e nt m a y be pract i ced where p e sticid e ap p licatio n s are n o t p e rm itted

. Th e b e st way to ap p r o ach su ch areas is to co n t act p r o p e rty o w n e rs an d d i scu ss with th em p o ssib l e m o sq u ito -co n tro l altern ativ es.

e. AC EC and areas wi th rare or endangered sp ecies. W h enever rare or endangered species are p r esen t, p e sticid e ap p licatio n s an d/ o rwetlan d alterati ons need t o be approved by th e appropri a t e agenci es (see discussion under Rare and Enda ngered Species under im pacts of physical control below). In m a ny cases they will be reject ed out of hand. f. W a ter supplies. As stated above under surface water bodies and recharge areas, open wat e r and wat e r th at i s dest i n ed for dri nki ng suppl i e s, wh ether th rough percol at i on i n t o th e groundwat er or by fl ow i n t o reservoi rs, mu st be very careful l y prot ect ed. Fortunat e l y , it is rare in d eed th at water su p p lies are h e ld in su ch a way as to b r eed m o sq u ito es. Fo r water su p p lies in g e n e ral, th erefore, m o squi t o control mu st consi s t of i n fl uenci ng th e desi gn of such sy st em s t o avoi d creat i ng habi t a t s th at woul d produce m o squi t o es. C. Mosquitoes as Disease Vectors Mo st o f th e 9 o r g a n i zed m o sq u ito co n tro l p r o j ects in Massach u s etts j u stify th eir activ ities (an d claimbenefi t s ) i n part on th e di sease th reat t o hum an and ani m al popul at i ons posed by vect or m o squi t o es. C ontrol program s i n B e rkshi r e C ount y and C a pe C od (Fi g . 1) l i e out si de of th e area hi st ori cal l y affect ed by out breaks of Eastern equine encephalomy elitis (EEE) a nd therefore do not justify or plan th eir program s to address this disease probl em . Dog heart w orm i s recogni zed th roughout th e C o m m onweal th (Arnot t & Edm a n 1978). C a l i f orni a group viruses have also been found in m o squitoes. To date hum an illness attributable to these agents has not been id en tified in Massach u s etts.. A m a jor pract i cal di ffi cul t y i n addressi ng th e vect or m o squi t o probl em i n M a ssachuset t s st em s from th e fact th at th e speci fi c speci es responsi b l e for tr ansm i ssi on of di sease agent s t o hum ans and dom est i c ani m al s are often unknown. The enzootic vector of EEE am ong birds is clearly Cs

. mel anura , but th e vect or(s) t o horses and hum ans i s unknown. The cat t a i l m o squi t o , Cq . p ert u rbans , and th e m o st com m on refl ood speci es, Ae

. vexans , are prim e suspects. Other m a m m a l-feeding Aedes such as Ae

. canadensi s al so m a y be i nvol ved and perhaps even Cs

. mel anura feeds suffi ci ent l y on m a m m a l s under unusual ci rcum st ances t o cause som e tr ansm i ssi on t o th ese dead-end host s (Nasci & Edm a n 1981a). B a sed on i s ol at i ons i n other st at es (C al i s her & Thom pson 1983) and a few i n M a ssachuset t s (W al ker 1984), i t seem s l i k el y th at th e i m port a nt C a l i f orni a group vi ruses i n th e Northeast , i

. e. LaC r osse and Jam e st own Can y o n , are tran sm itted b y th e treeh o l e m o sq u ito , Ae

. triseria tu s , and spri ng, woodl and Aedes , respectively. Dog heart w orm al so m a y be spread pri m ari l y by spri ng Aedes but refl ood Aedes (e.g., Ae

. sticticu s and Ae

. trivitta tu s ), Cq pert urbans, C x . sal i nari u s and Anophel e s spp. al so m a y be i nvol ved i n tr ansm i ssi on of th i s parasi t e (Arnot t & Edm a n 1978). 1

. Eastern Eq u i n e En cep h a litis MCP' s in Southeastern Massachusetts, i.e., Norfolk, Bristol and Plym outh Counties, face the greatest threat fro m th is d i sease. Du rin g m a j o r ep id em ic years, v i ru s activ ity ex ten d s n o r th ward fro m th is en zo o tic fo cu s in to southern New Ham p shi r e and west ward i n t o R hode Isl a nd, C onnect i c ut and C e ntral M a ssachuset t s . Al l project s except Berkshire County give considerab le continuing attention to this poten tial problem . Upon occasion, projects

m a y subm it m o squitoes to the SLI for EEE virus analysis. The enzootic foci of EEE are red m aple/white cedar swam ps. The larges t adult populations of the enzootic vector, Cs

. mel anura , occurs in or near the locali zed swam ps where th i s speci es devel ops. M o st hum an and horse cases also o ccu r in th e im m e d i ate v i cin ity o f th ese sam e swam p h ab itats. Still, at tim es th is m o sq u ito m a y d i sp erseseveral m i l e s from i t s l a rval habi t a t (M orri s et al . 1980. Nasci 1980. Nasci & Edm a n 1984) and hum an/ horse cases occasionally occur in upland areas. This m o squito is unusual in that it overwinters in th e larval stage (4th or 3rd in star). Ad u lts fro m th is g e n e ratio n em erg e in late sp rin g (i.e., m i d to late May). Two to th ree su m m e r g e n e ratio n s occur about one m onth apart , e.g., i n l a t e June, Jul y a nd August , dependi ng on wat e r l e vel s and t e m p erature (Nasci 1980). EEE virus is generally not isolated from this m o squito until late sum m e r. During epidem ic years it tends to be i s ol at ed earl i e r, i

. e., begi nni ng i n earl y Jul y , but a

pparent l y never from th e overwi n t e ri ng generat i on. The lo catio n o f th e v i ru s fro m No v e m b er to Ju ly rem a in s a my stery. Cu liseta mel anura feeds onl y aft e r dark and th e vast m a jori t y of bl ood m eal s are obt ai ned from passeri ne bi rds (Nasci & Edm a n 1981a). Thi s sy l v an m o squi t o feeds equal l y at ground l e vel and at hi gher el evat i ons i n th e tr ee canopy . Act i v i t y i s concentr at ed just aft e r dark and just before sunri s e (Nasci & Edm a n 1981b). The m o rni ng fl i ght act i v i t y peak does not seem t o i nvol ve b l o o d -feed in g b u t rath er th e retu rn to su itab l e d a ytim e restin g sites. The isolation of EEE virus from the cattail m o squito Cq

. pert urbans duri ng di sease out breaks (C rans, personal com muni cat i on) has focused suspi c i on on th i s speci es at th e m o st l i k el y epi d em i c vect or t o horses and hum ans. Ae

. vexans and Ae

. canadensi s are two other prim e suspects for EEE virus transm ission to hum ans and horses i n M a ssachuset t s . Li ke Cq

. pert urbans , they are m a jor pests. Their bi ologies will be described along with the other pest species. A new EEE threat m a y be de veloping in New England as Ae. so llicita n s , l ong a known vect or i n New Jersey (Crans et al. 1991), was, for the first tim e, found to be EEE-positive in Connecticut in 1996 (Andreadis 1996). Crans (1991) gave a suggest ed cycle for EEE transm ission to Aed e s so llicita n s in wh ich C s . mel anura i n fect ed ni ght -roost i ng gl ossy i b i s , whi c h were th en fed upon by Ae. so llicita n s wh ile feed in g in th e salt m a rsh

. Though th e l i nk bet w een gl ossy i b i s and Ae. so llicita n s i s t e nt at i v e, th ere can be no quest i on th at Ae. so llicita n s is a pot ent vect or i n New Jersey and coul d be an im p o r tan t v ecto rin Massach u s etts as well. 2

. Califo r n i a en cep h a litis v ecto r s Jam e st own C a ny on vi rus has been i s ol at ed from both dark-l egged a nd banded-l e gged spri ng Aedes in M a ssachuset t s and nei ghbori ng New York St at e (W al ke r 1984, C a l i s her & Thom pson 1983). LaC r osse vi rus i s associated with th e tree-hole species Ae

. triseria tu s i n East ern New York St at e, but i t

has not y e t been found i n Massachusetts. All suspect hum an cases of arboviral diseas e which are found not to be EEE are sent by the SLI to
th e C D C for a ful l arbovi rus anal y s i s . No C a l i f orni a Group vi rus i n fect i ons have been i d ent i f i e d.3. Dog heart w orm A wid e v a riety o f m o sq u ito sp ecies are cap ab le o f v ecto r in g th is d e b ilitatin g n e m a to d e p a rasite o f can in es. Coin lesions in hum an lungs can o ccur from accidental infection with this parasite (Adkins & Dao 1984, Deren & Feinberg 1984). Felines are m o re suscep tible to infection than was previous ly thought because th ey apparently do
not produce m i crofi l a ri a (Fukushi m aet al . 1984). Natu ral i n f ect i ons have been found i n th ree di fferent speci es of spri ng Aedes i n M a ssachuset t s but other pot ent i a l vect ors cannot be di scount ed (Arnot t & Edm a n 1978). The
tr eehol e m o squi t o , Ae

. triseria tu s , and three perm anent water species, Cx. sa lin a r iu s , An. punct i p enni s and An. quadri m acul at us , are all possible late season vectors. Ki ng and M unro (1989) report e d on a quest i onnai r e se nt t o Pl y m outh C ount y vet e ri nari ans concerni ng dog heart w orm . Infect rat e s were report e d as general l y l e ss th an 5% but one vet e ri nari an report e d rat e s above 20%. W i th bet w een 25,000 and 30,000 dogs i n th e report i ng area, th e est i m at ed cost of y earl y prevent a t i v e tr eat m e nt s was $750,000.V. CURRENT ABATEM ENT STRATEGIES AND THEIR IM PACTS

A. Chem ical Control 1. Overview of Chem ical Control

a. Gen e ral To x i city o f Pesticid es. Pesticides are placed in one of four categories ba sed on their acute toxicity (Table 13). Category I pest i c i d es are extr em el y t oxi c whi l e C a t e gory IV m a t e ri al s can range from m i l d l y t oxi c t o non-t oxi c. Pesticides are also classified as either “General Use” or “Restricted Us e” m a terials. Gen e ral Use p e sticid es are avai l abl e for use ei th er by th e general publ i c or by l i censed applicators. Restrict ed Use m a terials m a y only be appl i e d by cert i f i e d appl i cat ors or l i censed appl i cat ors worki ng di rect l y under th e supervi s i on of a cert i f i e d applicator. W h ile Restricted Use m a teri al s are general l y m o re t oxi c th an General Use ones, t oxi ci t y i s not th e onl y issue. For exam ple, resm ethrin-based ULV products (Scour ge) have recently been placedon the Restricted-use list,
not so mu ch because of toxicity but because the m ode of application (U LV area-wide treatm e nts) m eans that i n correct appl i cat i ons can have wi de-rangi ng effect s.

Tabl e 13. Toxi ci t yC a te goryof Pestci des used i nM o squi t o C ont rol C a t e gory Si gnal W o rd C a t e gori e s of Acut e Toxi ci t y Probable Oral Antidote Statem ent R e qui red on LD 50 LC 50 Leth al Dose Other C a ut i ons a th e l abel Oral Derm al Inhal a t i on for 150 l b . m a n m g /kg m g /l I DANGER 0 th ru 50 0 th ru 200 0 th ru 0.2 A few drops Skul l and Crossbones Hi ghl y Toxi c 

## 1 t o a t easpoon- “C al l Phy s i c i a n Im m e - POISON ful diately ” Antidote Statem ent II W A R N ING from 50 from 200 from 0.2 >1 t easpoonful M oderat e l y th ru 500 th ru 2000 th ru 2 t o one ounce Toxi c III CAUTION from 500 from 2000 from 2.0 >1 ounce Sl i ght l y Toxi c th ru 5000 th ru 20,000 th ru 20 t o one pi nt or one pound IV C AUTION >5000 >20,000 >20 Over one pi nt R e l a t i v el y or one pound Non-t oxi c a All pesticide labels are required to include th e statem ent, “Keep out of reach of Children.” from : pest i c i d e Appl i cat or Trai ngi ng C o re M a nual : Northeast e rn R e gi onal Pest i c i d e C oordi nat o rs and M a nual 2, Vect orborne Di sease C ontrol Hom e study C ounrse 3013-G: C e nt er for Di sease C ontrolNewer pest i c i d es have muddi ed th e pest i c i d e cl assi fi cat i on sy st em . B t i and Bacillus sphaericus are bi ol ogi cal organi sm s y e t th ei r m ode of act i on i s th rough th e creat i on of a t oxi n th at i s act i v at ed i n th e i n sect ’s

m i dgut . For th e purposes of pest i c i d e cl assi fi cat i on and th i s GEIR , th erefore, th ey are consi d ered pest i c i d es, not bi ol ogi cal control agent s . M e thoprene i s al so a case of a m a t e ri al (an i n sect growth regul at or) th at , whi l e not di rect l y t oxi c, so al t e rs th e l i f e cy cl e of th e i n sect th at death resul t s . Agai n, m e thoprene (Al t o si d) i s cl assi fi ed as a pest i c i d e but i s far rem oved from th e cl assi c chl o ri nat e d hy drocarbon and organophosphat e pest i c i d es of th e past
. b

. Pesticid es u s ed fo r Mo sq u ito Co n tro l In Massach u s etts Twent y -si x di fferent i n sect i c i d e formul at i on di stri but ed am ong fi ft een product l i n es were used for

m o squi t o control i n M a ssachuset t s bet w een 1993 and 1995 (Tabl e 14). Ei ght of th ese formul at i ons used B t i as th e active ingredient, five were m e thopren e-based, three were resm ethrin-based , two each were pyrethin-based or

m a lathion-based, and there were one each of tem e phos, isocte decanol, and m i neral oil. Of these, Acrobe (Bti) and Vectobac AS (replaced by 12AS) are no longer produced . Arosurf-MSF (Isoctadecnol ) was rem oved from the

m a rket but has just reappeared under th e nam e Agni que M M F . Abat e 4E was not used i n ei th er 1994 or 1995 and both th e M a l a th i on 10EC and th e R e sm ethri n product (E PA rep # 4-339-53853) were used i n sm al l am ount s onl y (Tabl e 4 gi ves a break-down by Project of chem i cal use). Of th e in secticid es u s ed , all o f th e larv icid es were classed as Categ o r y IV m a terials b y EPA. Bo n i d e M o squito Larvicide, available but not used, is borde r line between Category III and IV. VectoLex CG, a new Bacillus sphaericus product, is Category IV. All a dulticides are in Category III. M a ny pest i c i d es have dual act i ons. They are i m port a nt i n control l i ng i n juri ous pest s, but th ey m a y al so present a hazard to species not considered to be pests in the environm ent. As a result, the concepts of "target” and "non-t a rget ” organi sm s have ari s en. For exam pl e, i n m a ny freshwat e r sy st em s, control m easures m a y be t a ken agai nst undesi rabl e t a rget organi sm s such as m o squi t o l arvae or unwant e d al gae. Non-t a rget organi sm s are those whose destruct i on i s not i n t e nded but whi c h m a y be affect ed. These non-t a rget organi sm s m a y pl ay key rol e s i n aquatic ecosystem s. The distinction between target a nd non-target species is not absolute, because the sam e group m a y be nont a rget organi sm s i n one area of th e country but t a rget organi sm s, under cert a i n ci rcum st ances, i n another area. For

exam pl e, l a rvae of caddi sfl i e s (Tri chopt era) and nai a ds of m a y f l i e s (Ephem e ropt era) are i m port a nt food sources forTabl e 14. C h em i cal s used i n M a ssachuset t s m o squi t o control , 1993 th rough 1995 Trade Nam e EPA Registration Ac tiv e % Activ e To x i city Oth e r Num b er Ingredi e nt (s) Ingredi e nt C l ass W a rni ng St at em ent s LARVICIDES Abat e 4E 241-132 Tem e phos 43 IV Acrobe a62637-1-241 B t i b IV Arosurf-M SF c 42943-8 Isooctadecanol 100 III Alto sid B r i quet s 2724-375-64833 M e thoprene 7.9 IV XR B r i quet s 2724-421-64833 M e thoprene 1.8 IV Pel l e t s 2724-448-64833 M e thoprene 4.0 IV Bactim o s B r i quet s 43382-3 B t i 10 IV Granul es 37100-43-2217 B t i 0.2 IV Pel l e t s 37100-42-2217 B t i 0.4 IV GB -1111 8898-16 Petr ol eum Hy drocarbons GB -1356 8898-16 Teknar HP-D 2724-365-64833 B t i 0.8 IV Vectobac AS 275-52 B t i IV 12AS 275-66 B t i 1.2 IV Granul ar 275-50 B t i 0.2 IV ADULTICIDES M a l a th i on 8EC 34704-119 M a l a th i on 8 III Perm anone 10EC 4816-688 Perm ethri n 10 III Perm anone 31-66 4816-740 Perm ethri n 31 III Resm ethri n 4-339-53853 Resm ethri n III Scourge 4+12 432-716 Resm ethri n 4 III ⎫ ⎧ RESTRICTED USE PB O 12 ⎬ ⎨ CLASSIFICATION Scourge 18+54 432-667 Resm ethri n 18 III ⎪ ⎪ Du e to acu te fish to x i city PB O 54 ⎭ ⎪ R e t a i l sal e t o and use onl y by ⎪ C e rt i f i e d Appl i cat ors or ⎪ persons under th ei r di rect ⎪ supervi s i on and onl y for those ⎪ uses covered by th e C e rt i f i e d ⎩ Applicators Certificate MATERIALS REGISTERED BUT NOT USED - LARVICIDES Alto sid Li qui d 2724-392-64833 M e thoprene 5 IV Li qui d C on 2724-446-64833 M e thoprene 20 IV B oni de M o squi t o Larvi c i d e 4-195 M i neral Oi l 98 III-IV Vect oLex C G 275-77 B. sphaeri cus 50 d IV MATERIALS REGISTERED BUT NOT USED - ADULTICIDE Fy fanon ULV 4787-8 M a l a th i on 95 III a No l onger m a rket ed b Ba cillu s th u r in g i en sis var . israelensis c Now m a rketed as Agnique MMFtr out and other val u abl e freshwat e r fi sh. In cert a i n areas, these species of insects can occur in such large num bers
th at th ey becom e nui sance pest s, and th ei r i m m a tu re st ages are th e t a rget of pl anned control operat i ons wi th p e sticid es. The i d eal si tu at i on i n m o st control operat i ons i s t o be abl e t o destroy th e undesi rabl e speci es at pest i c i d e

co n cen tratio n s th at will h a v e m i n i m a l ad v e rse effects o n th e rest o f th e b i o t a. Ho wev e r, so m e d e g r ee o f
contam ination and hazard is assum e d with nearly all pes ticide use. The hazard to aquatic organism s and other wi l d l i f e speci es depends on th e chem i cal and phy si cal proper ties o f th e p e sticid e, typ e o f fo rmu l atio n , rate an d

m e thod of application, and characteristics of the receiving ecosystem system (Nim m o 1985). Looking at the change in pesticide use by MCPs over the past decade (Tab le 3), all Category II insecticides have been phased out and M e thoxy cl or, th e onl y organochl ori n e com pound on th e l i s t i n th e earl y ei ght i e s, has l i k ewi s e been dropped. Usi ng m a l a th i on and perm ethri n for l a rvi c i d i ng has al so been di scont i nued and B t i and

m e thoprene have taken over from Mineral Oil (Flit-MLO) as the dom inant larvicides. Fo r adulticiding, perm ethrin and resm ethrin have essentially repl aced m a lathion. Theses changes indi cate that MCPs have responded to the desi re of th e publ i c at l a rge (i ncl udi ng th e st aff of th e M C Ps in cid e n t ally) fo r m a terials with th e lo west risk s. Th e

o th e r co n c lu sio n to b e d r awn is th at, u n til th e d i sco v e ry o f n e w m a terials, b o th ad u lticid in g an d larv icid in g are present l y be conduct e d wi th th e m a t e ri al s th at have th e l eas t overal l ri sk. Advances i n reduci ng th e ri sk of chem i cal

use mu st th erefore com e from i m proved t a rget i ng and i n creas ed use of wat e r m a nagem e nt and/ or bi ol ogi cal control
t echni ques.

c. General Propert i e s of R e gi st ered M o squ i t o C ontrol Insect i c i d es i n M a ssachuset t s , 1996. Physical Properties . Usin g b o th water so lu b ility an d Ko W , th e fo llo win g in secticid es are classified as water insoluble or practically water insol uble; Bti, isooctadecanol, m e thoprene, petroleum oil/Flit MLO, pyrethrin I,

resm ethrin and tem e phos. Malathion is the m o st water sol uble insecticide used (145 ppm ). Nevertheless, it still has a relatively high partition coefficient (K oW 779) and because of its rapid envi ronm ental and m e tabolic degradation is not expected to bioaccumu late in any appreciable fashion as discussed below. In secticid es wh ich h a v e little o rn o v o l atility are; Bti, B. sphaeri cus, m a l a th i on, m e thoprene, and t e m e phos. Isooctadecanol and m i neral oil are slightly volatile. A lthough pyrethrin I and resm ethrin have appreciable vapor pressures, th ey are m o st l i k el y t o be bound t o suspended organi c m a t t e r or soi l part i c ul at e i n natu ral sy st em s. If volatilization occurs, they are rapidly photodegraded.Fo u ro f th e in secticid es h a v e v a p o rd e n s ities less th an 1

. 0 (relativ e in d e x to air) an d so co u l d co n cen trate near the surface, resulting in increased exposure via inhalation. Howe ver due to the low vapor pressure of i s ooct a decanol and m e thoprene, th ese com pounds are m o t l i k el y t o be avai l abl e for concentr at i on. The py reth roi d i n sect i c i d es, as di scussed above, are rapi dl y degraded by phot ol y s i s i f th ey becom e avai l abl e whi c h i s not l i k el y from environm ental surfaces. For speci fi cs on a gi ven i n sect i c i d e, th e reader shoul d refer t o th e sam p l e l abel s and M a t e ri al Safet y Dat a Sheet (M SDS) for that m a teri al , l o cat ed i n Appendi x C

. Anal y t i cal M e thodol ogy (from : The Pesticide Manual 7th ed. W o rthing & W a lker, British Crop Protection C ounci l

. Lavenham , UK. 1983. For m o re det a i l e d m e thods consul t The Agrochem i cal Handbook, 2nd ed. 1983). 1. B t i and B. sphaeri cus are m easured i n i n t e rnat i onal t oxi ci t y uni t s /m g product (i .u.) rel a t i v e t o th at of an appropri a t e st andard product agai nst Tri c hopl usi s ni or Aedes egypti i n st andard bi oassay s . Assay s based on th e num ber of spores are not sat i s fact ory . 2. M e thoprene i s anal y zed by GLC or HPLC w/UV det ect i on. 3. Isooct a decanol i s anal y zed by GLC

. 4. Pyrethrin I is analyzed by GLC. 5. Resm ethrin is analyzed by GLC. 6. Tem e phos i s anal y zed by GLC

. 7

. Malath io n is an alyzed b y GLC. 8. Petroleum Oil is analyzed by GLC. Transport , Persi s t e nce and Degradat i on i n Soi l , Ai r and W a t e r . No n e o f th e in secticid es u s ed fo r m o sq u ito co n tro l in Massachusetts are included on the 1987 EPA lists (I + II) of the 51 priority pesticide leachers. Sy nergi s t s and Inert s i n Pest i c i d e Product s . Synergists are com pounds added to a pesticide that in crease the efficacy of that pesticide. Relatively few

com b inations of insecticides and synerg ists lend them selves to practical use, either because the degree of im proved perform ance is sm all or because too mu ch of the expensiv e synergist is required, or both (Casida 1970). By the

sam e token, no exam ple of increased t oxicity to m a n or useful anim als under practical conditions has been reported (Hay es 1982).In m o squi t o control , th e sy nergi s t i c effect of va ri ous com pounds on py reth rum and sy nthet i c py reth roi d s i s wel l known. pi perony l but oxi de (PB O ) i s th e sol e sy nergi s t used i n M a ssachuset t s . It act s as a substr at e for th e

m i crosom al enzy m e -NADPH2 sy stem , which also m e tabolizes m a ny drugs and insecticides. By serving as an al t e rnat i v e substr at e for th e det oxi fi cat i on enzy m e of th e i n sect , PB O prol ongs th e persi s t e nce of th e i n sect i c i d e so that a lower initial dose is effective (Casida et al. 1966, Kam i enski & Casida 1970, Casida 1970). “Inert” m a terials which are used as fo rmu l atio n aid s in th e in secticid es ap p lied b y to wn s/BOHs an d Project s for m o squi t o control i n M a ssac husetts are categorized as follows: Powd ers, granular carriers, solvents and special effects m a terials. Dust abl e powders general l y cont ai n l

- l 0 % a.i

. m i xed wi th powdered m i neral s as carri ers and di l u ent s . For wetable powders, the sam e diluents and carriers can be used as for dust s . However for di spersi bl e powders, a fi ner particle-size spectrum is necessary , the proportion above 40 um not exceed ing a few percent. No powdered

m a terials are cu rren tly in u s e in m o sq u ito co n tro l in Massach u s etts. Granul ar formul at i ons are m a de by ei th er i m pregna t i on (soaki ng or coat i ng) of granul ar carri ers or by granul at i on of powdery m i xtures of act i v e i ngredi e nt a nd formul at i on ai ds. These t w o t y pes di ffer i n th e act i v e i ngredi e nt concentr at i ons at t a i n abl e . For both t y pes, an act i v e i ngredi e nt cont ent of 20% i s th e m a xi mu m t echni cal l y feasi b l e . Incl uded i n th e groupi ng are B act i m os bri quet s , granul es and pel l e t s (B t i ) , Vect obac granul es (B t i ) and Al t o si d bri quet s , XRbri quet s , and pel l e t s (m ethoprene). Li qui d formul at i ons such as emul si fiable concentrates, soluble concen tr at es and ULV use vari ous organi c sol v ent s as di l u ent s . Al i phat i c hy drocarbons are poor sol v ent s for m o st act i v e i ngredi e nt s and are th erefore

norm a l l y onl y used for very di l u t e formul at i ons. Arom a t i c hy drocarbons are used frequent l y , th e fract i ons C 6 t o C1 2 b e in g fav o r ed (e.g ., fro m tech n i cal x y len e m i x tu r es to su b s titu ted n a p h th a len e s). Ap art fro m th e to x i city o f b e n zen e, th eir h i g h flam m ab ility p r o h i b its th e u s e o f lo wer aro m atics. On th e o th e r h a n d , p h y to to x i city freq u e n tly i n creases wi th i n creasi ng m o l ecul a r wei ght . Ket ones are excel l e nt sol v ent s for m a ny organi c com pounds. M o st of th em are at least p a rtially water so lu b l e, so th ey are m a in ly su itab l e fo r fo rmu l atin g water-so l u b l e an d liq u i d

- activ e ingredients. W h en they are used fo r th e formul at i on of emul si fi abl e con centrates of solid, water-insoluble active i ngredi e nt , th e act i v e i ngredi e nt oft e n cry s t a l l i zes out duri ng th e preparat i on of th e spray m i x. Thi s i s caused by th e sol v ent passi ng i n t o th e aqueous phase whereupon th e act i v e i ngredi e nt i s preci pi t a t e d i n th e "oi l dropl et s" of th e

emul si on. Here ket ones can norm a l l y onl y be used t ogeth erwith o th e r, water-in s o l u b l e so lv en ts as co so lv en ts.Thi s i s al so val i d for al cohol s and gl y c ol s and th ei r ethers and est e rs as wel l as for hi ghl y pol ar aprot i c sol v ent s such as di m e th y l sul f oxi de and di m e th y l form am i d e. C h l o ri nat e d sol v ent s are onl y used t o a very sl i ght ext e nt
. Chlorobenzene is used occasionally; di chlorm ethane is used m o re frequen tly as a relatively non-toxic, highly volatile, and nonflam m able solvent for hygiene a nd stored-product agents and for aerosols. Emu l sifiab le co n cen trates u s ed fo r m o sq u ito co n tro l in clu d e th e larv icid e Ab ate 4 E an d th e ad u lticid es M a l a th i on 10EC , Perm anone 10EC , Perm anone 31-66, R e sm ethri n , and th e Scourge product s . W ith increasing public concern of off-site deposition of pesticides (e.g. aerial drift) and the m ovem e nt of
th e pest i c i d e i ndustr y away from organi c com pounds t o bi ol ogi cal i n sect i c i d es, new formul at i on t echnol ogy has

em erged. Fl owabl e concentr at es not onl y reduce dri f t , but provi de bet t e r coverage and great er adhesi on t o th e substr at e. Dri e d act i v e i ngredi e nt s are ground t o a uni form part i c l e si ze (usual l y 10 um ) as ei th er a dry , wet (H 2 O) or oi l suspensi on (whi ch th en i s di l u t e d wi th wat e r for appl i cat i on). Incl uded i n th i s groupi ng are th e B t i product s Teknar fl owabl e (B t i ) and Vect obac AS and 12AS. None of th e di rect nerve t oxi ns (py r ethri n and resm ethri n ) have i n ert i ngredi e nt s whi c h appear on EPA/ SAP Li st 1. Scourge (resm ethri n ) cont ai ns a Li st 2 com pound (0.025% xy l e ne) and 4-12% PB O and 12% Chevron 100 (a soybean o il diluent) as additiona l active ingredients. None of th e i ndi rect nerve t oxi ns (m al athi on and t e m e phos) have i n ert i ngredi e nt s whi c h appear on th e EPA/ SAP Li st 1. Of th e product s whi c h cont ai n m a l a th i on, m a l a th i on 57% EC cont ai ns a Li st 2 com pound, 31.5% and 36.55% xy l e ne range arom at i c s, respect i v el y . Tem e phos (Abat e 4E) cont ai ns 39% C h evron 100 as an ad d itio n a l activ e in g r ed ien t
. None of th e sel ect i v e i n sect t oxi ns (B t i and m e thoprene) cont ai n any Li st 1 or 2 com pounds. No other ad d itio n a l activ e in g r ed ien t s are listed

. None of th e phy si cal t oxi ns (i soocadecanol (Arosurf M SF/Agni que M M F and petr ol eum oi l s ) cont ai n any of th e Li st 1 or 2 com pound. Petr ol eum hy drocarbons as a group are i n cl uded on Li st 2 as pot ent i a l t oxi c i n ert s of pest i c i d e product s .d. Pest i c i d e Handl i ng and Appl i cat i on Pest i c i d e st orage vari es consi d erabl y from project t o project . C a pe C od uses onl y bagged B t i so no formul at i on work i s necessary nor are th ere stri ngent st orage requi rem e nt s. Fi ve project s st ore and formul at e chem icals in an area within th e m a in g a rag e , g e n e rally sep a rated b y a wire cag e (cab in ets with in a m e tal sh ed at Suffolk) from the m a in garage area. Ventilation fans operate either continuously or whenever the lights in the garage are tu rned on. B r i s t o l , C e ntral M a ss and Essex al l have separat e bui l d i ngs for pest i c i d e st orage and fo rmu l atio n . Cen tral Mass m e n tio n e d th at th eir stru ctu r e was b u ilt in co n s u ltatio n with th e lo cal fire d e p a rtm e n t an d the State Pesticide Board. East Middlesex constructed its storage area from Departm e nt of Defense specifications. All projects use pickup-truck m ounted ULV sprayers for adulticiding. No therm a l foggers rem a in in use. Backp ack sp rayers are u s ed to ap p l y liq u i d larv icid es an d , in so m e p r o j ects, ad u lticid es. Gran u l ar m a terials are appl i e d by hand or wi th cy cl one-t y p e spreaders. B r i quet formul at i ons are appl i e d by hand. Addi t i onal i n form at i on on th e pest i c i d es m a y be found on th e sam p l e l abel s and M S DS sheet s i n Appendi x C

. Appl i cat or cert i f i cat i on i s done by th e Pest i c i d e B u reau of th e Depart m e nt of Food and Agri cul tu re. Mosquito control applicators are certified under the “Mosquitoes and Biting Flies” subcategory of “Public Health and Nui s ance C ontrol ” . Aeri al Appl i cat ors are l i cense d separat e l y . Ongoi ng tr ai ni ng i s requi red and m a ny

m o squi t o -control personnel at t e nd annual m eet i ngs of th e Northeast e rn M o squi t o C ontrol Associ at i on for such
tr ai ni ng. Speci fi cs for cert i f i cat i on and other appl i cat or i ssues are covered i n C M R333: Pest i c i d e B o ard. Mo st o f th e p e sticid es u s ed are ex trem ely safe, so h a n d lin g in stru ctio n s are m i n i m a l. Fo r Bti, m i n e ral o il or Golden Bear oil, and m e theprene products, work areas should be ventila ted and eye protecti on and im pervious gl oves worn. W i th th ese m a t e ri al s appl i cat ors shoul d al so wash thoroughl y aft e r handi ng or appl y i ng th em . W i th

m a l a th i on, perm ethri n and resm ethri n product s safet y goggl es, chem i cal resi st ant gl oves and a respi r at or shoul d be worn when formul at i ng spray m a t e ri al . Ey es shoul d be fl ushed i m m e di at el y and ski n washed wi th soap as qui ckl y as possible if accidental contact occu rs. Vom iting should not be induced fo r resm ethrin and perm ethrin products but shoul d be i nduced for m a l a th i on. In al l cases where resm ethri n , perm ethri n or m a l a th i on i s i ngest ed, a phy si ci an shoul d be cont act ed i m m e di at el y .2

. Larv icid es

a. B i ol ogi cal s: B t i and B. sphaeri cus i. Ba cillu s th u r in g i en sis var . israelensis M ode of Act i on. Ba cillu s th u r in g i en sis (Bt) is a n a tu rally o ccu rrin g , g r am p o s itiv e, ro d

- sh ap ed , sp o r e-fo rm in g bact eri u m , whi c h i s pathogeni c t o th e l a rvae of a num ber of i n sect s speci es, especi al l y Lepi dopt era, when i ngest ed by th e l a rvae. B t i i s al so a pathogen t o th e l a rvae of som e i n sect s i n th e order Di pt era (e.g., m o squi t o es and

m i dges). Ba cillu s th u r in g i en sis var. israelensis Serot y pe H14 (B t i ) i s a bi ol ogi cal i n sect i c i d e produced duri ng spory l at i on of th i s bact eri u m . The prot ei n product of th e H14 serot y pe (e.g., B act i m os, Vect obac and Teknar) i s used t o sel ect i v el y control th e l a rvae of m o squi t o and bl ackfl i e s. It i s a st om ach poi son whi c h al t e rs gut perm eability to salts under alkaline conditions. This decr eases feeding and developm ent and eventually causes death by st arvat i on (Hart l e y & Ki dd 1983). Fate in th e En v i ro n m en t. Th e resid u a l p e rio d fo r Bti h a s b een estim ated at 4 8 h rin water, as it g r ad u a lly settles o u t or adheres t o suspended organi c m a t t e r (SC A M P 1987). As a natu ral part of th e ecosy st em , B t i degrades t o

com p lex but non-toxic organic co m pounds which are ultim ately m i neralized (Hartley & Kidd 1983). Effect s on Non-t a rget organi sm s. There i s no evi d ence of acut e or chroni c t oxi ci t y of th e sp o r e-crystal co m p lex to

am phibians (tree frog tadpoles, toad tadpol es, California newt), fish (m osquito fish, rainwater kill fish, two-spine
st i c kl eback) or bi rds. It i s non-t oxi c t o bees. Groups of organi sm s th at have been reduced by B t i appl i cat i ons are from the suborder Nem a tocera of the order Diptera which includes species of the families Dixidae, Chironom idae, and C e rat opogoni dae (Fi s her & R o sner 1959, Garci aet al . 1980, Hart l e y & Ki dd 1983, W o rthi ng & W a l k er 1983). A recently com p leted study in Minnesota found B ti reduced chironom ids, tipulids, ceratopogonids and stratio my id s. Th ere is reaso n to b e liev e th is m a y h a v e negat i v e i m pact s on nest i ng ducks and th ei r duckl i ngs, for whi c h chi r onom i d s m a ke up a si gni fi cant part of th ei r di et (SPR P 1996). W h en a sm all stream was treated at 0.5 ppm /15 m i n. (13 ° C ) wi th an aqueous suspensi on of unformu l a t e d B e l l on pri m ary powder of B t i , i n contrast t o th e sharp reduct i on (89%) i n bl ack fl y l a rvae i n th e 20-350 m area bel o w th e tr eat m e nt poi nt , Surber sam p l e s i ndi cat ed i n creases i n m a y f l y (35%), caddi sfl y (47%), st onefl y (75%), chi r onom i d (19%), and el m i d (242%) popul at i ons. No adve rse effect on any of th ese non-t a rget popul at i ons was evi d ent fol l o wi ng stream tr eat m e nt (M ol l o y & Jam nback 1981). In l aborat ory and fi el d studi es conduct e d wi th B t i
t o det e rm i n e i t s effect upon Ae taeniorhynchus and non-target organism s in a salt m a rsh, Bti killed over 99% of them o squi t o l a rvae at concentr at i on of 4.5 IU/m l and above. Out of 39 speci es col l ect ed pri o r t o tr eat m e nt , onl y a hom i p t e ran (true bugs), N o t onect a i ndi ca , showed a si gni fi cant decrease i n popul at i on. However, th i s genus i s known t o fl y from det e ri orat i ng habi t a t s (Purcel l 1981). E xperi m e nt al t e st i ng has dem onstr at ed no adverse effect agai nst other aquat i c i n sect s i n cl udi ng dragonfl i e s, dam s el f l i e s, m a y f l i e s, st onefl i e s, caddi sfl i e s, wat e r beet l e s or true bugs. Other invertebrates such as Daphnia, cyclops, rotifers and crustaceans are also unaffected (SCAMP 1987). M a ny acut e t oxi ci t y / p athogeni ci t y studi es wi th vari ous vari et i e s of B t have b een conduct e d usi ng several
rout es of adm i ni strat i on i n rat s , rabbi t s , and gui nea pi gs. Am ong th e vari ous studi es revi ewed, th e hi ghest dose
t e st ed was 6.7 x 10 1l spores per anim al. There were no significant a dverse effects associated with these studies (Castillo 1986). No acute toxicity was obs erved in rats gavaged with the m a ximu m dosage of 2 billion spores of Bti H-14. No erythem aor edem a form ation were observed after derm al exposure to 1.6 billion spores. All other p a ram e ters o f th e test an im als were n o r m a l. Th ere was n o ev id en ce th at Bti H-1 4 mu ltip lied o n th e ab rad e d epiderm i s. No adverse effects were observed in rats gi ven 80 m illion viable spores by instillation into the lungs. There was no histological evidence of mu ltiplication of the organism in lung tissue. Instillation of 10 m illion Bti spores into the ocular cavity produced no eye irritation beyond 48 hr. No mu ltiplication occurred in the ocular cavity (Castillo 1986). Acute, or al and derm al toxicity (LD 50 ) of B t i H-14 (Vect obac) i s i n excess of 30,000 m g / kg. No al l e rgeni c response t o B. t huri ngi ensi s was el i c i t e d i n gui nea pi gs by i n tr ocut aneous i n ject i on, i nhal a t i on, or t opi cal appl i cat i on t o th e i n t act or abraded ski n (Hay es 1982). Each of 18 persons i ngest ed 1 g of a com m e rci a l B. t huri ngi ensi s preparat i on cont ai ni ng approxi m a t e l y 3 x 10 9 spores dai l y for 5 day s on al t e rnat e day s . In addi t i on t o i ngest i on, fi ve of th em i nhal e d 100 m g of th e powder d a ily fo r 5 d a ys. Th ere were n o co m p lain ts an d n o p o s itiv e fin d i n g s b y p h y sical an d lab o r ato r y ex am in atio n (Fish e r & R o sner 1959). W h en B t was appl i e d by ai rcraft at

a rat e of 2 kg of preparat i on (3 x 10 9 organi sm s/ g) per hect are (6 x 10 12 organism s/hectare) the concentra tion of viable organism s in the ai r over the field exceeded background by 42.5 tim es on the day of application and by 22.5 tim es 5 days later (Castillo 1986). No com p laints were received from ei ght m e n exposed for 7 m onths t o ferm ent a t i on broth m o i s t bact eri a l cake, effl uent , and th e fi nal powder i n th e course of com m e rci a l m a nufact ure of t h e pest i c i d e (Fi s her & R o sner 1959, Hay e s 1982).A dose of 10 7 (i.e., 1 0 m illio n ) Bti o r g a n i sm s k illed th e test an im als wh en in j ected in tro cereb rally (IC). Death was probabl y due t o th e m a ssi ve i

. c. i nocul um and not any i n fect i v e process. M o st of th e ani m al s di ed wi th i n 24 hours (Castillo 1986). The EPA' s revi ew of th e t oxi col ogi cal dat aon B t i det e rm i n ed th at no dat agaps exi s t i n th e t oxi col ogy dat abase and no m a jor envi ronm ent a l m a m m a l i a n safet y concerns (except for certain endangered species of Lepidoptera) were identified (Castillo 1986) . Toxicological data specially re quired for biochem i cal and m i crobial pesticide registration including: im munotoxicology studies, infecticity studies, intracer ebral test, tissue culture tests and vi rul e nce enhancem ent studi es (EPA 1984, M a rqui s 1986). B t i i s effect i v e onl y agai nst di pt eran l a rval (m osqui t o es and bl ack fl i e s) and i s safe t o th e envi ronm ent (W orth i ng & W a l k er 1983). B t i i s non-phy t o t oxi c and has shown no effect s on seed germ i n at i on or pl ant vi gor (SC A M P 1987). ii. Bacillus sphaericus M ode of Act i on. . Bacillus sphaericus i s a natu ral l y occurri ng bact eri u m , whi c h i s pathogeni c t o th e l a rvae of m a ny genera of m o squi t o es. There are a num ber of strai n s of B. sphaeri cus , th at b e in g m o st to x i c to m o sq u ito es is B. sphaeri cus 2363. Li ke B t i , i t produces a t oxi n th at mu st be i ngest ed and part i a l l y di gest ed before i t becom e s activated. Aedes m o sq u ito es are g e n e rally less su scep tib le to B. sphaeri cus. It is currently m a rketed as a granular larvicide by Abbot Labs under the trade nam e VectoLex CG and is of interest because it works better than Bti in hi ghl y organi c wat e rs oft e n favored by Culex speci es (Abbot t Laborat ori e s 1996). Al so of i n t e rest i s th e fact th at i t i s not t oxi c t o other di pt erans, i n cl udi ng bl ackfl i e s. It s l i m i t e d range of t oxi ci t y , whi l e a bl essi ng i n som e respect s, has sl owed devel opm ent as th e m a rket for B. sphaeri cus i s l i k el y t o rem a i n sm al l (Federi c i 1985). Fate in th e En v i ro n m en t. Bacillus sphaericus h a s a field life o f b e tween two an d fo u rweek s. Th e sp o r es settle o u t of the water colum n in as little as two days though they settle m o re slowly than Bti, as th ey adhere less to suspended part i c ul at es. The spores can rem a i n vi abl e for m onths i n th e fi el d (Youst e n et al . 1992). Bacillus sphaericus ma y undergo l i m i t e d recy cl i ng (reproduci ng i t s el f wi th i n th e l a rval gut of Cu lex species), especially in rich organic envi ronm ent s (Abbot t Laborat ori e s 1996, Karch et al . 1990). Bacillus sphaericus is ingested by other filter-feeding arthropods ( Daphni a pul ex and Cyp r is sp.) It can germ i n at e wi th i n th e gut of th ese ani m al s and m a y be spread by th em th rough th e envi ronm ent
. It does not seem t o adversely affect them and they m a y play a role in recycling B. sphaeri cus, th ereby i n creasi ng th e l e ngth of control achi e ved from a si ngl e appl i cat i on. Bacillus sphaericus does not affect popul at i ons of th e predat or speci es C l eondi pt eri u m, Co ri xa punct a t

and N e pa ci nerea. (Karch et al . 1990). Bacillus sphaericus can be used i n conjunct i on wi th th e fungus Lageni di um gi gat eum (Orduz and Axt e l l 1991). Effect s on non-t a rget organi sm s. Bacillus sphaericus, technical m a terial , had acut e oral and derm al LD 50 val u es for rat s of >5g/ kg and >2g/ kg respect i v el y , m a ki ng i t a cl ass IV larvicide. The technical m a terial can b e m o d e rately i rri t a t i ng t o th e ski n and ey es of peopl e. Toxicity tests on m a llards, bluegills , and rainbow trout showed the m a teri al to be extrem ely save to these ani m al s. Acut e t oxi ci t y t e st s on freshwat e r i nvert ebra t e s (daphni a and m a y f l y l a rvae) and sal t m a rsh and bay speci es (sheephead m i nnow, shri m p and oy st ers) al l i ndi cat e th at th e m a t e ri al i s essent i a l l y non-t oxi c. Honey bees are not affected by B. sphaeri cus (Abbot t Laborat ori e s 1996). Bacillus sphaericus i s not phy t o t oxi c (Abbot t Laborat ori e s 1996). b. M e thoprene M ode of Act i on. M e thoprene i s an i n sect growth regul at or (i .e., a sy nthet i c anal og of th e juveni l e horm one) whi c h does not allow insects to m a ture from the larval stages into reproduc tively capable adults. It shows little or no effect
on th e adul t or pupal st ages of i n sect devel opm ent
. Un l i k e ordi nary i n sect i c i d es, t h i s rel a t i v el y non-persi s t e nt chem ical exhibits m o rphological rather than direct toxic activities. Alt hough its exact m ode of action is not

com p letely known, three m odes have been investigated: 1) m e thoprene binds JH receptors resulting in extended juvenile form s which are not reproductively com p etent, 2) m e thoprene com p etitively inhi bits catabolic m e tabolism of JH which extends juvenile form s etc., and 3) m e thopren e binds to its own receptors and extends juvenile form s (M at sumu ra 1985). Fat e i n th e Envi ronm ent
. M e thoprene i s rel a t i v el y st abl e but nonpersi s t e nt i n th e envi ronm ent (SC A M P 1987). It does not bi ol ogi cal l y m a gni fy . In soi l , m e thoprene rapi dl y degrades wi th a hal f-l i f e of approxi m a t e l y 10 day s . In pl ant s i t s degradat i on pri n ci pal l y i nvol ves est e r hy drol y s i s , Odem ethy l a t i on, and oxi dat i v e cl earage of th e doubl e bond of the C4-position. In lucerne and rice, the principl e m e tabolite is 7-m e thoxycitronellal. Methoprene is very susceptible to photolytic decom positi on under environm ental conditions. It is degraded to m a ny photoproducts which are present in relatively low yield (<10%). Th e rapid degradation of m e thoprene and mu ltiplicity of photolytic products are indicative of ex tensive photodegradability in the natural environm ent (Quistad et al. 1975). Techni cal grade m e thoprene i s st abl e >4 y r . i n gl ass i n th e dark at 43 ° (W orth i ng & W a l k er 1983). St eri l e aqueous 0.5 ppm sol u t i ons at 98% pure [C 5 - 14 C ] m e thoprene, buffered at vari ous pH val u es, were found t o beextrem ely stable to hydrolysis over 4 weeks at 20 ° C in th e d a rk . No d e g r ad atio n (d etectab le lim it 1 % ) was seen in
st eri l e wat e r at pH 5.7 m e thoprene was rapi dl y phot oi som e ri zed (t 1/ 2-30 m i n.) t o a fi nal 2E: 2 % i s om eri c m i xture of 44: 56. The 2% i s om er of m e thoprene has a mu ch l o wer bi ol ogi cal act i v i t y th an 2E-m ethoprene i t s el f, hence phot oi som e ri zat i on of m e thoprene i n th e fi el d shoul d qui ckl y resul t i n a nondegradat i v e l o ss of about hal f th e biological activity. Solutions of m e thoprene (0.5 ppm ) were found to under go photoinitiated decom position to m o re pol ar product s , t o th e ext e nt of 15% i n 2 day s and 332 i n 3 day s at 20 ° C

. Earl i e r experi m e nt s at 0.1 ppm at

t w o t e m p eratures (24 and 40 ° C ) had shown no breakdown at 24 ° C and onl y 5% breakdown at 40 ° C , i n 1 day (School ey et

al . 1975). In pond wat e r, th e hal f-l i f e of m e thoprene i s approxi m a t e l y 30 hr at 0.001 ppm and 40 hr at 0.01 ppm

. Incubation of (2E)-[C 10 - 14 C] m e thoprene for 3 days at 0.42 ppm genera ted three prim ary m e ta bolites, the result of ester hydrolysis and/or O-dem e thyl ation. These m e tabolites and recove red m e thoprene were photoequilibrium

m i xtures of 2-ene doubl e bond i s om ers (e.g., E and %). In another i n cubat i on experi m e nt wi th (2E)-[C 5 - 14 C]

m e thoprene at 0.66 ppm i n a pond wat e r sam p l e of presum abl y di fferent m i crofl o ra, a com p l e t e l y di fferent

m e tabolite was identified as resulting from oxidative scissi on of the 4-ene double bond. The principle m e tabolite in the latter experim e nt was 7-m e thoxycitronellic acid. M e thoprene was rapi dl y degraded when a th i n fi l m (0 .1 u) on gl ass was exposed t o sunl i ght th rough gl ass. The half-life under these conditions was 6 hr. After expos ure to sunlight for 27 hr, only 3% of the applied dose

rem a i n ed as m e thoprene and i t was i s om eri zed t o a 50: 50 m i xture of (2E,4E) and (2%,4E)-m ethoprene. The recovery of only 72% of the applied radioactivity after 27 hr suggested photolysis of m e thoprene to volatile product s whi c h were l o st by vapori zat i on. C o l l ect i on of vapors above th e phot ol y s at e resul t e d i n recovery of 13% of the applied radioactivity. The vol atile constituents were resolved in to m e thoxycitronellal (4%), m e thoprene (0.2%) and 14 C0 2 (6%). Since only a trace am ount of m e thoprene (0 .2%) was detected in the condensed vapors, volatility of m e thoprene is not considered a m a jor route for loss of radioactivity. Effect s on Non-t a rget Organi sm s. M e thoprene i s non-t oxi c t o bees, and rel a t i v el y non-t oxi c t o non-t a rget speci es but shrim p and crabs m a y be killed (Hartley & Kidd 1983, SCAMP 1987). Methoprene does have som e toxicity to
th e sal t m arsh copepod Apocyclops spartinus , but th e concentr at i on of m e thoprene i n th e wat e r requi red t o cause tr ansi ent reduct i ons i n th e earl y l i f e st ages of th e copepod i s above th at whi c h shoul d occur duri ng rout i n e m o squi t o control (B i r cher & R uber 1988). M e thoprene di d not adversel y affect th e copopods Cyclops vernalis and Cyclopsnavus i n a M i nnesot astudy but di d reduce chi r onom i d s, t i pul i d s, cerat opogoni ds and strat i o my i d s (SPR P 1996). As for B t i appl i cat i ons, reduci ng chi r onom i d popul at i ons m a y have a l ong-t e rm effect on nest i ng ducks. The acute toxicity (96hr-LC 50 ) of m e thoprene t o a vari et y of fi sh ranged from 1.6 ppm for rai nbow tr out t o great er th an 100 ppm for channel cat fi sh (Johnson & Fi nl ey 1980). In a m odel ecosystem study on th e uptake and degradation of m e thopr ene by bluegills, the fish had a surpri si ngl y l a rge am ount of radi oact i v i t y aft e r 4 t o 6 weeks of exposure. If th e radi oact i v i t y was due t o th e presence of parent m e thoprene, one would have concluded that the com pound was bioaccumu lated several thousand
t i m es. However, l e ss th an 0.l % of th e m easured radi oact i v i t y was i n th e form of m e thoprene and i t s pri m ary

m e tabolites, with the rest being presen t in such natural products like choles terol, proteins, free fatty acids, and glycerides. W ith this correction factor , m e thoprene was bioconcentrat ed by bluegills to a m oderate extent. In clean water, bluegills elim inated 93 to 95% of the accumu la ted body burden of m e thoprene in less than 2 weeks. Two formul at i ons of m e thoprene were appl i e d aeri a l l y (0.1 l b a.i

. / acre) t o ri ce fi el ds i n th e Sacram ent o Val l e y of C a l i f orni a. The l e vel of control of Cx. ta rsa lis was assessed in em ergence cages established before and aft e r spray i ng i n th ese and control fi el ds. Aft e r spray i ng, th e tr eat ed fi el ds had about one hal f th e rat e of Cx.
ta rsa lis em ergence as di d control fi el ds. None of th e non-t a rget organi sm s exam i n ed exhi bi t e d popul at i on fl uctu at i ons whi c h coul d be st at i s t i cal l y at tr i but ed t o th e m e thoprene appl i cat i ons (C ase & W a shi no 1978). Lo co m o to r activ ities o f m o sq u ito fish ( Ga mb u s ia a ffin is ) and gol dfi s h ( Carassus auratus ) were

m oni t o red for a 2-week peri od i n th e presence of m e thopren e at concentr at i ons approxi m a t e l y 10-fol d great er th an those general l y recom m e nded for appl i cat i on. M e thoprene, th e act i v e i ngredi e nt i n Al t o si d SR -10, at 0.2 ppm di d
not si gni fi cant l y al t e r th e l o com o t o r act i v i t y of ei th er m o squi t o fi sh or gol dfi s h (El l g aard et al . 1979). The acute oral toxicity (LD 50 ) of m e thoprene t o m a l l a rd ducks was assessed as great er th an 2000 ppm

. However, tr eat m e nt l e vel s as l o w as 520 ppm produced si gns of i n t oxi cat i on i n m a l l a rds (Sm i th 1987). The ei ght

day di et ary LC 50 for chi c kens was great er th an 4640 ppm (Hart l e y & Ki dd 1983). Thus, m e thoprene shows onl y sl i ght t oxi ci t y t o fi sh and bi rds and i s rel a t i v el y non-t oxi c t o non-t a rget speci es (SC A M P 1987). W h en th e m e t abol i c fat e of m e thoprene was studi ed i n a gui nea pi g, a st eer, and a cow, a rath er l a rge percentage of the radiolabel was incorporated in the tissues and respired by the anim als. In the urine and feces, a

sm all am ount of radiolabel was m e tabolized into free prim ary m e tabolites, som e what m o re was incorporated into sim p le glucuronides, and a consider able quantity of radiolabel was f ound in polar com pounds, possibly com p lexconjugat e s or pol ar bi ochem i cal s. No parent m e thopren e was found i n th e uri n e, but approxi m a t e l y 40% of th e radiolabel in feces was cont ributed by unm etabolized m e thoprene. The form ation of conjugates and the m e tabolism of m e thoprene was m o re ext e nsi v e i n th e st eer th an i n th e gui nea pi g (C ham b erl a i n et al . 1975). Sam p l e s of fat ,
mu scle, liver, lung, blood, and bile from a steer which received a single dose of [C 5 - 14 C ] m e thoprene were anal y zed for radioactive residues. No prim ary m e thoprene m e tabo lites could be characterized, but the m a jority (16-88%, d e p e n d i n g o n tissu e) o f th e to tal tissu e rad i o activ ity was p o s itiv ely id en tified as [ 14 C ] -chol est e rol

. Sevent y - t w o percent of th e bi l e radi oact i v i t y was contri but ed by chol es t e rol , chol i c aci d, and deoxy chol i c aci d. R a di oact i v i t y from cat abol i zed m e thoprene was al so associ at ed wi th prot ei n and chol est e ry l est e rs of fat t y aci ds (Qui st ad et al

. 1975). Acut e oral t oxi ci t y (LD 50 ) of m e thoprene i n rat s i s great er th an 34,000 m g / kg. That for dogs i s great er th an 5000-10,000 m g / kg. Derm al LD 50 val u es of m e thoprene are great er th an 3500 m g / kg for rabbi t s . It i s noni rri t a t i ng t o both th e ski n and ey es of rabbi t s (Hart l e y & Ki dd 1983, W o rthi ng & W a l k er 1983). M e thoprene has an i nhal a t i on LC 50 val u e of great er th an 210 m g / l i n rat (Si n e 1984). In 2-y rfeedi ng tr i a l s , no m e thoprene-rel a t e d effect s were observed i n rat s at 5000 m g / kg di et and i n m i ce at 250 m g / kg di et . No effect s were observed at th e hi ghest rat e s t e st ed: i n 3-generat i on reproduct i on studi es i n rat s (2500 m g / kg di et ); t e rat ogeni ci t y i n rabbi t s (500

m g /kg) or rats (1000 m g /kg); mu tageni city in rats (2000 m g /kg) (SCAMP 1987). Hollingsworth calculated the VSR for m e thoprene t o be great er th an 1,730,000. M e thoprene i s one of th e m o st sel ect i v e i n sect i c i d es present l y avai l abl e (W i l k i n son 1976). M e thoprene i s not phy t o t oxi c.

c. Oils Petr ol eum oi l s are al so known as m i neral oi l s and refi ne d grades have been cal l e d whi t e oi l

. Petr ol eum oi l s are p r ep ared b y th e d i stillatio n an d refin e m e n t o f cru d e m i n e ral o ils. Th o s e u s ed as p e sticid es g e n e rally d i still >310 ° C t o 335 ° C , nam e l y ; "l i ght " (67-79%), “m edi u m ” (40-49%), and “heavy ” (10-25%) (SC A M P 1987). They consi s t l a rgel y of al i phat i c hy drocarbons, both satu rat e d a nd unsaturat ed, th e cont ent of th e l a t t e r bei ng reduced by refinem e nt. Recently, highly re fined oils have been used as adjuvants to increase the effectiveness of som e other pest i c i d es (Hart l e y & Ki dd 1983). Petr ol eum oi l s m a y be used as di l u ent s for pest i c i d es or by th em sel v es Petroleum oils are also used alone as insecticides. Inhalation of o ils from the surface of water attacks

m o squi t o l a rvae th rough th ei r respi r at ory sy st em . Death occurs due t o reduced oxy gen l e vel s (hy poxi a) and l ack offeed in g . Petro l eu m o ils also en h a n ce p e n e tratio n o f th e in sect cu ticle b y th e in secticid e. In b i o a ssays o f in secticid al

com pounds, sel ect i v e t oxi ci t y has been not ed t o vary fo r th e sam e com pound dependi ng on th e natu re of th e carri er sol v ent and si t e of appl i cat i on. The degree t o whi c h a sol v ent i nduces rapi d penetr at i on th rough th e i n sect cut i c l e has been term ed its carrier efficiency. Thi s carri er effi ci ency can be di rect l y rel a t e d t o and i s dependent on th e p h y sical p r o p e rties o f th e so lv en t-in secticid e co m b in atio n . Di fferences in carrier efficiency have been at tr i but ed t o the ability of the solv ent to dissolve the outer la yer of the insect epicuticle (Schouest et al. 1983). Petroleum oils are used as su rface treatm e nts to prevent m o squito es from breathing at the surface. Petr ol eum oi l s have been shown t o be phy t o t oxi c t o pl ant s so use i n struct i ons shoul d be fol l o wed and oi l used onl y duri ng th e dorm a nt peri od (Hart l e y & Ki dd 1983). Petro l eu m o ils/Flit ML0 are m i n e ral o ils u s ed as d ilu en t/ad j u v a n t o ils o ras a p h y sical to x i can t wh ich k ills

m o sq u ito larv ae v i a su ffo catio n . Bo th are p r ep ared b y th e d i stillatio n an d refin e m e n t o f cru d e m i n e ral o ils. Th o s e

u s ed as p e sticid es g e n e rally d i still >3 1 0 ° C. They m a y be classified by the proportion distilling at 335 ° C, n a m e ly:

' l i ght ' (67-79%), ' m edi u m ' (40-49%), and ' h eavy ' (10-25%) (W orth i ng & W a l k er 1983). Acut e oral LD 50 for rats and m i ce >4300 m g ' A ct i p ron' / kg. No t oxi col ogi cal probl em due t o petr ol eum oi l s has been report e d i n pract i ce. Test s have shown t h ere i s no ri sk of pol y nucl ear arom at i c com pounds ent e ri ng th e food chai n usi ng m i neral oi l s for i n sect control (Hart l e y & Ki dd 1983). In 1968, th e M e di cal R e search C ounci l i n th e Uni t e d Ki ngdom publ i s hed i t s report , "The C a rci nogeni c Action of Mineral Oils," based on work done in several British universities. The m o st biologically active fractions (boi l i ng range of 300-400 ° C) were distilled further. The carcinogenic ac tivity appeared to occu r in m a terials which boi l e d above 350 ° C (presence in lower-boiling fractions was possi bly the result of azeotropism ), and activity was still p r esen t in fractio n s b o ilin g at 4 2 0 ° C

. Over 40 chem i cal com pounds were i s ol at ed from m i neral

- oi l fract i ons,

m a ny for th e fi rst t i m e, by repeat ed chrom a t ography , com p l e xi ng wi th pi cri c aci d and tr i n i tr obenzene, and fract i onal cry s t a l l i zat i on. Further studi es of th e natu re of th e act i v e com pounds di d not i d ent i f y any si ngl e hi ghl y pot ent carci nogen. Several of th e com pounds separat e d were structural l y si m i l a r t o very pot ent carci nogens, and th e t o t a l act i v i t y of th e oi l coul d be caused by th e com b i n ed effect of several i ndi vi dual l y weak carci nogens (Ki p l i ng & C ooke 1984).Al bi no rat s were dosed oral l y by st om ach tube at vary i ng rat e s up t o 10,000 m g FLIT M L O/ kg B W and

o b s erv e d fo r m o rtality an d sig n s o f sy stem ic to x i city fo r 1 4 d a ys. Th e LD 50 was never reached and it was concl uded th at th e LD 50 for FLIT M L O i s above 10,000 m g / kg B W . A dose of one pi nt of FLIT M L O adm i ni st ered
t o a horse by st om ach tube showed no gross react i ons. FLIT M L O was appl i e d t o th e exposed abdom i n al ski n of al bi no rabbi t s at dosage l e vel s up t o 3.16 g/ kg B W . Aft e r 24 hr, th e resi due was rem oved, and th e ani m al s were observed for a t o t a l of 14 day s aft e r appl i cat i on. There were no deaths or si gns of sy st em i c t oxi ci t y at any dosage l e vel t e st ed. There was no derm al i rri t a t i on t o unabraded ski n on any of th e ani m al s. A sl i ght t o m ode rat e redness appeared on abraded ski n . At th e end of th e 14-day peri od, th e ski n of al l ani m al s was com p l e t e l y cl ear of any si gns of i rri t a t i on. Al bi no rat s (10 m a l e and 10 fem a l e ) were exposed c ont i nual l y for 1 hr t o an at m o sphere cont ai ni ng an average of 200 m g FLIT MLO (aerosol) per liter (1) of air. Observations of m o rtality or signs of acute toxicity

were m a de at i n t e rval s th roughout th e exposure, and th e an i m al s were observed for 14 day s aft e r exposure. There were no deaths duri ng exposure or i n th e 14 day s th ereaft e r. Duri ng th e post

- exposure peri od th e respi r at i on rat e s

o f

th e an im als seem ed elev ated in itially, b u t retu rn ed to n o r m a l with in 2 4 h r . A slig h t lo ss o f fu r o ccu rred after a few day s , but th i s effect had di sappeared i n al l but four ani m al s by th e end of th e study . Other superficial effects (exudat e around th e ey es, et c.) were observed but qui ckl y di sappeared. FLIT MLO (0.1 m l ) was placed in the left eyes (the ri ght eyes served as a contro l) of nine albino rabbits. The ey es of th ree of th e rabbi t s were i rri gat e d aft e r t w o s econds; those of another th ree aft e r four seconds; th e ey es of th e rem a i n i ng th ree were l e ft uni rri gat e d. Peri odi c obs ervat i ons for si gns of ey e i rri t a t i on were m a de, wi th th e l a st observat i on m a de 7 day s aft e r appl i cat i on. There was no evi d ence of sy st em i c effect due t o any of th e ap p licatio n s . Eye irritatio n was slig h t an d tran sien t in all an im als. All sig n s o f th e e ffect had cleared within four day s fol l o wi ng appl i cat i on. Exam i n at i on on th e seventh da y confirm e d the absence of an y corneal dam a ge. R a t i ngs on th e Drai ze scal e, a com m on scori ng sy st em , were as fol l o ws: 4 at one and four hours, 2 at 24, 48, and 72 hours, and zero th ereaft e r (Exxon 1973). B oni de M o squi t o Larvi c i d e i s a l o w-order, l o w-vi scosi t y , hi ghl y satu rat e d petr ol eum hy drocarbon m i neral oi l th at ent e rs m o squi t o l a rval breathi ng tubes and spreads over m a i n tr acheal tr unks. These respi r at ory path way s t w i s t and col l a pse reduci ng oxy gen l e vel s t o t i ssues. Death i s by hy poxi a and l ack of feedi ng. It i s vi rtual l y id en tical to Flit MLO.The resi dual peri ods of petr ol eum oi l s are rel a t i v el y short

. Test s have shown th ere i s no ri sk of pol y nucl ear arom at i c com pounds ent e ri ng th e food chai n. No t oxi col ogi cal probl em s due t o th e use of petr ol eum oils for m o squito control have been reported in practice (W orthing & W a lker 1983). It has som e hazard to fish but little or no hazard to birds. Flit MLO has been evaluated to determ ine its effects on the aquatic environm ent. In a series of laboratory tests on grass shri m p , fiddler crabs, goldfish, bluegill, sunfish, fathead m i nnows, coho salm on, k illifish , an d d o m estic d u c k s , in wh ich field ap p licatio n s o f th e larv icid e were simu lated an d ex ag g e rated , Flit MLO was found t o have no adverse effect s even at concentr at i ons wel l above th e recom m e nded appl i cat i on rat e s of 1 t o 5 gal l ons per acre (Exxon 1973). Little or no hazard has been associat ed with the application of petroleu m oils to beneficial and non-target invertebrates. Other Dipter a that land on pools treated with oils will be pulled into the water due to the loss of surface tension and water beetles can often be obser ved crawling out of treated pools (Christie, personal observation). The flies clearly die, the beetles probably do not. Som e hazar d has been determ ined for honey bees. Isooctadecanol (Arosurf MSF), is a surface-acting ethoxylated fatty alcohol (i .e., a nonionic surfactant) which form s a thin film over the surface of water creating a physical barrier due to redu ced surface tension. This resul t s i n th e suffocat i on of aquat i c l a rvae and pupae (EPA 2/ 15/ 84). Fol i a r absorpt i on, tr ansl ocat i on i n pl ant s , and

m e t abol i s m and persi s t e nce i n pl ant s i s not avai l abl e (EPA 2/ 15/ 84). Dat aon m i crobi al breakdown shows th at Arosurf M SF i s degraded by unaccl i m at ed, m i xed cul tu res of m i croorgani sm s from natu ral sources by shake cul tu re

m e thods. Although not available for Ar osurf MSF, sim ilar ethoxylates degr ade under field conditions with the

m a jor rout e of degradat i on bei ng hy drol y s i s at th e ethe r l i nkage and subsequent oxi dat i on of th e al ky l chai n t o lo wer m o lecu lar p o l yeth ylen e g l yco l e-lik e m a terials wh ich are u ltim ately m i n e ralized to C0 2 and H 2 O. The resul t a nt average persi s t e nce for i s ooct a decanol has been det e rm i n ed t o be 2-10 day s (EPA 2/ 15/ 84). Al though in co m p lete, th e 9 6 h r- LC 50 for Daphnia is reported as 1.9 ppm . Bioaccu mu lation data is also lacking but studies on cl osel y rel a t e d fat t y aci d and fat t y al cohol ethoxy l a t e s i n shel l f i s h support th e cont ent i on th at th e com pound i s rap i d l y cleared fro m aq u a tic in v e rteb rates as in ert m e tab o lites. Arosurf M SF was used i n sm al l am ount s for several y ears i n th e l a t e 80’s and earl y 90’s and i s not current l y bei ng sol d . It i s i n cl uded here both for hi st ori cal purposes and i n th e off chance th at i t

m i ght becom e available again. As a surfactant, it form s a thin film over the surface of the wa ter. Its m ode of action is physical rather than chem ical in that it redu ces the water surface tension resulting in suffocation of the larvae and pupae.These nonionic surface-active film s spread into uniform , nearly m onom olecular layers, and can not be seen because th ey are to o th in to ab so rb lig h t o r cause iridescence due to reflective interfe rence. Peri odi c observat i ons i ndi cat ed that wind velocity as low as 2-3 m ph can push the film ove r the water surface to the downwind side or corner of a pond wi th i n m i nut es aft e r tr eat m e nt , th ereby est abl i s hi ng areas of hi ghl y com p ressed fi l m and areas of essent i a l l y no fi l m (Levy et al . 1980). Average persi s t e nce for Arosurf M SF has been det e rm i n ed t o be 2 t o 10 day s at

recom m e nded dosage rates (Miller 1984). Monom olecular film s are biodegrad able and have shown no adverse effect s on m a m m a l s and several speci es of vert ebrat e and i nvert ebrat e aquat i c organi sm s so th ese m a t e ri al s shoul d not pose a threat to the environm ent or a health hazard to m a n. An exem pt i on from th e requi rem e nt of a t o l e rance for th e pest i c i d e i n or on fi sh, shel l f i s h, i rri gat e d crops,

m eat , m i l k , poul tr y and eggs, when used as a m o squi t o c ontrol agent i n aquat i c areas has been est abl i s hed under 40 C F R18Q.1078. Studi es on cl osel y rel a t e d fat t y aci d a nd fat t y al cohol ethoxy l a t e s havi ng vari ous degrees of
ethoxy l a t i on support e d th e cl earance of th e chem i cal as an i n ert i ngredi e nt and were al so used i n support of th e

exem pt i on as an act i v e i ngredi e nt (EPA 1984). Arosurf M SF dem onstr at es l o w m a m m a l i a n t oxi ci t y (cat egory III). Isooct a decanol has dem onstr at ed l o w t oxi ci t y t o fi sh, bi rds and other wi l d l i f e and non-t a rget organi sm s. Acut e t oxi ci t y (96hr-LC 50 ) of isooctadecanol to fish range from 98 ppm (rainbow trout) to 290 ppm for bluegill (Miller 1984). Qualitative data on non-target anim als and plants expos ed to various dosages of Arosurf MSF during field trials to co n tro l m o sq u ito es h a v e in d i cated th at th is film will cau se little o rn o ad v e rse effects to th e en v i ro n m en t. Som e m o rtality of pupae and/or em erging adults of certa in m i dge species (Chironom id ae) breeding in aeration and decom position ponds at sewage treatm e nt system s was noted. However, signi ficant m o rtality of m i dges was also observed in som e control (untreated) se wage ponds containing a similar layer of natural surface scum s. Therefore,
th e tr ue i m pact of Arosurf M SF on th e reduct i on of th e m i dge popul at i on i s not known. Adul t dragonfl i e s were observed t o ovi posi t i n wat e r tr eat ed wi th Arosurf M SF and a Gambusia sp. was observed eat i ng l a rge l e nses of fl oat i ng Arosurf M SF wi th no apparent adverse affect s. Fi el d and l aborat ory t e st s i ndi cat ed th at predat i on and asexual reproduct i on of th e m o squi t o pl anari a n Dugesi a dorot ocephal a (W oodworth ) and th e i n fect i v i t y and devel opm ent of th e m o squi t o nem a t ode Romanomermi s cul i c i v ora (R oss and Sm i th ) were not adversel y affect ed by Arosurf MSF at surface dosages of 0.4-0.5 m l/m 2 . Although no quantitative data we re obtained concerning theeffect s of Arosurf M SF on th e natu ral popul at i ons of ani m al s and pl ant s , general observat i ons i ndi cat ed th at th ere appeared t o be few l ong-t e rm effect s (W ard 1966). Arosurf M SF was effect i v e i n reduci ng 3rd and 4th i n st ars of Ae. ni gromacul i s and Ae. melanimon populations at 0.5 and 1.0 m l/m 2 surface rates, averagi ng 88% and 96% m o rtality reduc tion, respectively. Nont a rget arth ropods whi c h showed acut e l e th al effect s were cori xi ds ( Corisella spp.). Not onect i d s ( N o t onect a

u n ifa scfa ta ), clam shrim p ( Eul i m nadi a sp.), and Tro p i stern u s la tera lls beet l e adul t s . Non-t a rget s th at di d not

ex h i b it m o rtality were m a yfly ( Ca llib a e tis spp.) nai a ds, chi r onom i d l a rvae and copepods (Takahashi et al . 1984). Under fi el d condi t i ons, th i s fi l m -form i ng subst a nce pr oduced a hi gh l e vel of control (90%+) of l a rvae and pupae of Cx. ta rsa lis at th e rat e of 0.5 t o 0.75 gal / acre wi th no apparent effect on non-t a rget organi sm s such as

m a y f l y nai a ds, di vi ng beet l e adul t s , ostr acods and copepods (M ul l aet al . 1983). d. Others Tem e phos (Abat e ) i s a non-sy st em i c i n sect i c i d e used as a rel a t i v el y sel ect i v e l a rvi c i d e agai nst m o squi t o es,

m i dges, gnat s , punki es sand fl i e s, th ri ps and bl ack fl i e s (S C A M P 1987). It has not been used i n M a ssachuset t s for several y ears. It i s non-phy t o t oxi c when used as reco m m e nded but i s not general l y used on pl ant s (Hart l e y & Ki dd 1983. SC AM P 1987). It has rel a t i v e l ong resi dual act i on but short resi dual t i m e i n soi l s and wat e r (SC A M P 1987). In pl ant s , t e m e phos i s oxi di zed t o th e sul f oxi de and, t o a l e sser ext e nt , t o th e sul f one and m ono- and di

orthophosphates. Further degr adation proceeds very slowly (Hartley & Kidd 1983). In insects, the thiophosphate group and sul f ur at om i n th e sul f i d e group of t e m e phos undergoes a st ep wi se oxi dat i on. The oxi dat i v e com pound is then hydrolyzed, and the final m e tabolite is 4,4' -dih ydroxy diphenyl sulfone (Aizaw a 1982). These reactions are hi ghl y speci es dependent whi c h provi des t e m e phos' s sel ect i v e act i on. Tem e phos has som e hazard to non-targ et and beneficial insect but is highly toxic to hone ybees by direct contact (topical LD 50 is 1.55 ug/bee). It is also hazardous to crus taceans such as shrim p and crabs (SCAMP 1987). At

100-1000 ppb, t e m e phos causes som e reduct i on i n ° 2 eval uat i on by al gae (Verschueren 1983). The 96 hr - LC 50 for tem e phos to crustaceans range from 45-82 ppb and the m e dian threshold lim it (TLm ) for shrim p range from 249 ppb 2550 ppb. The LC 50 val u es of t e m e phos t o non-t a rget aquat i c i n sect s range from 1-2 ppb (Ephem e ropt era) t o 500-1000 ppb (Tri copt era) (1 hr-LC 90-95 ). The 96hr-LC 50 val u e for st onefl i e s i s 10 ppb (Verschueren 1983). Tem e phos (Abat e 4E) di d reduce popul at i ons of copepods and cl adocerans i n a t e st i n m a n-m a de ponds but th e popul at i ons recovered wi th i n several weeks. Ostr acods were not affect ed (Fort i n et al 1987).Tem e phos i s st abl e when st ored at room t e m p erature, m oderat e l y st abl e t o hy drol y s i s i n cont act wi th aq u e o u s alk a li, b u t th e rate o f h y d r o l ysis in creases with p H . Op timu m stab ility is at p H 5

- 7 with in creased hy drol y s i s occurri ng at 2>pH>9 at rat e s dependi ng on t e m p erature. Tem e phos m a y be oxi di zed t o th e sul f oxi de, th e sul f one, and th e m ono- and di oxy gen anal ogs. The sul f oxi des and sul f ones of th e oxy gen anal ogs have not been observed. Hy drol y s i s product s i n cl ude th e th i ophenol and th e correspondi ng sul f oxi de and sul f one (R eed 1982). In a study usi ng 3H-l abel ed t e m e phos t opi cal l y appl i e d t o bean pl ant s , unchanged t e m e phos com p ri sed

m o re th an 70% of th e t e rm i n al resi dues aft e r 28 day s . The sul f oxi de com p ri sed about 4% of th e resi dues. The other oxidative m e tabolites were present in very sm all am ounts. Conjugates of the hydrolys is products com p rised the

rem a in in g resid u e s. Mo re th an 9 0 % o f th e ap p lied activ ity rem a i n ed aft e r 28 day s , i ndi cat i ng th at resi due decl i n e i s pri m ari l y th e resul t of growth di l u t i on (R eed 1982). In l aborat ory studi es, t e m e phos has a hal f-l i f e of 108 day s i n aqueous m e di a. However, t e m e phos degrades

m o re rapi dl y i n sam p l e s of reservoi r, pol l u t e d brook, and puddl e wat e rs wi th hal f-l i v es rangi ng from 9-32 day s . Tem ophos rapi dl y phot odegrades t o th e sul f oxi de and th en t o other oxi dat i v e and hy drol y t i c product s . Sanders et al ., (1981) report e d concentr at i ons rangi ng from 0.15 ug / l t o 10 ug/ l i n sm al l freshwat e r ponds 24 hr aft e r appl i cat i on. Henry et al . (1971) m easured t e m e phos concen tr at i ons aft e r si mu l a t i ng sal t m arsh appl i cat i on rat e s (26 t o 131 ug/ l ) and report e d di sappearance rat e s as a funct i on of t e m p erature. Tem e phos concentr at i ons rangi ng from 16 ug/ l t o 34 ug/ l were found i n st agnant ponds aft e r appl i cat i on by hel i c opt er, wi th a hal f-l i f e of approxi m a t e l y 5 hr (Lores et al . 1985). Peak concentr at i on of t e m e phos i n wat e r duri ng earl y M a y occurred wi th i n 1 hr of tr eat m e nt of a 4 EC formul at i on (m ean approx. 20 ug/ l ) and wi th i n 8 hr of tr eat m e nt wi th th e 2G formul at i on (m ean approx. 9 ugtl). The rate of degradation in wate r appeared to be affected by the initia l solubility of tem e phos which is itself i n fl uenced by th e appl i cat i on si t e , th e wat e r t e m p erature and th e formul at i on appl i e d. These fi ndi ngs support a general half-life disappearance of 24 hr for the ac tive ingredient under conditi ons found in local spring Aedes breedi ng habi t a t (M ackenzi e et al . 1983). Little d a ta ex ists fo r so il d e g r ad atio n , b u t th ere are in d i catio n s th at certain so il b acteria are cap ab le o f causi ng rapi d degradat i on of t e m e phos t o wat e r-sol ubl e hy dr ol y s i s product s . The m ean peak concentr at i ons of
t e m e phos resi dues i n sedi m e nt s were i n th e 250-500 ug/ kg range fol l o wi ng a si ngl e earl y spri ng appl i cat i on of 90- 100 g/ ha and decl i n ed t o negl i g i b l e l e vel s i n 10 day s (M ackenzi e et al . 1983).From an anim al m e tabolism study, data from ca ttle indicate that tem e phos and its sulfoxide are i n t e rconvert i b l e i n ani m al s. The sul f oxi de was present i n th e m i l k of cows fed 20 ppm t e m e phos and t e m e phos was present in the m ilk of cows fed 5 ppm of the sulfoxide (EPA 1986). All of the oxidative m e tabolite of tem e phos are expect ed C h E i nhi bi t o rs, but t e rm i n al resi dues appear t o consi s t pri m ari l y of t e m e phos and i t s sul f oxi de (EPA 1981). W h en 3H-tem ephos was orally adm i nistered to rats, radioactivity reach ed a peak in the blood between 5 and 8 hrs and th en di ssi pat e d wi th a hal f-l i f e of about 10 hrs. Appreci abl e radi oact i v i t y was found onl y i n th e gastrointestinal tract and fat. Both in feces and in fat, m o st of the ac tivity cam e from unchanged insecticide, but

sm all am ounts of the sulfoxide were present also. W h ile traces of tem e phos were found in the urine, the principal

u r in ary m e tab o lites were su lfate ester co n j u g a tes o f 4 , 4 ' -th i o d i p h e n o l , 4 , 4 ' -su l fin y l-d i p h e n o l , an d 4 , 4 '

- sul f ony l d i phenol . At l east 10 other com ponent s coul d be extr act ed but were not i d ent i f i e d. In th e gui nea pi g, absorption apparently was less than in the rat, and biliary excretion of m e tabolites was dem onstrated (Hayes 1982). Tem e phos was derm ally applied to cattle as a 0.l% sp ray and the cattle were slaughtered 7, 14, 28, 42, and 56 day s aft e r tr eat m e nt . Tem e phos was not det ect ed (<0.05 ppm ) i n any sam p l e of mu scl e or l i v er, but was det ect ed i n th e ki dney at 0.08 and 0.13 ppm i n 2 of th e 3 ani m al s sl aught ered aft e r 7 day s . Tem e phos averaged 1.19 ppm i n the fat of the 3 anim als killed at 7 days and declined thereafter with a half- life of 6 days. Tem e phos sulfoxide was d e tected at lev e ls o f 0

. 3 9 an d 0

. 0 9 p p m o n l y in th e fat o f cattle k illed 7 an d 1 4 d a ys, resp ectiv ely, after treatm e n t . In a study where 14 C

- l abel e d t e m e phos was spray e d on l act at i ng goat s , resi dues i n th e back fat were predom i n ant l y t e m e phos. R e si dues i n om ent a l fat and m i l k were predom i n ant l y th e sul f oxi de wi th som e sul f one and, i n l i v er, residues of the sulfoxide and the sulf one were roughly equal. Other oxidative and hydr olytic m e tabolites were present i n onl y sm al l am ount s. Therefore, m e t abol i s m and el i m i n at i on of t e m e phos i s rapi d wi th about 95% of a single oral dose elim inated in the ur ine and feces within 96 hours (EPA 1981). The acute oral toxicity (LD 50 ) of t e m e phos i n rat s i s 770-13,000 m g / kg t 8600 m g / kg), and 4000 m g / kg for

m ouse. Tem e phos has an acut e derm al t oxi ci t y (LD 50 ) for rabbi t of 1300-1930 m g / kg and great er th an 4000 m g / kg for rat s (Hart l e y & Ki dd 1983, W o rthi ng & W a l k er 1983). Tem e phos and m a l a th i on showed an approxi m a t e l y fourfol d pot ent i a t i on i n rat s when th ey are gi ven t ogeth er at l e vel s approachi ng th ei r LD 50 values (Gaines et al. 1967). However, under other conditi ons no potentiation was observed betw een tem e phos and 23 other organic phosphorus com pounds (Levi n skas & Shaffer 1970). Tem e phos has a TW ATLV val u e of 10 m g /m 3. The
th reshol d l i m i t val u e of 10 m g /m 3 i ndi cat es th at occupat i onal i n t a ke at a rat e of 1.4 m g / kg/ day i s consi d ered safe.In a neurot oxi ci t y study , hens were fed 230, 460, and 920 ppm t e m e phos for 30 day s . M i croscopi c

exam i n at i on of nerve t i ssues reveal ed no demy el i n at i on (R eed 1982). Tem e phos i n a dosage of 500 m g / kg produced a rapi d onset of l e g weakness i n chi c kens, from wh i c h survi vors recovered wi th i n 36 day s or l e ss. An i n t a ke of 125 m g / kg produced very m i l d l e g weakness, fol l o wed by prom pt

recovery . Thi s si gn was produced i n 30 day s at a dosage of 15.3 m g / kg/ day but not i n 108 day s at a l e vel of 7.4 m g / kg/ day (Gai nes et al . 1967). Thus, th e effect of t e m e phos i n chi c kens i s si m i l a r t o th at of m a l a th i on, and th e l ack of my el i n l o ss i n hens fed th e com pound
at

a di et ary l e vel of 920 ppm (about 53 m g / kg/ day ) for 30 day s , as report e d by Levi nskas & Shaffer (1970), woul d be expected (i.e., low OPIDN hazard). The subacut e and chroni c t oxi ci t y of t e m e phos i s det a i l e d bel o w. Tem e phos has been shown t o i nhi bi t Ch E activ ity in vivo . In rat s , subchroni c oral doses as l o w as 6 ppm resul t e d i n depressed red bl ood cel l C h E act i v i t y . In dogs, subchroni c oral doses of 500-700 ppm caused depressed red bl ood cel l , pl asm a , and brai n C h E activities. Subchronic oral dosing with tem e phos caused no observed effect on surviv al, food consum ption, or
t i ssue and organ hi st opathol ogy i n rat s gi ven up t o 350 ppm i n th e di et , and i n dogs gi ven 500 or 700 ppm i n th e di et for 90 day s . W e i ght gai n was reduced i n rat s gi ven 350 ppm i n th e di et . In a 30-day study wi th m a l e rat s fed 0, 250, 500, and 1000 ppm t echni cal t e m e phos, th e NOEL was 250 ppm (whi ch i s equi val e nt t o 12.5 m g / kg B

. W

. / d ay ) for any effect other th an C h E i nhi bi t i on, whi c h was not ed at al l dose l e vel s . W e i ght gai n depressi on was th e effect
not ed at 500 ppm and above. No adverse effect s were not ed at feedi ng l e vel s up t o 300 ppm i n a 2-y ear rat study

. However, ChE activities were not m easured (EPA 1981). Over a 90-day peri od, rat s t o l e rat e d a di et cont ai ni ng 9 ppm of th e sul f oxi de wi th no apparent effect except inhibition of RBC ChE activity. No inhi bition occurred at 3 ppm (Levinskas and Shaffer 1970). In a study with hum an vol unt eers, i n creasi ng doses of t e m e phos (2 t o 256 m g / d ay ) or const a nt doses of 64 m g / d ay were i ngest ed over a four week peri od. No al t e rat i ons i n red bl ood ce l l or pl asm aC h E act i v i t y and no cl i n i cal sy m p t o m s were observed (EPA 1981). The reproduct i v e and t e rat ogeni c effect s of t e m e phos are as fol l o ws. M a l e and fem a l e rat s were st art e d on diets containing 500 ppm tem e phos at m a ting. Dosage was m a intained throughout m a ting, gest ation, parturition, and lactation. There were no significant differences in num ber of litte rs produced, litter size, viability of young or
th e i n ci dence of congeni t a l defect s bet w een tr eat ed and control groups even though th e dosage caused si gns of poi soni ng i n som e rat s (Gai nes et al . 1967). In a second reproduct i on study , no com pound-rel a t e d effect s onreproduct i v e capaci t y were not ed i n rat s fed 25 or 125 ppm of t e m e phos. No effect s were not ed i n th e offspri ng (EPA 1981). Tem e phos at oral dosage l e vel s as hi gh as 2. 5 m g / kg/ day for 422 day s or at 5 m g / kg/ day for 186 day s caused no ill effects in sheep or th eir lam b s (McCarty et al. 1968). No oncogeni c effect s were not ed i n a 2-y ear study wi th rat s fed 0, 10, l 00, and 300 ppm . There exi s t s no

mu t a geni ci t y dat afor t e m e phos. The EPA R e gi strat i on St a ndard for t e m e phos st at es th at t oxi col ogi cal dat agaps rel a t e d t o reregi strat i on of t e m e phos for th e food uses are a second oncogeni ci t y study (i n m ouse) and t e rat ogeni ci t y and mu t a geni ci t y t e st i ng. Acut e t oxi ci t y (96hr-LC 50 ) of t e m e phos i n a vari et y of fi sh speci es range from 0.16 ppm (rai nbow tr out ) to 34.1 ppm (fathead m i nnow). Test cond itions and size did not appr eciably change the toxic ity of tem e phos to fish. Vari at i ons i n pH from 6.0 t o 9.0, hardness from 40 t o 162 ppm , or si ze from 1 t o 20 g gave a range of l e ss th an 4

m g /1 in 9 6 h r-LC 50 val u es. Fl ow-through t e st s for up t o 15 day s wi th cut

- th roat tr out and l a ke tr out produced TILC 50 (t i m e-i ndependent LC 50 ) val u es for t e m e phos of 0.20 and 1.05 m g / 1 (ppm ) and cumu l a t i v e t oxi ci t y i ndi ces (96hr-LC 50 val u e di vi ded by TILC 50 v a lu e) o f 5

. 0 an d 1

. 0 , resp ectiv ely. Th is in d i cates little o rn o cu mu lativ e actio n of t e m e phos i n fi sh (Johnson & Fi nl ey 1980). Fo llo win g th e treatm e n t o f th e Up p e r Vo lta Riv e r with Ab ate fo r th e co n tro l o f Simu liu m larv ae, n o fish died, but fish in the treated area were prone to easy capture. The catch per uni t effort , and th e num ber of speci es captu red i n th e 24-hr peri od fol l o wi ng tr eat m e nt , were hi gher. Evi d ent l y , subl ethal stress l eadi ng t o under- or hyper-activity, m a ke the fish an easy pr ey in nature and affect the stability of the population. W h en Abate was appl i e d t o R i ver Ot i i n Ghana t o control Si mu l i u m l a rvae, fi sh 300 m upstr eam from th e poi nt of appl i cat i on were

norm a l, whereas fish at the site of application swam errat i cal l y . Fewer num bers and sp ecies were collected in the 24-hr period following applicati on than before application, suggesting possible avoidance r eaction of fish to Abate. Exposure t o 96hr-LC 50 o f fen itro th i o n fo r 2 4 h rco m p letely in h i b ited th e learn i n g ab ility o f salm o n p e rr; Ab ate at 5

m g / l ret a rded l earni ng (M urt y , Vol

. II, 1986). Acut e oral t oxi ci t y (LD 50 ) of t e m e phos for th e bul l frog i s great er th an 2000 ppm (Sm i th 1987). Acut e oral t oxi ci t y (LD 50 ) of t e m e phos for a vari et y of bi rds ranges from 18.9 ppm (C al i f orni a quai l ) t o 270 ppm (chukar). It s di et ary LC 50 val u es range from 92 ppm (north ern bobwhi t e ) t o 894 ppm (m al l a rd duck). There are few dat aon i t s derm al t oxi ci t y . M a l l a rd duckl i ngs (12-24 hr of age) were fed di et s tr eat ed wi th t e m e phosfor 7 days and housed in either heated or unheated br ooders. High m o rtality occurre d in the 100 ppm group housed i n unheat ed brooders, but di et s cont ai ni ng up t o 10 ppm di d not affect duckl i ng survi v al (Fl e m i ng et al . 1985). A reproduct i v e study conduct e d wi th gam e -farm m a l l a rd s fed 0, 1, and 10 ppm Abat e 4E (t em ephos) di d

n o t resu lt in treatm e n t effects fo r h a tch i n g su ccess, clu t ch size, fertility, n e st atten tiv en ess o f in cu b a tin g h e n s , an d duckl i ng avoi dance behavi or. However, th e m ean i n t e rval bet w een eggs l a i d was great er for th e 10 ppm group, and duckl i ng survi v al t o 21 day s was si gni fi cant l y l o wer for both tr eat m e nt groups th an for control s (Franson et al

. 1983). There have been no publ i s hed account s of wi l d l i f e di e-offs th at have been rel a t e d t o fi el d appl i cat i ons of
t e m e phos (Sm i th 1987). However, t h e 30-day EM LD (em p i r i cal m i ni mu m l e th al dose, l o west dai l y oral dosage t h at produces 1-2 deaths over a 30 day peri od) for m a l l a rds (n - 22) i s 2.5 m g / kg per day for both sexes. The resul t i ng

cumu l a t i v e t oxi ci t y i ndex for t e m e phos i s 79.4/ 2.5 - 32, i ndi cat i ng a hi gh degree of cumu l a t i v e act i on for an organophosphat e i n bi rds (Hudson et al . 1984). 3

. Ad u lticid es

a. Pyreth ru m an d Syn th e tic Pyreth ro id s Pyreth rin I is in so lu b l e in water, h a s ap p r eciab le v a p o rp r essu re b u t an ex trem ely larg e p a rtitio n co efficien t (Ko W ) in d i catin g th at it is im m o b ile in so il an d m i g r an ts slo w ly, if at all. It is u n s tab l e in su n lig h t an d rap i d l y hy drol y zed by al kal i wi th l o ss of i n sect i c i d al propert i e s. Phot odecom posi t i on of py reth ri n I as th i n fi l m s on gl ass y i el ds 11-15 product s , none of whi c h are i n sect i c i d al or of t oxi col ogi cal si gni fi cance. Saponi fi cat i on (al k al i h y d ro1y si s) of th e py reth rum m i xture of est e r product s l i b erat es 12-16 aci ds, agai n wi th th e subsequent l o ss

o f

in secticid al activ ity. M a ny i nvert ebrat e s and m i croorgani sm s are capabl e of m e tab o lically d e to x i fyin g th is n a tu ral in secticid e. Although the levels of Pyrethrin I in wa ter, air, and soil are not known, little is expected to persist because of its phot ol abi l e and bi odegradabl e natu re. Si m i l a r t o py reth ri n I, resm ethri n decom poses rapi dl y on exposure t o ai r and sunl i ght and i s unst abl e i n alkaline m e dia. However, photolysis of the ester bond is a significant reacti on for trans- and cis-resm ethrin but apparent l y not for py reth ri n I. R e sm ethri n and other t y pe I py reth roi d s general l y y i el d a l a rge num ber and great variety of photoproducts, m o st of whic h originate from further reactions of the prim ary cleavage products. For

exam pl e, th e al cohol m o i e t y l i b erat ed on phot ol y s i s of resm ethri n degrades further t o benzy l al cohol , benzal dehy de,benzoi c aci d and pheny l acet i c aci d, th e l a t t e r contri but i ng t o th e unpl easant odor of phot odecom posed resm ethri n . The envi ronm ent a l and t oxi col ogi cal i m pact of th ese breakdown product s are unknown at th i s t i m e but due t o th e lo w rates an d q u a n tities u s ed in m o sq u ito co n tro l, th ey are n o t ex p ected to b e p a rticu l arly sig n i fican t. As wi th py reth ri n I, resm ethri n i s rapi dl y bi odegr aded by i nvert ebrat e s and m i croorgani sm s by est abl i s hed

m e tabolic pathways. Although the levels of resm ethrin in water, air, and soil are not known, little is expected to persist because of its photolab ile and biodegradable nature. Py reth ri ns are pot ent , non-sy st em i c cont act i n sect i c i d es causi ng rapi d paral y si s and knockdown wi th death

o ccu rrin g at a later stag e o f in to x i catio n . In secticid al activ ity is m a rk ed ly in creased b y th e ad d itio n o f syn e rg ists such as PBO. Pyrethrins are not phy totoxic. Although toxic to b ees, pyrethrins show less hazard than indicated by
t opi cal bi oassay s (approxi m a t e l y 1 ug/ housefl y ) due t o th ei r repel l e nt effect (Hart l e y & Ki dd 1983). Py reth ri ns are degraded i n th e envi ronm ent by sunl i ght , chem i cal hy drol y s i s and by m a ny i nvert ebrat e organi sm s vi a hy drol y t i c and oxi dat i v e m e t abol i s m . The approxi m a t e resi dual peri od fo r py reth ri ns i s 1-3 day s on pl ant s and si m i l a r short durat i on i n soi l and wat e r (SC A M P 1987). No bi ol ogi cal m a gni fi cat i on has been shown. Degradat i v e product s have not been det e rm i n ed t o be as t oxi c or m o re t oxi c th an th e parent py reth ri n com pounds. It s t oxi ci t y (96hr-LC 50 ) to crustaceans range from 11 to 42 ppb and for nontarget a quatic insects approxim a tely 1.0 ppb (Verschueren 1983). The sy nthet i c py reth roi d resm ethri n i s al so a non-sy st em i c , cont act i n sect i c i d e wi th fast knockdown si m i l a r i n act i on t o th e natu ral py reth ri ns (Hart l e y & Ki dd 1983). Al though som e t i m es formul at ed wi th sy nergi s t s (e.g., pi perony l but oxi de), resm ethri n ' s t oxi ci t y i s not enhanced i n th ei r presence (SC A M P 1987). R e sm ethri n i s not phy t o t oxi c i f used as recom m e nded. R e sm ethri n i s t oxi c t o bees, but fi el d dat ai ndi cat es th at ULV spray s of

resm ethrin are not hazardous to honeybee colonies in the area treated for adu lt m o squito control (Scourge Tech. B u l l

. 1986). Daphni a magna has an LC 50 of 0.1 ppm (48 hr), Penaeus shri m p 1.25 ppb and th e Am eri can oy st er 1.79 ppm

. Pi perony l but oxi de (3,4-m ethy l e ne-di oxy -6propy l b enzy l ( hept y l ) di ethy l e ne gl y c ol ether) i s used as a syn e rg ist in co n j u n c tio n with p y reth rin s an d p y reth ro id s su ch as resm eth r in . It is relativ ely stab le to h y d r o l ysis an d UV i rradi at i on. It i s not t oxi c t o bees or other benefi ci al i n sect s and i s degraded by i nvert ebrat e s by oxi dat i v e at t ack
on th e carbon at om of th e m e th y l enedi oxy group form i ng di hy droxy pheny l com pound. Si de-chai n oxi dat i ons al so occur. El i m i n at i on i s by gl ucosi d e or am i no aci d conjugat i ons (SC A M P 1987, Hay e s 1982).Py reth rum and th e sy nthet i c py reth roi d resm ethri n share a com m on m ode of act i on as di rect nerve t oxi ns whi c h i n t e rfere wi th nerve i m pul se generat i on vi a m odul at i on of vol t a ge-gat ed i on channel s , part i c ul arl y sodi um and possi bl y cal ci um channel s (Narahashi 1987, C l ark & B r ooks 1988). As sum m a ri zed by Hay e s (1982), py reth rum m a y be absorbed from th e gastroi n t e st i n al tr act and by th e respiratory route. It is not absorbed to a significant degree through the skin. However, allergic reactions m a y result from this route of exposure. The esters constituting pyrethru m m i xtures are rapidly detoxi fied by hydrolysis in the gastroi n t e st i n al tr act and t o som e ext e nt i n th e t i ssues of adul t warm -bl ooded ani m al s. The chry santhemu m

m onocarboxylic acid form ed is excreted in the urine. Pyrethrins or their m e tabolites are not known to be stored in the body or to be excreted in the m ilk, but no study of th e m a tter has em ployed m odern m e thods. Partly because of their ready excretion, these com pounds exhibit little clinical effect in an im als following repeated exposure to

m o d e rate d o s es, b u t th ey o rth eir m e tab o lites d o lead to liv er ch an g e s in rats. Stu d i es d e scrib e th e v e ry ex ten s iv e

m e t abol i s m th at py reth ri ns undergo, m a i n l y i n th e l i v er. Vari ous act i v e i ngredi e nt s undergo si gni fi cant l y di fferent bi otransform at i on. For exam pl e, wi th i n 48 hours of oral adm i ni strat i on of 14 C-py rethrin II to rats, 53% of the 14 C was recovered as exhal e d C 0 2 , whereas onl y 0.3% of 14 C py reth ri n I was recovered i n th at form under th e sam e ci rcum st ances. The correspondi ng proport i ons of 14 C recovered from the urine were 7 and 46%, for py reth ri ns II and I, respectively. Som e of the ora lly adm i nistered m a terial is excretedin the feces, at least partially in

m e t abol i zed form . Three com pounds have been i s ol at ed from uri n e and i d ent i f i e d by NM Rand m a ss spectra. Al l
th ree are produced by both py reth ri n I and II. Al l th ree are th e resul t of oxi dat i on of both th e aci d and al cohol i c

m o ieties leaving the m a in structure of the m o lecule intact (Elliott et al. 1972a, 1972b). So far the num erous

com pounds th at resul t from hy drol y s i s of th e est e rs have not been i d ent i f i e d. The fact th at th e m o st severe cases of poi soni ng have been report e d i n i n fant s suggest s th at ve ry y oung chi l d ren m a y not hy drol y ze th e py reth rum est e rs efficien tly. In an y ev en t, m a m m a ls sh o w ap p r o x i m a tely th e sam e su scep tib ility to in j ected p y reth rin s as d o co ld

bl ooded ani m al s, i n cl udi ng i n sect s (Gaudi n 1937). Acut e oral LD 50 val u es of py reth rum i n rat s range from 584- 1500 m g / kg, 272-796 m g / kg for m i ce and 1500 m g / kg for rabbi t (Farm C h em i cal Handbook 1988, Hart l e y & Ki dd 1983, Hay e s 1982). Lehm an (1952)
est i m at ed th at th e fat a l hum an dose m i ght be 100 gram s (1430 m g / kg) for a 70-kg m a n. Acut e derm al LD 50 val u es for rats are greater than 1500 m g /kg and for rabbits 5000 m g / kg. Derm atitis is possible in sensitive individuals from constituents of the flowers. Rats a nd dogs inhaled a concentration of 16 m g /m 3 of py reth ri ns for 30 m i n. peri odsduri ng 31 cal endar day s wi th onl y sl i ght l ung i rri t a t i on (SC A M P 1987). Inhal a t i on of py reth rum at

6000 m g /m 3 for 30 m i n. caused onl y m oderat e l ung congest i on (C arpent er et al . 1980). The subacut e and chroni c t oxi ci t y of py reth rum i s al so l o w. Groups of 12 m a l e and 12 fem a l e rat s were fed py reth ri n i n soy b ean oi l at di et ary l e vel s of 0, 200, 1,000, and 5,000 ppm for 2 y ears. The dai l y dosages were,
th erefore, approxi m a t e l y 0, 10, 50, and 250 m g / kg, resp ect i v el y . Even at th e hi ghest l e vel py reth ri n had no si gni fi cant effect on growth or survi v al . A sl i ght though defi ni t e l i v er dam a ge was observed, especi al l y at th e hi gher dosage l e vel s (Lehm a n 1965). Dogs fed py reth ri ns at a di et ary l e vel of 5,000 ppm for 90 day s showed
tr em or, at axi a , l abored respi r at i on, and sal i v at i on duri ng th e fi rst m onth of exposure (Gri ffi n 1973). Am brose & R obbi ns (1951) report e d no effect i n rat s fed py reth ri ns at a di et ary l e vel of 1000 ppm for t w o y ears, but t i ssue dam a ge and gross si gns of i n t oxi cat i on appeared at 5000 ppm

. W h en py reth ri ns were fed t o rat s at a di et ary l e vel of 1,000 or 5,000 ppm for 2 y ears, th e l i v er l e si ons i n cl uded bi l e duct prol i f erat i on and focal necrosi s of th e l i v er cel l s (Lehm a n 1965). Py reth ri ns, especi al l y sy nergi zed py reth ri ns, produced enl a rgem ent , m a rgi n at i on, and cy t opl asm i c i n cl usi ons i n th e l i v er cel l s of rat s . At a di et ary l e vel of 1,000 ppm , py reth ri ns and 10,000 ppm pi perony l but oxi de,
th e changes were wel l devel oped i n onl y 8 day s , but were not m a xi m a l

. The changes were proport i onal t o dosage and sim ilar to those produced by DDT. The effects of th e two m a terials were additive (Kim brough et al. 1968). No rel e vant pathol ogy was det ect ed i n rat s fed py reth ri ns at a di et ary l e vel of 8,000 ppm for 5 weeks (Gri ffi n 1973). Th e sen s itizin g p r o p e rty o f p y reth rin s is ap p a ren tly m o re ev id en t in h u m an s th an in o th e r an im al vert ebrat e s (Hay es 1982). W h en 200 peopl e (177 wom e n and 23 m e n) were pat c h t e st ed wi th a 1% wat e r di spersi on of py reth ri ns, no evi d ence of pri m ary i rri t a nc y or of sensi t i zat i on was found (unpubl i s hed report ci t e d by FAO/ W HO 1971). It mu st be not ed, however, th at both th e formul at i on used and th e durat i on of exposure were different from those that have caused th e m o st severe derm atitis or sensitivity of any kind under practical conditions of exposure. There is little doubt that com m e rcially ava ilable pyrethrin extracts are less sensitizing than native py reth rum . However, apparent l y no study has been m a de t o m easure th e di fference i n way th at woul d be
st at i s t i cal l y val i d . M i t c hel l et al ., (1972) found al l th e act i v e i ngredi e nt s of py reth rum , except py reth i n II, t o be inactive on patch test in a patient who had a history of a llergenic derm atitis to pyreth rum and who reacted positively
t o py reth rum fl ower heads, powder extr act s of th e pl ant , and py reth rosi n. The no-effect l e vel corresponds t o a rat e of 3600 m g /m an/ d ay (SC A M P 1987).Pyrethrum has little or no reproductive or teratoge nic hazard (Hayes 1982). Rabbits that received p y reth rin s o r ally o n d a ys 8 to 1 6 o f g e statio n at d o s ag es as h i g h as 9 0 m g /k g p r o d u ced litters with n o statistical increase in abnorm a lities (unpublished report cited by FAO/W HO 1971). W h en rats were fed pyrethrins at a dietary l e vel of 5,000 ppm begi nni ng 3 weeks before fi rst m a t i ng, reproduct i v e perform ance was not reduced, but th e wei ght s of weanl i ngs were si gni fi cant l y l o wer th an those of control s (Gri ffi n 1973). The sy nthet i c com pounds are m o re phot ost abl e, som e t i m es provi di ng control for m a ny weeks fol l o wi ng a si ngl e fi el d appl i cat i on. In addi t i on, som e of th e sy nthet i c py reth roi d s are m e t abol i zed m o re sl owl y by both i n sect s

an d m a m m a ls an d h e n ce h a v e in creased to x i city. En h a n ced en v i ro n m en tal an d b i o l o g i cal stab ility o f th ese

com pounds have tr i ggered needs for resi due anal y s i s a nd for underst a ndi ng th ei r pot ent i a l t oxi ci t y t o m a m m a l s (M arqui s 1986). R e sm ethri n was one of th e fi rst or "earl y " py reth roi d sy nthesi zed whi c h i s not hal ogenat e d nor does i t cont ai n a cy anophenoxy benzy l al cohol . Thus, i t s m e t abol i s m and pharm acoki net i c s are m o re si m i l a r t o th e p y reth rin s th an th e m o re stab le typ e II p y reth ro id s (e.g ., fen v a leratte, cyp e rm eth r in , d e ltam e th rin )

. Resm ethrin has an acute oral LD 50 ο f 2700 m g / kg i n rat s and 4250 m g / kg i n rat s exposed t o t echni cal

resm ethri n (SB P -1382). The derm al LD 50 val u e i n rabbi t s i s great er th an 2000 m g / kg and great er th an 3000 m g / kg i n rat s . R e sm ethri n was found t o be non-i rri t a t i ng t o ski n and ey es (rabbi t s ). SB P1382 i s cl assi fi ed as a very m i l d conjunct i v al i rri t a nt . The i nhal a t i on (4 hr) for rat s and dogs i s est abl i s hed at great er th an 9.49 g/m 3 . No effect level was 420 m g /m 3 (4 hr). The NOEL i n rat s for a subchroni c i nhal a t i on study (90 day s ) i s 0.1 g/m 3

. In 90 day feeding trials, rats receiving 3000 m g resm ethrin/kg diet showed no ill effects. The NOEL (no observabl e effect l e vel ) for resm ethri n i n a 180-da y subchroni c feedi ng study i n dogs i s 10 m g / kg/ day

. In th ree generat i on reproduct i on t e st s for resm ethri n , th e NOEL for rat s i s 500 ppm . No t e rat ogeni c effect s are observed in rats receiving resm ethr in at dosages up to 80 m g /kg/day, up to 25 m g /kg/day for rabbits and up to 50 m g / kg/ day for m i ce. The NOEL for fet o t oxi ci t y i s 40 m g / kg/ day

. Although lim ited, two studies support the contention that resm ethrin has little carcinogenicity hazard. In an 85-week m ouse feedi ng/ oncongeni ci t y study , SB P-1382 was not oncongeni c at 1000 ppm . In a 2-y rrat chroni c feedi ng/ oncognei c i t y study , SB P-1382 was not oncogeni c at 5000 ppm , th e hi ghest dose t e st ed. The above dat a have been com p i l e d from th e fol l o wi ng sources: Hart l e y & Ki dd 1983, W o rthi ng & W a l k er 1983, SC AM P 1987,Peni ck-B i o UC LAF C o rp. 1986. Al though overal l evi d ence for chroni c t oxi ci t y i n m a m m a l s i s l i m i t e d, p y reth rin / p y reth ro id s still rep r esen ts o n e o f th e safest classes o f p e sticid es p r esen t av ailab l e. Because piperonyl butoxide (PBO) is included in various pyreth rum and pyrethroid (i.e., resm ethrin) product s used for m o squi t o control , th e fol l o wi ng m a m m a l i a n t oxi col ogy i s i n cl uded. The acut e oral t oxi ci t y (LD 50 ) for PB O i n vari ous m a m m a l range from 3800 m g / kg (m ouse) t o 11,502 m g / kg i n rat
. Derm al LD 50 for PBO in rabbit is greater than 1880 m g /kg. Although derm al ab sorption is poor, mu ltiple i nunction at 200 m g /kg m a y be fat a l t o ani m al s. In a subchroni c feedi ng study , rat s t o l e rat e d wi thout harm ful effect s 5000 ppm i n th e di et for 17 weeks; 10,000 ppm were endured through 3 successive generations with m odera te toxic effects and; 25,000 ppm in the diet were fatal to rats in from 4 to 46 weeks. In 2-yr chronic feeding trials , rats receiving 100 m g /kg diet suffered no ill-effect. PBO is noncarcinoge nic and the safe hum an tolerance for chronic ingestion is estim ated at 42

m g / kg di et (Negherbon 1959, W o rthi ng & W a l k er 1983). Py reth ri ns (py r ethrum ) are hi ghl y t oxi c t o fi sh (Hart l e y & Ki dd 1983). Acut e t oxi ci t y of py reth rum as judged by 96hr-LC 50 ranged from 13 ppb (channel catfish) to 58 ppb (b luegill). Tem p erature and pH of test

so lu tio n s affected th e b i o l o g i cal activ ity o f n a tu ral p y reth ri ns. Toxi ci t y t o channel cat fi sh was 12-fol d hi gher at 18 ° C than at 12 ° C. Toxicity increased in aci d wat e r (l ow pH); th e 96hr-LC 50 for bluegills was 41 ug/l (ppb) at pH 6.5 and 87 ug/l (ppb) at pH 9.5. W a ter hardness (44- 314 ppm ) had little influence on toxic ity (Johnson and Finley 1980). Excel l e nt control of l a rvae of Cx. ta rsa lis i n experi m e nt al ponds was obt ai ned at th e rat e of 1 py reth ri n to ssits/ m 2 (4 4 B ai/h a). At th e sam e rate, satisfacto r y co n tro l (9 2 % ) o f C x . peus l a rvae was obt ai ned i n dai r y wast e-wat e r l a goons i n R i versi d e C ount y , C a . At th e effec t i v e m o squi t o l a rvi c i d al rat e (44 g/ ha), m o squi t o fi sh, G.

a ffin is , was affected when som e tossits we re placed with the fish in 0.9 m 3 screened cages. Five successive weekly
tr eat m e nt s of G. a ffin is at th e l a rvi c i d al rat e and doubl e th at rat e (44 and 88 g/ ha) resul t e d i n 37% and 67 % reduct i on of fi sh y i el d harvest e d 42 day s aft e r th e fi rst tr eat m e nt com p ared t o th e y i el d obt ai ned from th e untreat ed ponds (control s ), respect i v el y . No m a rked effect s on som e of th e non-t a rget organi sm s such as dragonfl y nai a ds,
ostr acoda, copepods, and Di xa m i dge l a rvae were not ed. M a y f l y nai a ds were el i m i n at ed at al l rat e s appl i e d, but recovered wi th i n 2-3 weeks aft e r tr eat m e nt
. Py reth roi d s have very hi gh i n sect i c i d al act i v i t y a nd have found wi de use i n th e l a st few y ears. Though th ey are n o t p e rsisten t in th e en v i ro n m en t, th eir acu te to x i city to fish is h i g h

. Th e cyan o - su b s titu tio n o f th e phenoxy benzy l al cohol m o i e t y (as i n cy perm ethri n and fenval e rat e ) enhances th e t oxi ci t y of py reth roi d s t o fi sh.Si m i l a rl y , py reth roi d s wi th (l R )-ci s -i som e rs for th e aci d m o i e t y are m o re l e th al th an th e correspondi ng ci s-,transracem ates. Fenvalerate and perm ethrin are m o re toxic than m a ny OC com pounds, the 96hr-LC 50 bei ng 0.5 t o 12.0 ug/ l (ppb). C o l d wat e r fi sh were report e dl y m o re suscept i b l e th an warm wat e r fi sh t o natu ral perm ethri n s as wel l as syn th e tic p y reth ro id s. Py reth roi d s are m e t abol i zed i n fi sh by both hy drol y t i c and oxi dat i v e processes. It appears th at , i n general , est e rases are m o re i m port a nt i n m e t abol i z i ng th e tr ans-chry santhem a t e s of pri m ary al cohol s whereas oxi dases are

m o re i m port a nt wi th th e ci s-chry santhem a t e s of pri m ary al cohol s. Py reth roi d s are rapi dl y m e t abol i zed by fi sh (M urt y , Vol

. II 1986). R e sm ethri n (SB P -1382) i s t oxi c t o fi sh (Hart l e y & Ki dd 1983) wi th an acut e t oxi ci t y (96hrLC 50 ) to freshwater fish ranging from 1. 7 ppb (lake trout, bluegill) to 16. 6 ppb (channel cat fish) (Johnson and Fi nl ey 1980). R e sm ethri n has a 96hrLC 50 val u e of great er th an 150 ppb for coho sal m on (Verschueren 1983). Resm eth r in was th e least to x i c p y reth ro id ag ain s t fro g s ( Rana pi pi ens pi pi ens ) wi th a subcut aneous LD 50 val u e of great er th an 60 ppm (C ol e and C a si da 1983). The acut e oral t oxi ci t y of resm ethri n t o C a l i f orni a quai l has been det e rm i n ed t o be mu ch great er th an 2000 ppm (Johnson and Fi nl ey 1980). b

. Malath io n Malathion is a non-system ic insecticide and acaricide that acts as a cholinesterase inhibitor. It is generally non-phy t o t oxi c but m a y dam a ge gl asshouse cucum b er, beans a nd cert a i n ornam e nt al s. Som e vari et i e s of appl e, pear and grape m a y al so be i n jured (Hart l e y & Ki dd 1983). It s approxi m a t e resi dual peri od on pl ant s i s 5-10 day s but has a short resi dual t i m e i n soi l s . M a l a th i on i s rapi dl y degraded in vitro b y saltm arsh b acteria to m a lath io n

m onocarboxy l i c aci d (m onoaci d), m a l a th i on di carboxy l i c aci d (di aci d) and vari ous phosphothi onat e s as a resul t of carboxyesterase cleavage. In addition, som e expect ed phosphatase activity produces desm ethyl m a lathion, phosphom ono- and phospho-di th i onat e s, 4-carbon di carboxy l i c aci ds and th e correspondi ng ethy l e st ers (Verschueren 1983). In insects, m a laoxon is the m a jor m e tabolite form ed by oxidative de sulfuration at about 25% of al l t o t a l

. Predom i n ant degradat i on i s caused by hy drol y s i s i n i n sect s (Ai zawa 1982). B i ol ogi cal m a gni fi cat i on of

m a l a th i on i s not l i k el y (SC A M P 1987). M a l a th i on present s som e t oxi ci t y t o benefi ci al i n sect s i n cl udi ng honey bees (Hart l e y & Ki dd 1983). The
t opi cal LD 50 for honey bees i s 0.71 ug/ bee (SC A M P 1987). The 96 hr-LC 50 for non-t a rget aquat i c i n sect s rangefrom 1.1 to 10 ppb, and for crustaceans 0.76 ppb to 3000 ppb. The m e dian tolerance lim it (TLm ) for the Am erican oy st er i s 9070 ppb (48 hr) for egg and 2600 ppb (14d) for l a rval (Verschueren 1983). Degradat i on of m a l a th i on i n soi l i s qui t e rapi d. It was found th at aft e r th e appl i cat i on of m a l a th i on at 5 l b / acre onl y 15% of th e appl i e d dosage was recovered 3 day s l a t e r. Aft e r 1 week, 95% of th e appl i e d m a l a th i on had di sappeared. In Ludhi ana, Pal a m put , and Kam m asoi l s , m a l a th i on was 100% degraded 4 day s wi th hi gher
t e m p eratures produci ng m o re rapi d degradat i on (Lavegl i a& Dahm 1977). W a lker & Stojanovic (1973) also found that m a lathi on was quite stable under neut ral or acid pH conditions

an d th at su scep tib ility to h y d r o l ysis in creased with in creasin g alk a lin ity. Th ey d e m o n s trated th at m a lath io n disappeared m o re rapidly under nonsterile than sterile conditions and indicated that m a lathion disappearance is
st i mul at ed by vari ous m i crobi ol ogi cal sy st em s i n soi l

. Under st eri l e condi t i ons, th e observed m a l a th i on rem a i n i ng i n th e Tri n i t y l o am , Okol ona cl ay , and Freest one sandy l o am aft e r 10 day s of i n cubat i on was 91%, 77% and 95%, respect i v el y . In nonst e ri l e soi l , com p l e t e di sappearance of m a l a th i on had occurred. Get z i n and R o sefi el d studi ed the degradation of m a lathion in nonste rile, heat-sterilized, and gam m a -sterili zed soil. After 1 day, 97% of the

m a l a th i on was degraded i n th e nonst e ri l e soi l , 90% i n th e i rradi at ed soi l , and onl y 7% i n th e aut o cl aved soi l

. Because of the rapid degradation in nonsterile soil, it was suggested that m i croorganism s were partly responsible for
th e degradat i on of th e com pounds. The di fference bet w een th e am ount of m a l a th i on decom posed i n i rradi at ed soi l and aut o cl aved soi l was at tr i but ed t o nonvi abl e , heat -l ab i l e subst a nces. A st abl e , heat -l abi l e enzy m e , whi c h catalyzed th e h y d r o l ysis o f m a lath io n to its m o n o acid , was p a rtially p u r ified

. Th is esterase was ex tracted fro m i rradi at i on-st eri l i zed soi l as wel l as from noni rradi at ed soi l

. W h en th e part l y puri f i e d enzy m e was appl i e d t o th e soi l , i t possessed m a ny of th e charact eri s t i c s necessary for prol onged act i v i t y i n a cel l -free st at e i n soi l

. It was l e ss heat-labile than m o st enzym e s, lost little or no activity upon prolonged storage, and survived desiccation in the soil. There have been m a ny report s of m i croorgani sm s m e t abol i z i ng m a l a th i on t o vari ous product s . C a rboxy est e rase act i v i t y , whi c h degrades m a l a th i on t o i t s m onoaci d and di aci d, i s th e predom i n ant degradat i v e path way . Phosphat a se act i v i t y al so has been report e d. Oxi d at i v e de sul f urat i on and dem e th y l at i on seem t o be rath er m i nor

m e t abol i c rout es (Lavegl i a& Dahm 1977). W a l k er (1976) report e d th at m a l a th i on di ssi pat e d rapi dl y i n both st eri l e and nonst e ri l e wat e r i n th at onl y 3 % o f th e ad d e d in secticid e co u l d b e d e tected after 1 8 d a ys in cu b a tio n . Th e sim ilarities b e tween m a lath io n degradat i on i n th e presence and absence of bi ol ogi cal l y ac tive system s dictates that m a l a th i on di sappearance i s bypurely chem ical m echanism s . The eff ect o f salin ity o n th e d e g r ad atio n o f m a lath io n in estu arin e water was d e term in ed b y in cu b a tin g th e in secticid e in sterilized seawater v a ryin g in salin ity fro m O to 2 5 p p t . Th e degradat i on of m a l a th i on was found t o be di rect l y proport i onal t o th e l e ngth of i n cubat i on and t o i n creasi ng sal i n i t y in th is sterile system in d i cati ng di rect chem i cal hy drol y s i s . The organophosphat e i n sect i c i d es i n cl uded i n th i s cl assi fi cat i on share a com m on m ode of act i on as pot ent i ndi rect nerve t oxi ns vi a i nhi bi t i on of chol i n est e rases (C hE).

Acetylch o lin e (ACh ), th e n e u r o tran s m itter secreted b y ch o lin erg i c n e u r o n s , allo ws fo r ch em ical
tr ansm i ssi on of nerve i m pul ses across th e sy napse. Acet y l chol i n est e rase (AC h E) i s th e enzy m e responsi b l e for th e breakdown of AC h, th ereby t e rm i n at i ng th e el ect ochem i cal connect i on bet w een t w o nerve cel l s . Organophosphorus insecticides (OP) phosphorylate AChE in an irreversible reac tion that inhibits the activity of AChE to hydrolyze the
neurotransm itter at the nerve synapse. The accumu lation of ACh results in continuous nerve firing and eventual fai l u re of nerve i m pul se propagat i on. R e spi r at ory paral y si s is generally the im m e diate cause of death. Brain ChE
act i v i t y i s used i n th e di agnosi s of OP poi soni ng wi th a reduct i on of 20% of norm a l act i v i t y i ndi cat i ng exposure. A ChE inhibition of 50% or m o re is considered the diagnostic threshold for determ ining th e cause of death. Because

o f

th e irrev e rsib le n a tu re o f th e p e sticid e-en zym e b i n d i ng react i on charact eri s t i c of OP poi soni ng, recovery from a subl ethal OP exposure depends on sy nthesi s of m o re C h E. There i s evi d ence th at recovery of C h E act i v i t y i n pl asm ai s as fast or fast er th an i n th e brai n (Hay es 1982). In ad d itio n to an tich o lin esterase activ ity, so m e OP p e st i c i d es have other adverse bi ochem i cal effect s. A

num ber of have been det e rm i n ed t o i nhi bi t neurot oxi c est e rase, an enzym e that has not been isolated and whose bi ochem i cal and phy si ol ogi cal funct i ons i n nerve t i ssue are unknown (M et cal f 1982). Organophosphat e -Induced Delayed Neuropathy (OPIDN) has been recently reviewed (Marquis 1986). Little inform ation is available on del a y e d neurot oxi ci t y i n wi l d l i f e speci es. However, speci es differences can be great and the capacity to produce del a y e d neurot oxi ci t y i s wi despread am ong OP (M et cal f 1982). Other subl ethal bi ochem i cal effect s have been desc ri bed for OP, such as i m pai r ed reproduct i on i n bi rds
th rough possi bl e horm onal effect s and reduced t o l e rance t o col d stress (R at t n er et al . 1982a, 1982b). Em bry o t oxi ci t y and t e rat ogeni c effect s have been dem ons tr at ed for som e OP (Hoffm an & Al bers 1983), and som e have been shown t o cause changes i n broodi ng behavi or or ne st at t e nt i v eness of bi rds whi c h coul d resul t i n death ofth e y oung (Grue et al . 1983, Sm i th 1987). C e ntral nervous sy st em t oxi ci t y and nonchol i n ergi c effect s of OP i n

m a m m a ls have been recently reviewed by Marquis (1986). As sum m a ri zed by Hay e s (1982), th e m o st stri ki ng di fference bet w een th e m e t abol i s m of m a l a th i on and
th at of th e m a jori t y of organi c phosphorus com pounds used as i n sect i c i d es depends on th e presence of t w o carboxy groups i n m a l a th i on. M a l a th i on i s subject t o th e vari ous ki nds of m e t abol i s m th at other organi c phosphorus insecticides undergo, but the splitting of either carboxyester linkage renders th e com pound non-toxic. Details of the

m e t abol i s m have been report e d by O' B r i e n (1960) and by Heath (1961). The excret i on of absorbed m a l a th i on i s rapi d. W h en 25 m g of 14 C-lab e led m a lath io n was ad m i n i stered to each of six m a le rats, activity appearedin the urine within 2 hr, and 91.72% was elim inated within 24 hr while an ad d itio n a l 7

. 7 5 % rem a in ed in th e g a stro in testin al co n t en ts . Excret i on was m a i n l y vi a th e uri n e (83.44%) and part l y by the feces (5.51%), but 2.77% was exhaled as carbon dioxide. No unm etabolized m a lathi on could be detected 8 hrs aft e r dosi ng (B ourke et al . 1968). In i n vi tr o studi es of hum an and rat l i v er, no i m port a nt di fference was found in ability to degrade m a lathion (Matsumu ra & W a rd 1966) c oncentrations of 1 ug/l (ppb) of m e thoxychlor or MDE, Daphni a exposed for th ree generat i ons grew and reproduced norm a l l y , but th e em ergence of m a y f l y ny m phs was drast i cal l y reduced. In ponds tr eat ed wi th 10 t o 40 ug/ l (ppb) of m e thoxy chl o r, th e t o t a l num ber of benthi c organi sm s i n creased and speci es com posi t i on changed wi th chi r onom i d s becom i ng th e dom i n ant speci es. Nei th er survival nor growth of bluegills in the treated ponds was affected. However, m o st of the fish exam ined showed nonspecific liver degeneration and an accu mu lation of a mu co- or glyco-protei naceous m a terial inside the m a jor bl ood vessel s . R e gressi on of th ese effect s had occurred by 56 day s aft e r tr eat m e nt (Johnson & Fi nl ey 1980). Greater sensitivity of young striped mu llet than older juveniles to m e thoxychlor has been reported. Adult
stri ped mu l l e t s had l a rger am ount s of th e resi dues, owi ng t o th e presence of a rel a t i v el y hi gher percent a ge of body fat in th e ad u lt wh en co m p ared with th e j u v e n iles. Th at it is th e lip id co n t en t th at confers a greater degree of
t o l e rance of th e l a rger fi sh t o th e DDT-t y p e com pounds i s confi r m e d by th e t oxi c concentr at i ons of DDT, endri n , and m a l a th i on, t o brook tr out , cut

- th roat tr out , and coho sal m on of 1-g si ze and 1- t o 2-g si ze. W i th DDT and

en d r in , th ere was red u c tio n in th e to x i city with in -crease in size, whereas no such diffe ren ce in th e to x i city o f

m a l a th i on t o sm al l e r and l a rger fi sh was found. Exposure t o a 96hr-LC 50 val u e of feni tr othi on for 24 hr com p l e t e l y in h i b ited th e learn i n g ab ility o f salm o n p a rr an d Ab ate at 5 m g /l retard ed learn i n g . DDT (OC) at 0

. 0 7 m g /l m ild ly enhanced l earni ng whereas m e thoxy chl o r had no effect (M urt y , Vol II, 1986).Organophosphat e i n sect i c i d es have negl i g i b l e chroni c t oxi ci t y , but som e have m oderat e t o hi gh acut e to x i city in fish . Th e 9 6 h r-LC 50 of several organophosphat e com pounds t o vari ous speci es of North Am eri can fresh water fish are listed b e lo w: The acute toxicity (96hr-LC 50 ) of m a l a th i on for a vari et y of fi sh speci es ranged from 62 ppb (red ear sunfish) to 12,900 ppb (black bullhead). In lake trout, fry (0 .3 g) were twice as sensitive as fingerlings (4.5 g) to

m a lathion. An increase in tem p erature from 10 ° to 2 1 ° C caused an 11-fol d decrease i n t oxi ci t y t o th e daphni d Si mocephal us . However, an increase from 7 ° to 2 9 ° C cau sed a fo u rfo ld in crease in to x i city to b l u e g ills. Variatio n s i n wat e r hardness di d not appreci abl y al t e r th e t oxi ci t y t o fi sh or i nvert ebrat e s. M i xtures of m a l a th i on wi th B a y t ex (fenthi on), parath i on, EPN, Perthane (eth y l an), or carbary l were sy nergi s t i c i n th ei r t oxi ci t y t o rai nbow tr out and b l u e g ills. Co m b in atio n s o f m a lath io n with DDT o rto x a p h e n e were o n l y ad d itiv e. Malath io n h a s m o re-th a n additive toxicity with m o re than half of the pesticides with which it was com b ined (Murty 1986) and is no longer used as a larvicide in Massachusetts. Organophosphate com pounds, because of their relativel y higher water solubility, are in general taken up
t o l e sser ext e nt th an organochl ori n es and el i m i n at ed fast er. The t i m e for achi e vi ng th e hi ghest l e vel s of upt ake and
th e ext e nt of ret e nt i on of OP resi dues by fi sh was di rect l y rel a t e d t o th e ext e nt of persi s t e nce of a com pound i n wat e r. M o t s ugo fi sh exposed t o 0.6 t o 1.2 ppm m a l a th i on, at t a i n ed th e hi ghest body concentr at i ons 2.4 m g / kg of

m a l a th i on aft e r 1 day

. No m a l a th i on resi dues were found 24 hr aft e r th e exposure of pi nfi s h t o 75 ppb
concentr at i on. Onl y m a l a th i on m onoaci d was recorded i n th e gut (M urt y 1986). W i th DDT and endri n , th ere was red u c tio n in th e to x i city with in crease in size, wh ereas n o su ch d i fferen ce in th e to x i city o f m a lath io n to sm aller an d l a rger fi sh was found. The natu ral degradat i on product s of pest i c i d es, i n general , are l e ss t oxi c th an th e parent

com pounds. But occasionally, the prim ary degradation produc t m a y be m o re toxic. The hydrolysis product of

m a l a th i on, di ethy l fum a rat e , was m o re t oxi c th an th e parent com pound t o th e fath ead m i nnows (M urt y 1986). Acut e oral t oxi ci t y (LD 50 ) of m a l a th i on i s 4100 m g / kg for rabbi t s and great er th an 4000 m g / kg for rat s (Hart l e y & Ki dd 1983, W o rthi ng & W a l k er 1983, Sm i th 1987). B a sed upon th e l o w t oxi ci t y of th i s com pound, i t woul d appear th at a t i m e-wei ght ed average TLV of 10

m g /m 3 i s suffi ci ent l y l o w t o prevent sy st em i c effect s (Hart l e y & Ki dd 1983). W o rkers exposed t o 84.8 m g /m 3 experienced m oderate eye irritation (SCAMP 1987). Hollingsworth has established a VSR for m a lathion of 38 (W i l k i n son 1976).Under subacut e and chroni c experi m e nt al condi t i ons, m a l a th i on has been fed t o rat s for 104 weeks at l e vel s as high as 5000 ppm in the diet with no gross effects. In 1.75 yr trials rats receivi ng 100 m g tech./kg diet showed

norm a l wei ght gai n . There was no effect found on bl ood C h E when m a l a th i on was fed t o hum an vol unt eers for 47 day s at th e rat e of 16 m g /m an/ d ay . Vol unt eers dosed derm al l y showed no change of bl ood C h E or other i n jury while exceeding an average of 47 m g /m an /day and a m a ximu m of 220 m g /m an/day. W h ereas there is no evidence that m a lath io n is terato g e n i c in m a m m a ls, it d o e s cau se a ch aracteristic sy ndrom e of deform i t y i n chi c kens th at apparent l y de pends on tr y p t ophan m e t abol i s m and m a y be pecul i a r t o th e egg, whi c h i s cl osed sy st em (Hay es 1982). W h en 1.17 t o 29.20 m g of m a l a th i on was i n ject ed di rect l y i n t o th e y o l k of each egg, it often killed the em bryo and deform ed m a ny of those that survived. W h en inj ections were m a de on day s 8 t o 12, hal f of th e survi vors l acked feathers or had onl y a few feathers on th e abdom i n al regi on. W h en i n

ject i ons were m a de on day s 6 or 7, 95% of th e survi vor s were sm aller th an n o r m a l. W h en in j ectio n s were m a d e on day s 4 or 5, th e l e gs were hal f th e proper si ze a nd th e phal a nges were perm anent l y fl exed i n 95% of th e

su rv iv o r s, an d th e m a x illa was cu rv ed d o w n w ard o v e r th e sh o r ten e d m a n d i b l e in 5 0 % o f cases. All o f th e h a tch e d chi c ks had abnorm a l feathers, and som e l acked feathers com p l e t e l y or i n som e areas. M o st of th e hat c hed chi c ks were about t w o-th i r ds norm a l si ze, and 6% were onl y one-fourth norm a l si ze (Greenberg & LaHam 1969). Try p t ophan prevent e d th e hi nd l i m b, beak, and feather def ect s and overal l growth ret a rdat i on i n m a l a th i on-dosed

em bry o s (Greenberg & LaHam , 1970). Appl i cat i on of 0.1 m l of 0.2 M ni cot i n am i d e or 0.1 m l of 0.1 M tr y p t ophan si mu l t a neousl y wi th m a l a th i on prevent e d devel opm ent of th e sy ndrom e i n al l survi vors, al though th e ni cot i n am i d e increased m o rtality. Tryptophan was also effective when injected into the yolk, and it was not toxic. It was specul a t e d th at m a l a th i on i n t e rferes wi th m obi l i zat i on of tr y p t ophan from y o l k prot ei ns, consequent l y decreasi ng sy nthesi s of ni cot i n am i d e, whi c h i s essent i a l for py ri di ne nucl e ot i d e-dependent react i ons i nvol ved i n di fferent i a t i on of legs, beak, feathers, and other organs . Deform ities of chicks can also be produced by feeding m a lathion to laying hens for 3 weeks at di et ary concentr at i ons up t o 600 ppm (Ghadi ri et al . 1967). However, th e m o st l i k el y probl em for poul tr y i s not t e rat ogeni ci t y but si m p l e t oxi ci t y . Th e h a tch ab ility o f eg g s was red u ced wh en th e h e n s were fed d i etary lev e ls o f 1

. 0 p p m o rh i g h e r b u t n o t 0.1 ppm (about 0.0058 m g / kg/ day ) (Saut e r & St eel e 1972).Al though m a l a th i on has been report e d t o produce del a y e d neuropathol ogi cal sy ndrom e i n a hum an suicide attem p t (Hierons & Johnson 1978), these findings ar e not substantiated in m o re sensitive anim al m odels (Hay es 1982). No n e o f th e 8 mu tag e n i city stu d i es rep o r ted in NCI were p o s itiv e fo r m a lath io n . In g e n e ral carci nogeni ci t y / oncogeni ci t y studi es carri ed out by NC I, m a l a th i on was not i m pl i cat ed as a carci nogen (personal

co m mu n i catio n , Pesticid e Bu reau , DFA, Bo sto n , MA). IARC co n c lu d e d th at m a lath io n an d its m e tab o lite

m a l a oxon were t e st ed for carci nogeni ci t y i n m i ce and rat s by adm i ni strat i on i n th e di et . No evi d ence of carci nogeni ci t y was found. M a ddy (1984) ranks m a l a th i on i n cat egory 3 (negl i g i b l e oncogeni c pot ent i a l , controversy as t o any such pot ent i a l , or not oncogeni c). Salm onids exposed to 120 to 300 ugtl (ppb) m a lath ion showed AChE inhib ition of 70 to 80%, and
act i v i t y i ndi ces were reduced by 50 t o 70% of th at of une xposed fi sh. Gol d fi sh exposed t o subl ethal l e vel s of

m a l a th i on showed a si gni fi cant l y reduced frequency of avoi dance response at l e vel s bel o w th at causi ng a reduced AC hE act i v i t y . One-hour bath exposures of rai nbow tr out t o subl ethal l e vel s of m a l a th i on caused severe t i ssue dam a ge to the gills and m i nor nonspecific liver lesions. Ponds given four sem i -m onthl y treatm e nts during May-July at levels up to 0.02 m g /1 (20 ppb) produced no discerni ble effects on resident bl uegill and channel catfish popul at i ons. Aquat i c i n sect popul at i ons were si gni fi cant l y de pressed at th e hi gh tr eat m e nt l e vel but not at

th e l o wer l e vel s (Johnson & Fi nl ey 1980). Irrespect i v e of th e exposure t i m e and exposure concen tr at i on, th e AChE act i v i t y of dy i ng pi nfi s h was reduced by 72 t o 79%. Enzy m e i nhi bi t i on was hi gher i n l e th al exposures th an i n subl ethal exposures. The observed correl a t i on bet w een brai n AC hE act i v i t y and deaths was consi d er ed t o be of di agnost i c val u e. Aft e r 3.5, 24, 48, or 72-hr exposure to 575, 142, 92, and 58 ppb of m a lathion, 40 to 60% of the pinfish died a nd the extent of inhibition of AC hE was i n th e range of 72 t o 79%. Fol l o wi ng th e e xposure of brook tr out and rai nbow tr out t o m a l a th i on, th e Ach E lev e ls were ap p r o x i m a tely 2 4 an d 2 8 % o f th o s e o f th e co n tro ls, an d th e fish h a d less th an o n e th ird th e ab ility of th e control s t o do work. Thus m a l a th i on, though not di rect l y and i m m e di at el y t oxi c, had a del e t e ri ous effect , owing to the im pairm e nt of the ability of the fish to m a intain equilibrium , to search for food, and to avoid predators (M urt y 1986). In th ei r exam i n at i on of popul at i on and C h E responses i n W a l l e y e exposed t o m a l a th i on aeri a l spray s , Lockhart et

al . (1985) found th at chol i n est e rase ac t i v i t y fel l t o about 25% of prespray val u es wi th i n 12 hr aft e r th e fi rst spray , and th en gradual l y recovered t o about 80% of prespray val u es over 2 weeks. The sam e pat t e rnwas evident after the second spray, but the inhibition of ChE activity was not quite as large. Fish captured for anal y s i s showed no i ndi cat i on of th e sy m p t o m s of OP poi soni ng. The popul at i on st at i s t i c s i ndi cat ed sm al l
t e m porary decreases i n both cat ch per uni t effort and wei ght g a in s after th e first sp ray. Ev id en tly a red u c tio n in C h E act i v i t y t o about 25% of preexposure l e vel s was th e approxi m a t e th reshol d for popul at i on effect s caused by

m a lath io n . The acute oral toxicity (LD 50 ) of m a l a th i on t o vari ous speci es of bi rds range from not t oxi c at 100 ppm (European st arl i ng, red-wi nged bl ack bi rd) t o 1485 ppm for m a l l a rd duck. Di et ary LC 50 val u es range from 2639 ppm (ri ngnecked pheasant ) t o great er th an 5,000 ppm for m a l l a rd duck. Acut e derm al LD 50 values are not available (Sm i th 1987). Malath io n ap p lied at 0

. 6 to 1

. 1 k g / h a(0 .5 to 1

. 0 lb /acre) resu lted in n o o b s erv e d m o rtality o f wild b i rd s in
one study conduct e d, and bi rd count s aft e r spray i ng were ei th er hi gher or nearl y th e sam e as before spray i ng (B l ack & Zorb 1967). At appl i e d rat e s of 852-1140g m a l a th i on/ ha (12-16 oz/ acre) t o fi el ds cont ai ni ng caged quai l , no evidence of m o rtality or population changes of wild bi rds were observed (Sm ith 1987). After m a lathion was aerially applied to a forested watershed at the rate of 0.81 kg/ha, birds reacted to th e spraying for 2 days without lasting effects and no effects on rep tiles and am phibians were observed. However, populations of m i ce and chi p munks were report e dl y reduced by at l east 30% (Gi l e s 1970). Tadpol es exposed t o 5 m g / 1 (5 ppm ) m a l a th i on through a continuous-flow apparatu s did not bioaccumu late levels that were toxic when fed to 2-week-old m a llard duckl i ngs i n a si ngl e m eal (Hal l & Kol b e 1980). The predi c t e d bi oconcentr at i on fact or (B C F ) for m a l a th i on i s l o w. Thus, m a l a th i on has m oderat e t o sl i ght acut e oral t oxi ci t y t o bi rds and th ere are no publ i s hed report s of wild life d i e-o ffs th at can b e attrib u t ed to th e u s e o f m a lath io n . Its p e rsisten ce an d to x i city to b i rd s is relativ ely lo w. However, m a l a th i on' s t oxi ci t y has been report e d t o be pot ent i a t e d by EPN tr eat m e nt (M urphy 1969), and th e i n t e ract i on of th ese and other pest i c i d es i s not ful l y underst ood (Sm i th 1987). B

. B i ol ogi cal C ontrol

. 1. Intr oduct i on B i ol ogi cal control i n cl udes at t acks on th e pest speci es by other speci es and m a ni pul at i on of th e pest speci es i t s el f. The form er i n cl udes th e tr adi t i onal bi ol ogi cal control agent s , predat ors, pathogens and parasi t e s, whereas th e l a t e r i n cl udes such t echni ques as st eri l e -m al e rel ease and genet i c m a ni pul at i ons.B i ol ogi cal control agent s are grouped i n t o th ree cat egori e s: predat ors, parasi t e s and pathogens. Predat ors i n cl ude both vert ebrat e s and i nvert ebrat e s and m a y at t ack bot h ad u lt an d im m a tu re stag es o f m o sq u ito es. Helm in th , protozoan and fungal parasites and m i crobial pathogens genera lly only invade im m a ture stages, though m o rtality

m a y n o t o ccu r u n til th e early ad u lt stag e. Parasitic water m ites are an ex cep tio n in th at th ey attach to certain ad u lts
as th ey em erge from th e pupal st age and apparent l y redu ce adul t survi vorshi p i f th ey are abundant (Lanci ani & B o y e t t 1980) In general , bi ol ogi cal control i s mu ch m o re feasi b l e i n m a nagi ng perm anent wat e r m o squi t o es th an tem porary water form s. Th ere are th ree b a sic strateg i es fo r u tilizin g all b i o l o g i cal co n tro l ag en ts: (1 ) in creasin g ex istin g n a tu ral

enemy popul at i ons by habi t a t al t e rat i on, (2) one-t i m e i n tr oduc t i on of sust ai nabl e exot i c agent s from other regi ons or habi t a t s , and (3) augm ent a t i on of natu ral or exot i c enemy popul at i ons by repeat edl y rel easi ng non-sust ai nabl e, l abreared (or fi el d col l ect ed) organi sm s. To dat e onl y th e fi rst , i n creasi ng fi sh habi t a t th rough OM W M , has been used in Massachusetts. Bti is som e tim es classified as a biologi cal control agent but i t s appl i cat i on t echni que and m ode of
act i on as a st om ach poi son m o re cl osel y resem b l e a pesticide than a biological control agent per se . Ba cillu s sphaeri cus m a y m o re cl osel y fi t th e m odel of repeat edl y rel easi ng non-sust ai nabl e l ab-reared organi sm s as th ere i s evi d ence t o suggest th at i t

recy cl es wi th i n th e envi ronm ent
. No other bi ol ogi cal control agent i s current l y avai l a bl e for general fi el d use, though experi m e nt s cont i nue wi th m a y di fferent organi sm s (see bel o w). There are i m por t a nt reasons why bi ocontrol i s not m o re wi del y used agai nst m o squi t o es. Fi rst , th e di fferences i n bi ol ogy of th e vari ous speci es of m o squi t o es m a ke i t unl i k el y th at any one control agent will operate across a wide range of speci es. Second, m o squito breeding is wide spread, m a king it difficult for a biological control agent to find, or be placed in, all breeding areas. Third, predators such as bats and purpl e m a rt i n s, m a y eat m o squi t o es but prefer t o eat other, l a rger i n sect s. Further, even when abundant , th ey do not dri v e m o squi t o popul at i ons bel o w l e vel s th at peopl e gene ral l y fi nd i n t o l e rabl e. Fi nal l y , th ere i s a hi gh cost associated with sustained releases of a biological control agent and there ar e not, at this tim e, control agents available that require a single, or a fe w, releases to becom e established. Because of the lim ited application of biological control to m o squito es in Massachusetts, the following d i scu ssio n will fo cu s p r im arily o n th e feasib ility o f co n tro l ag en ts cu rren tly b e in g stu d i ed fo r m o sq u ito co n tro l. An im p o r tan t p o i n t to m a k e reg a rd in g b i o l o g i cal co n tro l is th at th e m o sq u ito co n tro l h a v e lim ited research cap ab ilities. W h i l e conduct i ng fi el d eval uat i ons of new control t echni ques i s a desi rabl e pract i ce for any m o squi t o controlprogram , th e project s shoul d not be expect ed t o fi nd and bri ng forward bi ol ogi cal control agent s wi thout subst a nt i a l h e lp fro m research in stitu tio n s su ch as th e state u n i v e rsity. 2. Predators

a. Intr oduct i on In order for any predat or t o i ndependent l y be an effect i v e control agent , i t mu st m eet t w o i m port a nt criteria: (1) its size and abundance in rela tion to the target species mu st be su fficient for it to kill or consum e a high percent a ge of th e prey popul at i on wi th i n a rel a t i v el y s hort t i m e peri od, and (2) i t s feedi ng behavi or shoul d be selective toward the prey speci es when it is present but allo w it to utilize other food item s when the target species is absent . These cri t e ri a are rarel y m e t i n ful l

. Predat ors th at are suffi ci ent l y l a rge and/ or abundant t o have a m a jor i m pact , usual l y l ack feedi ng speci fi ci t y . C onversel y , those wi th feedi ng speci fi ci t y are usual l y l e ss abundant because their populations are re gulated by a m o re restricted food supply. Vertebrate pr edators of insects have a clear size advantage but invert ebrate predators tend to exist in mu ch greater num bers. Because of the lim itations of predators as biocontrol agents, it is norm a lly essential to continuously raise and release the predator to achieve field densities high enough to cause real reductions in the prey species. However, i n som e cases, m a ni pul at i on of th e envi ronm en t t o th e advant age of natu ral predat or popul at i ons can provi de an adequat e augm ent a t i on effect

. b. Vertebrate predators Fish Larvi vorous fi sh are th e ol dest and perhaps m o st effect i v e tr adi t i onal bi ol ogi cal control agent used agai nst

m o squi t o es. In cert a i n habi t a t s th ey m a y , by th em sel v es, provi de adequat e l a rval control th roughout th e breedi ng season. If not , pest i c i d es such as B T I or m e thoprene whi c h are non-t oxi c t o vert ebrat e s can be used i n an i n t e grat ed fash io n with fish

. As al ready m e nt i oned, th e m a i n reason open sal t m arsh m a nagem e nt strat e gi es effect i v el y control m a ny saltm arsh Aedes in the Northeast is because this m e thod provi des access for the abundant estuarine populations of larv iv o r o u s k illifish ( Fundul us spp.) i n t o th e m o squi t o breedi ng pool s i n th e hi gh sal t m arsh (Hruby & M ont gom ery 1986). Th e m o sq u ito fish Ga mb u s ia a ffin is i s di stri but ed wi del y th roughout th e warm er part s of th e worl d and i s th e speci es m o st oft e n reared and i n tr oduced i n t o fresh wat e r habi t a t s for m o squi t o control

. The bi ol ogy and use ofth i s fi sh i n m o squi t o control was revi ewed by M e i s ch (1985). It i s an opportuni st i c feeder and avi d l y eat s pupae and l a t e -i nst a r l a rvae of cul i c i n es and chi r onom i d s. It i s m o st effect i v e agai nst Cu lex i n unveget a t e d, perm anent ponds but has been wi del y used i n C a l i f orni a and th e Gul f St at es agai nst ri cefi e l d Aedes and Psorophora

. Because Gambusia is so aggressive and fecund, it m a y repl ace im portant com m e rcial or rare native fish speci es. Thi s has rai s ed envi ronm ent a l concern over th e i n tr oduct i on of th i s fi sh i n t o natu ral wat e rs where i t does not already occur. A recent article by Rupp (1996) has renewed this debate, both em phasizing real successes and real concerns over Gambusia use (see “C om m e nt s on ‘adverse Assessm ent s of Ga mb u s ia a ffin is ’” (JAM C A 1996) and Boklund 1997, Eliason 1997, a nd Rupp 1997). Because it is not a native sp ecies of Massachusetts it m a y not be im ported and released in state waters. Out s i d e of th e m o squi t o fi sh, th e com m on guppy ( Po ecilia reticu l a t a ) has received the m o st attention for

m o squi t o control (B ay 1985). C o m p arat i v e studi es i ndi cat e th at i t

i s a l e ss effect i v e predat or th an Gam busi abut i t i s m o re t o l e rant of pol l u t e d wat e rs. M a ny other nat i v e fi sh have been expl ored for th ei r m o squi t o control pot ent i a l (B ay 1985). Studi es i n North Afri ca (Al l o et al . 1985) suggest th at m a l a ri a m a y be control l e d th rough th e annual i n tr oduct i on of nat i v e fi sh from stream s i n t o th e m a nm ade wat e r st orage t a nks whi c h produce th e vect or Anophel e s in th is reg i o n . Bird s M a ny bi rds depend on i n sect s as food and those whi c h captu re i n sect s on th e wi ng (e.g., th e swal l o ws), have been credi t e d wi th consum pt i on of si gni fi cant num bers o f m o sq u ito es. Pu rp le m a rtin s sp ecifically h a v e b een prom ot ed on th e basi s of th e cl ai m th at th ey oft e n consum e 10-12 thousand m o squi t o es per day but Kal e (1968) concl uded on th e basi s of exi s t i ng evi d ence th at al l cl ai m s of m a rt i n s si gni fi cant l y reduci ng m o squi t o popul at i ons were unsubstantiated and, because of se veral biological facts, were unlikely to ever be dem onstrated. The facts on which these conclusions were drawn are as follows: (1 ) Mo sq u ito es were a n e g lig ib le item in th e d i et o f m a rtin s in th e o n l y two p u b lish e d stu d i es in which the contents of m a r tin gizzards were exam ined. (2) None of the published statem ents appear ing in the popular ornit hological literature which attrib u t es a m o sq u ito -eatin g h ab it to m a rtin s is b a sed o n factu a l stu d y o rscien tific referen ce. In fact , th ere i s evi d ence th at m a rt i n s feed m o re on l a rger i n sect s i n cl udi ng speci es of dragonfl i e s whi c h m a y be predat ors of adul t m o squi t o es.(3) B e havi or pat t e rns of m o squi t o es and m a rt i n s are such th at th ey t e nd t o not fl y at th e sam e hei ght or at the sam e tim e. Thus, contact between the two is m i nim a l. (4) There i s no evi d ence th at any avi a n speci es can effect i v el y control a pest i n sect upon whi c h i t feeds when th e i n sect i s at or near peak abundance.Other Vertebrates Mosquito control by insectivorous bats was tried in the early part of this centu ry but without success (Kale 1968, Storer 1926). Bats continue to appear in the popul ar press as legitim ate m o s quito-control agents (W right 1996) but are not consi d ered worthwhi l e agent s i n C o m m on-sense Pest C ontrol (Ol kowski et al . 1991), whi c h i s very thorough i n i t s coverage of non-chem i cal control op t i ons, or i n m a i n stream m o squi t o control (M i t c hel l 1992).

c. Invertebrate predators Predat ors of m o squi t o eggs. Evi d ence exi s t s of predat i on on di apausi ng fl ood wat e r m o squi t o eggs by m i t e s and beet l e s, and on Cu lex egg rafts by fish (Collins & W a shino 1985). Nonetheless, egg predation appears to be a relatively m i nor com ponent

o f

n a tu ral m o sq u ito m o rtality an d is n o t b e in g stu d i ed fo r b i o l o g i cal co n tro l. Terrestrial insect and spider predat ors of m o squi t o adul t s Predat i on on em ergi ng and i ndoor rest i ng adul t m o squi t o es has been readi l y observed but th e i m pact of th i s

m o rtality on populations is extrem ely diffi cult to assess. Certain spiders (especi ally Tetragnatha) and predatory flies (m ai nl y Em pi di dae, Anthomy i i d ae and Dol i c hopodi dae) have been shown by preci pi t a t i on t e st s t o have consum ed

em erging m o squitoes (Collins & W a shino 1985). In one Br itish study, up to 28% of the spiders tested had eaten

m o squi t o es (Servi ce 1973). C e rt ai n adul t dragonfl i e s report e dl y captu re m o squi t o es on th e wi ng but th ese observat i ons have not been backed up by any control l e d fi el d studi es. Sy nanthropi c em esi n e bugs (R eduvi i d ae) appears t o be pot ent i a l l y i m port a nt predat ors of i ndoor rest i ng m o squi t o es i n th e tr opi cs. In sum , th e prospect for enhanci ng or m a nagi ng i nvert ebrat e predat ors for m o re eff ectiv e ad u lt co n tro l is n o t en couraging, especially in
tem p erate regions. Aquat i c i n sect predat ors of m o squi t o l a rvae & pupae Aquat i c i n sect predat ors sel dom occur i n si gni fi cant num bers i n th e t e m porary fl oodwat ers th at produce

m o st pest m o squitoes. Studies of predation have therefore largely ta ken place in perm anent ponds or sem i

perm anent habitats such as rice fields, rock pools or ve rnal woodland pools. The adu lt stage of m o st predaceous aquat i c beet l e s and tr ue bugs can fl y (usual l y at ni ght ) so natu ral col oni zat i on of newl y fl ooded habi t a t s can occur i n

a m a tter o f d a ys. Dev e lo p m en t tim e fo r th ese in sects is u s u a lly fro m sev e ral week s to sev e ral m o n th s . Am ong the beetles, the dytiscids (predaceous divi ng beetle), which are predaceous both as larvae and adults, are the m o st effective predator s of m o squitoes. There is evidence fro m studies in rice fields that adultd y tiscid s selectiv ely lo cate an d co lo n i ze sites with lo cally h i g h co n cen tratio n s o f m o sq u ito larv ae (Co llin s & W a shi no 1985). M a ss product i on m e thods for dy t i s ci ds have ne ver been devel oped. W h i r l i g i g beet l e s (Gy r i n i d ae) only feed at the surface where they m a y prey on concentrations of em ergi ng adult m o squitoes. Hydrophilids are onl y predaceous as l a rvae and seem t o feed m a i n l y on chi r onom i d m i dges. Only two aquatic fam ilies of true bugs, the back swim m e r (Notonectidae) and pigmy back swim m e r (Pleidae) have received serious consider ation as m o squito control agents. Pleids are generally not abundant enough
t o have si gni fi cant i m pact but not onect i d s can becom e qui t e dense i n cert a i n habi t a t s . M a ss reari ng of th e l a t t e r appears t o be possi bl e. W a t e r boat m en (Corixidae) are also com m on and si m ilar in appearance to backswim m e rs but th ey are m o st l y detr i tu s feeders. Other predaceous a quat i c Hem i pt era th at have been suggest ed as m o squi t o p r ed ato r s b u t wh ich n o r m a lly o ccu r in in su fficien t d e n s ities to h a v e mu ch v a lu e as n a tu ral co n tro l ag en ts in clu d e th e gi ant wat e r bugs (B el ost o m a t i d ae), wat e r scorpi ons (Nepi d ae), wat e r m easuri ng bugs (Hy d rom e tr i d ae) and th e t w o fam ily o f su rface-feed in g , water strid e rs (Gerrid ae an d Veliid ae). Dragonfl y nai a ds have been m a rket ed com m e rci a l l y for m o squi t o control and at l east one t o wn i n M a ssachuset t s , and others i n New Ham p shi r e and M a i n e, have purchased dragonfl i e s for m o squi t o control

. In northern clim ates these insects require 1-5 years to m a tu re, so th ey n o r m a lly o ccu r in p e rm an en t waters o n l y. Furtherm ore, m a ny are bottom feeders that seldom if ever com e in contact with m o squito species that feed at the surface or in the water colum n . Most bottom -feeding m o squitoes (i.e. Aedes ) occur i n t e m porary wat e r cont ai ni ng few i f any dragonfl y nai a ds. Another fact or wei ghi ng ag ai nst th e m o squi t o control effi ci ency of th ese aquat i c p r ed ato r s is th e fact th at th ey n o r m a lly o ccu r at lo w d e n s ities. Ad u lts o f m a n y sp ecies are territo rial an d th is seem s to spatially lim it population densities of naiads as well as adu lts. In certain habitats such as rice fields, naiads m a y becom e quite abundant but populations fluctuate greatly and their role in lim iti ng populations of rice field

m o squi t o es i s l i m i t e d at best . No control l e d, fi el d studi es have been done i n whi c h na i a ds have perform ed wel l as bi ol ogi cal control agent s . The tr i c hopt eran Li mnephi l u s i ndi vi sus m a y be an i m port a nt predat or of earl y spri ng Aedes i n woodl and

swam ps in Ontario but m o st caddisflie s are om nivorous shredders rather th an predators (Collins & W a shino 1985, Merritt & Cum m i ns 1985). Prospects for m a ss rearing and m a ni pulating caddisfly larvae are not very bright. Many of the aquatic nem a toceran relatives of m o squitoes cont ain groups with predaceous larvae. These include the fam ilies Chaoboridae, Chirom om idae, Ce ratopogonidae, Tipulidae, Anthomyiidae, and others. Most are too sm allto co n s u m e m a n y m o sq u ito larv ae. Pred atio n o n sm all, early in stars o ccu rs b u t it is far less efficien t in red u c in g th e

num bers of adul t s th an i s predat i on on l a t e i n st ars and pupae. Mochlonyx (C haobori d ) predat i on on spri ng Ae. communi s popul at i ons has been observed i n woodl and pool s i n M a ssachuset t s (Edm ans, personal com muni cat i on) and i n Europe (C hodorowski 1968). The i m pact of th i s sm al l but voraci ous predat or i s unknown. The i n sect predat or wi th th e m o st prom i s e i n m o squi t o control i s another m o squi t o . Larvae of th e nonbi t i ng genus Toxorhychites are l a rge and effect i v e predat ors of m o squi t o es th at devel op i n natu ral and m a n-m a de
cont ai ners such as t i r es, tr ee hol es, m e t a l cans, and l eaf axi s (St e ffan & Evenhui s 1981). Unfortunat e l y , none of th e 7 0 so m e sp ecies in th is m a in ly tro p i cal g e n u s can su rv iv e th e winters as far north as Massachusetts. Their use here woul d th erefore requi re repeat ed, annual rel eases of l ab-rear ed fem a l e s. Thi s i s not warrant ed at th e present t i m e si nce cont ai ner-breedi ng speci es general l y do not represent th e m a jor nui sance or heal th th reat in Massach u s etts. Thi s si tu at i on coul d change i f Ae. al bopi ct us becom e s wel l est abl i s hed i n used t i r es i n th e Northeast

. Focks (1985)
st at es th at al though i t i s possi bl e t o control or reduce cert a i n speci es of cont ai ner-breedi ng m o squi t o es wi th i nocul at i v e or i nundat i v e rel eases of Toxorhynchites , th e useful ness of th i s genus i n pract i cal , operat i onal control program s has y e t t o be dem onstr at ed. Other i nvert ebrat e predat ors of l a rvae and pupae. Am ong th e non-i n sect predat ors of th e i m m a tu re st ages of m o squi t o es, onl y hy dra (C ni dari a: Hy drozoa), fl at worm s (Pl a t y hel m i n th es: Turbel l a ri a) and copopods (C y c l opoi da) have been studi ed i n any det a i l

. B o th hy dra and fl at worm s can be easi l y m a ss produced and, unlike m o st predaceous insects, they can be

m a intained at high densities without cannibalism

. In the la boratory, they kill far m o re larvae than they consum e. B o th groups produce sem i -dorm a nt eggs so th ey occur na tu ral l y i n shal l o w t e m porary pool s as wel l as perm anent

swam ps and ponds. Detrim ental effects on young fish have been reported when these predators are at high densities (M ul l a& Tsai 1978). Both of these predators have good potential as contro l agents in the Northeas t but additional long-term fi el d eval uat i ons are needed. As wi th m o squi t o fi sh, th e l aborat ory product i on, st orage, and fi el d tr ansl ocat i on of
th ese organi sm s requi res a cert a i n degree of sophi st i cat i on, whi c h i s usual l y l acki ng at th e l o cal l e vel

. C u rrent l y , th ere are n o co m m e rcial so u r ces fo r th e q u a n tities th at wo u l d b e req u i red fo r m o sq u ito co n tro l ap p licatio n s . Natural populations of predaceous cyclopoid copepods appear to limit the distribution of container breedi ng m o squi t o es i n cert a i n tr opi cal set t i ngs (M art e n 1984). However, th ey have never been shown t o bei m port a nt predat ors i n t e m p erat e regi ons or i n other t y pes of aquat i c habi t a t s . Therefore th ei r pot ent i a l for th e bi ol ogi cal control of pest and vect or m o squi t o es i n M a ssachuset t s appears t o be ni l

. 3. Parasi t e s and Pat hogens

a. m e rm ith id n e m a to d e p a rasites Outside of bacteria, parasitic nem a todes are the onl y natural parasites and pathogens that have ever achieved operational status in m o squito control. Known parasitic roundwor m s of m o squitoes now num ber over 20 sp ecies. Th e free-liv in g , aq u a tic, p r ep arasitic stag e wh ich h a tch e s fro m th e n e m a to d e eg g , seek s o u t an d p e n e trates th e cu ticle o f h o s t m o sq u ito larv ae. Larv ae are u s u a lly k illed in th e last in star. In a few sp ecies, th e m a tu re wo rm s are carried over in the adult m o squito and cause m o rt ality when they exit during attem p ted pseudo-oviposition. Romanomermi s cul i c i v orax (i ncl udi ng m o st references t o Reesimermis nfelseni ) is the species that has been m o st ext e nsi v el y studi ed. M e thodol ogi es for th e m a ss product i on and com m e rci a l preparat i on of th i s speci es have been devel oped and i t was bri e fl y m a rket ed as Skeet er Doom i n th e l a t e 1970' g. Low sal e s and probl em s wi th
th e shi ppi ng and shel f-l i f e of vi abl e eggs appear t o have been th e m a jor fact ors whi c h l e d t o th e m a rket i ng fai l u re of
th i s agent (Servi ce 1983). Other econom i c drawbacks i n cl ude host speci fi ci t y whi c h l i m i t s i t s effect i v eness t o onl y certain sp ecies (e.g ., it is in effectiv e in co ld , p o llu ted o rb r ack ish water), an d th e lack o f p a ten t p r o t ectio n fo r

com p anies investing in the production and m a rketing of this product. In add ition, applicators need som e special sk ill an d train i n g to effectiv ely u s e th is b i o c o n tro l ag en t. Th e ten d e n c y o f th is ag en t to n a tu rally recycle o n ce it is i n tr oduced i n t o favorabl e aquat i c habi t a t s i s benefi ci al from a control vi ewpoi nt , but i t

further reduces th e l ong-t e rm

m a rketability and profit potential for pr ivate producers. It rem a ins under study, however, as a recent article ( M i jares et al . 1997) di scussed th e est abl i s hm ent of R. cu licivo r ax in sewage settling ponds and natural ponds in C uba. On th e bi ol ogi cal pl us si de, m e rm i th i d s appear t o be hi ghl y com p at i b l e wi th a wi de range of chem i cal pest i c i d es and growth regul at ors. M o reover, th ey : 1) are non-speci fi c and wel l sui t e d t o th e l i f e cy cl e of th ei r

m o squito host, 2) produce high levels of infection and m o rtality, 3) can be easily m a ss-produced and applied with
st andard spray equi pm ent , and 4) offer no th reat t o non-t a rget organi sm s or th e envi ronm ent
. There are speci es of m e rm i th i d s whi c h appear t o be hi ghl y speci fi c t o spri ng snow-pool Aedes and t o saltm arsh Ae. so llicita n s (Pet ersen 1985). However, th ese worm s have not been est abl i s hed and studi ed i n th el aborat ory . Such speci es m a y have great er control pot ent i a l in n o r th ern co astal states lik e Massach u s etts th an th e

m o re tro p i cally ad ap ted R. cu licivo r ax . Si nce th e t echnol ogy for usi ng m e rm i th i d s i n m o squi t o control al ready exi s t s , and th ere are num erous fi el d trials d o c u m en tin g th eir co n tro l p o t en tial, th e fu tu re av ailab ility an d u s e o f th ese b i o c o n tro l ag en ts in o p e ratio n a l program s seem s t o depend on changi ng econom i c and m a rket forces (Pet ersen 1985). b. M i crospori d i a Vi rtual l y al l m o squi t o speci es careful l y exam i n ed ha ve been found t o harbor th ese parasi t e s. Larvae are i n fect ed by i ngest i ng th e spore st age. Spores, whi c h are produced at th e end of th e l i f e cy cl e, have oft e n proven di ffi cul t t o i nduce and t o rei n fect l a rvae i n l ab cul tu res. Few m i crospori d i a n l i f e cy cl es are wel l enough known t o assess bi ocontrol pot ent i a l

. Li fe cy cl es vary from si m p l e t o com p l e x and oft e n form th e basi s for th e non-t a xonom i c groupi ng of th ese prot ozoan parasi t e s. The si m p l e st form s (Ty p e I) occur m a i n l y i n t e rrestri al i n sect s and even th e one aquat i c speci es known from m o squi t o es ( N o sema algerae ), d o e s n o t cau se m o rtality u n til, th e ad u lt stag e. Fo r th is reaso n N

. algerae has l i m i t e d pot ent i a l for reduci ng pest probl em s but m a y i m pact on di sease tr ansm i ssi on by reducing survival and fecundity. W ild strains only persist in larval popula tions for short periods and cause little d i rect m o rtality. Typ e II m i cro s p o r id ia h a v e sim p le, asex u al life cycles sim ilar to Typ e I fo rm s an d th ey also sh o w little prom ise in m o squito control (Hazard 1985). Type III form s are dim o rphic, have binucleate spores, and kill

m o sq u ito es in th e larv al st age. Only one species ( Ha za rd ia milleeri ) i s known from m o squi t o es and i t seem s t o have low infectivity (Hazard 1985). Type IV m i crosporidia include m a ny species from m o squitoes and have the

m o st co n tro l p o t en tial. In fected larv ae are u s u a lly k illed b u t a few fem a les su rv iv e an d carry th e in fectio n v i a th e ovary to the next generation. However, transovarial infection ceases af ter a single generation. Non-ovarian m odes of transm ission mu st exist but this i ssue along with the possibility of sexual reproduction and alternate hosts are as y e t unresol ved. Addi t i onal basi c research i s requi red befo re any m i crospori d i a n can be consi d ered i n th e bi ocontrol of m o squitoes (Hazard 1985). Tet r ahymena and Lambornel l a (tetrah y m e n i d ciliates) Th e lack o f a resistan t restin g stag e an d d i fficu lty in cu ltu rin g th ese ciliated p r o t o z o ah a s p r ev en ted th e thorough study and eval uat i on of th i s group of pot ent i a l bi ocontrol agent s . Ongoi ng studi es of Lambornel l a cl arki in Califo r n i a treeh o l e Ae. sierrensis shoul d hel p t o bet t e r assess th e control val u e of th ese parasi t e s i n th e near futu re (Anderson et al . 1986).Helico s p o r id iu m

There is still debate concerning the proper classifica tion of this spore-form ing group of parasites; som e believe they are prim itive Ascomy cetes f ungi. There are only 3 reports of natura l infections in m o squitoes. They appear t o i n fect a wi de range of speci es but al so m a y i n fect non-t a rget i n sect s as wel l

. Hi gh dosages of spores are requi red t o i n fect ol der i n st ars i n th e l ab. C ont i nuous cul tu res of th ese parasi t e s do not exi s t so th e basi c research needed t o eval uat e th ei r bi ocontrol pot ent i a l i s not forthcom i ng.

c. Fungal Pathogens Coelomomyces M a ny form s of pathogeni c fungi have been known from both l a rval and adul t st ages of m o squi t o es si nce the 1930' s. However, it was not until the discovery of th e obligate alternate host (i.e ., m i crocrustacea) in the m i d70’s th at cul tu res and ful l

- scal e l aborat ory i nvest i g at i ons were possi bl e wi th Coelomomyces (W hi sl er et al . 1974, 1975). The rather com p lex life cycles of som e species have recently been describe d and m e thods for in vivo

cu ltu rin g estab lish e d

. Befo re wid e -scale field ap p licatio n can o ccu r, m a ss in v itro cu ltiv atio n o f th e in fectiv e bi fl agel l a t e zy got e st age needs t o be devel oped. If Coelomomyces , and perhaps th ei r copepod and ostr acod in term ed iate h o s ts, are in tro d u ced in to fav o r ab le h ab itats, th e p o t en tial fo r n a tu ral recyclin g ex ists. Ho wev e r, to o little is known about the host ranges a nd habitat requirem e nt of m o st Coelomomyces to recom m e nd any such i n tr oduct i on at th e present t i m e. M o reover, speci es of Coelomomyces do not rout i n el y provi de hi gh and predi c t abl e lev e ls o f m o sq u ito co n tro l. It is, p r em atu r e to critically assess th eir p o t en tial as co n tro l ag en ts to b e u s ed i ndependent l y or as part of an i n t e grat ed control program (Federi c i et al . 1985). Studi es rel a t e d t o th ei r eval uat i on as operational control agents have only recently been initiated and it is not likely that any Coelomomyces will b e

o p e ratio n a l with in th e n ear fu tu re.Lageni di um gi gant eum . Th is m o sq u ito -sp ecific water m o ld is a v e ry p r o m isin g b i o l o g i cal co n tro l ag en t, esp ecially in fresh water and in warm er clim ates. This fungal pathogen can be m a ss produced on artificial m e dia and can recycle in as little as 3 hours (M cC ray 1985). It has a resi st ant , dorm a nt st age and i n fect s a wi de range of m o squi t o speci es. Un fo rtu n a tely, it is n o t effectiv e in p o llu ted , b r ack ish o rco lt waters. Th is lim its its co m m e rcial v a lu e an d it pot ent i a l useful ness i n north ern and coast a l st at es l i k e M a ssachuset t s (Servi ce 1983). Other Fungi Fungi are am ong th e com m onest pathogens of i n sect s and m a ny other genera besi des Coelomomyces and Lageni di um have been report e d from m o squi t o es. Of th ese, Culicinomyces and Met arhi zi um have received the m o st at t e nt i on. B o th groups i n fect a wi de range of m o squi t o speci es but rel a t i v el y hi gh concentr at i ons are requi red t o cause i n fect i on. They can t o l e rat e organi c pol l u t i on and sal i n i t y but not hi gh t e m p eratures (i .e. above 30 ° C). These fungi can be grown on i n expensi v e art i f i c i a l m e di a but no resi st ant rest i ng st age has been fount . Di ffi cul t y i n achi e vi ng l ong t e rm st orage of i n fect i v e st ages and formul at i on probl em s rem a i n as barri ers t o com m e rci a l product i on. Noneth el ess, th ese fungi are a prom i s i ng group of bi ocontrol agent s whi c h m a y provi de new m o squi t o

co n tro l to o l s in th e fu tu re. Eryni a aquat i c a Eryni a aquat i c a i s an Ent o m ophthoral es fungus, and i s th e onl y speci es of th e genus known t o i n fect th e im m a tu re aq u a tic stag es o f m o sq u ito es . It was fi rst di scovered i n fect i ng Ae. canadensi s and Cs. moristans larv ae in woodl and pool s i n Hart ford C ount y , C onnect i c ut from l a t e M a y t o earl y June (Anderson & R i ngo 1969). It has since been recovered in early May from Ae. st i m ul ans in woodland pools near the villa ge of Cam b ridge, New York (M ol l o y & W r ai ght 1982) and from Ae. cant at or on M a y 21, 1981 i n a shal l o w sal t m eadow pool i n M i l f ord, Connecticut (Andreadis & Magnarelli 1983). Most recen tly, is was discovered in 1995 and 1996 in a woodland pool i n B r i s t o l , R hode Isl a nd (C hri s t i e 1997). St ei nkraus and Kram er (1989) col l ect ed Ae. fitch ii larvae infected with E. aquat i c a f r o m as e mi

- p e r ma n e n t woodland pool in Tom pkins C ounty, New York. They used infected pup ae to successfully tran sm it the disease to

em ergi ng adul t Ae. aegypt i , on whi c h rest i ng spores of th e fungus devel oped. Eryni a aquat i c a h a s ch aracteristics wh ich m a k e it attractiv e as a m i crobial agent: it is capable of causing epi z oot i c s, has been found i n both freshwat e r and bracki s h wa t e r m o squi t o es and has a rest i ng spore st age th at m a ysurvi v e wel l i n st orage. Operat i ng agai nst i t

i s th e fact th at i t

has onl y been found i n cool er, spri ngt i m e wat e rs. One thought is that infected pupae m a y be rem oved from the origin al infestation site and placedin other, nearby pools. A fungus that kills in the pupal st age works against its own spread. d. B act eri a l pathogens Ba cillu s th u r in g i en sis var. israelensis B t i Serot y pe H-14 has becom e an i m port a nt bi ol ogi cal larv icid e fo llo win g its d i sco v e ry in th e Neg e v d e sert i n 1976. W i th i n th e l a st 5 y ears i t has becom e wi del y used by th e m o squi t o control project s i n M a ssachuset t s . It i s now the larvicide of choice in m a ny s ituations because of its host specific ity, high and rapid m o rtality to m a ny

m o squi t o es speci es, and i t s envi ronm ent a l safet y . It i s qui t e di st i n ct from th e B t strai n s whi c h i n fect l e pi dopt erous in sects. Its track reco rd in co n tro llin g p o llu ted

- water Cu lex is m i xed, apparently because it sinks to the bottom and
th e act i v e m o i e t y rapi dl y bi nds t o organi c part i c ul at es. C onsequent l y , hi gher dosages are requi red t o achi e ve good
control i n hi ghl y organi c and deep-wat er si tu at i on. Sal t m ar sh m o squi t o es general l y requi re rat e s at th e hi gh end of
th e l abel e d appl i cat i on rat e s for effect control

. Li qui d, powder, granul ar and sl ow-rel ease bri quet formul at i ons are

co m m e rcially av ailab l e. Bti mu st be ingested to cause toxicity to filter-feeding m o squito larv ae; pathology occurs in cells of the

m i dgut wall. It is least toxic to 4th instars since they cease feeding at least 12 hours prior to pupation. The

m o squi t o t oxi c i ngredi e nt of B t i preparat i ons i s th e heat l abi l e del t aent o t oxi n l o cat ed i n th e prot ei naceous parasporal crystallin e in clu s io n s syn th e sized co n c o m itan tly with th e sp o r e d u r in g sp o r o g e n e sis. On ce released in th e envi ronm ent , i t bi odegrades rapi dl y (i t i s usual l y onl y act i v e 1-3 day s ) and th i s bact eri u m (gram negat i v e Bacillaceae) does not recycle. This is considered the only m a jor drawback of this highly effective m o squito pathogen but it has enhanced its co m m e rcialization (Lacey & Undeen 1986). Th e b i o c id al activ ity o f Bti to x i n ap p ears to b e lim ited to larv ae o f certain fam ilies o f n e m a to cero u s Di pt era. A l a rge num ber of l aborat ory and fi el d t e st s have confi r m e d th at al l non-nem a t o cerous, non-t a rget organi sm s are vi rtual l y unaffect ed (Lacy 1985). Al l exi s t i ng dat ai ndi cat e th at th e unal t e red prot oxi n of B t i i s al so safe to vertebrates including hum ans (Lacey 1985). Further im provem e nts in the efficacy and price com p etitiveness of th i s control agent , brought about by formul at i on changes and genet i c engi neeri ng, are l i k el y t o occur i n th e near fu tu re. In ad d itio n , fo rmu l atio n o f th is ag en t with o th e r co m p atib le an d p e rh ap s syn e rg istic ag en ts su ch as j u v e n ile horm one anal ogs (e.g. Al t o si d) i s current l y underway . Su ch m i xture have t w o i m port a nt advant ages. They reduceth e l i k el i hood of m o squi t o es devel opi ng resi st ance t o ei th er agent and, secondl y , th ey wi den th e wi ndow for control since Bti is m o st effective agai nst earl y i n st ars and growth regul at ors agai nst l a t e r i n st ars. Bacillus sphaericus

. Although only recently available, B. sphaeri cus m a y have greater control poten tial than Bti because of its ability to continue to recycle once it is in troduced. It has m a ny of the sam e benefi cial attributes of Bti but all strains isolated to date are less effective against a wide range of sp ecies th an is Bti. At th e m o m e n t it is p r im arily m a rk eted against Culex i n hi gh-organi c wat e rs but research i s on-goi ng i n expandi ng i t s control pot ent i a l

.
e. Vi ral Pathogens The bi ol ogi cal control pot ent i a l of both non-accluted (i ri dovi ruses and densonucl e osi s vi ruses) and occl udet (bacul ovi ruses, cy t opl asm i c pol y h edrosi s vi ruses and ent o m opox vi ruses) vi ruses pathogeni c t o

m o squitoes has recently been reviewed by Federicci (1985). It is sufficient here to sim p ly paraphrase from the

sum m a ry of th i s thorough revi ew as fol l o ws: Anal y s i s of research conduct e d t o dat e m a kes i t cl ear th at none of th e vi ral pathogens of m o squi t o es can current l y be consi d ered good candi dat e s for m o squi t o m a nagem e nt program s. The t w o m a i n reasons for th i s

assessm en t are th at v i ru ses d i sco v e red so far p o ssess lo w in fectiv ity fo r o r ig in al o raltern ate h o s ts an d th ere is n o readi l y avai l abl e m e thod for m a ss product i on of vi ri ons. Thi s apparent l ack of control pot ent i a l i s m o st obvi ous when one consi d ers th at few fi el d tr ai l s have been conduct e d wi th th ese agent s even though th e fi rst one was d i sco v e red o v e r 1 5 years ag o . W h ile it ap p ears u n lik ely th at v i ru ses will b e d e v e lo p e d fo r m o sq u ito co n tro l in th e near future, they m a y prove to be ex trem ely useful m i crobial agents in th e long term , perhaps in 2 or 3 decades, once we l earn how t o m a ni pul at e th em effect i v el y . B i ot echnol ogy has th e great est pot ent i a l for engi neeri ng new

m o re useful biocontrol organism s am ong the viruses because of thei r sim p le m o lecular structure. 4. Pest Speci es M a ni pul at i on A som e what di fferent approach t o bi ol ogi cal control i s m a ni pul at i on of th e m o squi t o genom e t o ei th er 1) i nduce reproduct i v e fai l u re (l eadi ng t o popul at i on el i m i n at i on) or 2) bri ng about perm anent changes i n th e behavi or or phy si ol ogy of th e t a rget popul at i on so i t no l onger vect ors di sease or bi t e s peopl e. There are num erous theoretical m echanism s by which this could be accom p lished. Following is a brief discussion of the three approaches that have been m o st com m onl y di scussed and researched.

a. Sterile Insect TechniqueThe early and continuing success of the sterile m a le release p r o g r am in elim in atin g th e screwwo rm fly from th e U.S. and M e xi co has gi ven ri se t o m a ny i nve st i g at i ons and new i d eas for control l i ng other i n sect s (i nocul at i ng m o squi t o es) th rough th e use of th i s or som e other genet i c t echni que. Except for frui t fl i e s, th i s m e thod has not y e t been successful l y appl i e d t o other i n sect s i n operat i onal program s and th e t echni que i s not current l y bei ng pursued for m o squi t o control

. b

. In co m p atib ility In co m p atib ility resu ltin g fro m a lack o f fertility in sex u a l u n i o n s m a y o ccu r d u e to a v a riety o f g e n o m ic failures or due to the effort of bact eria-like sym b ionts to control the repr oduction of host (Barr 1985). The feasibility of suppressi ng Cu lex pi pi ens through cytoplasm i c incom p atibility was de m onstrated in a Burm ese Village over 20 years ago (Laven 1967) but the practicality of this m e t hod has not been confirm e d by any other field tests. Mo reo v e r, in co m p atib ility facto r s h a v e b een iso l ated in o n l y a few m o sq u ito sp ecies to d a te.

c. Chrom o som a l Aberrations There are several heritable chrom o som e rearrangem e nts th at can, in theory, be used to in j ect g e n e tic lo ad i n t o a m o squi t o popul at i on and/ or t o effect a perm anen t change i n th e genet i c m a keup of th e popul at i on. These aberrations can be used to 1) increase genetic lethal load (serility is lim ited to 50-80% because of the low chrom o som e num ber (three, in m o st m o squitoes) or 2) re place noxious species with harm less strains if appropriate vi abl e hom ozy gous rearrangem e nt s are avai l abl e. The l a t t e r i s perhaps onl y appl i cabl e i n th e case of i m port a nt di sease vect ors. Natu ral l y occurri ng aberrat i ons can be screened for i n wi l d popul at i ons but th ei r frequency i s great l y i n creased th rough exposure t o mu t a gens. C ontrol l i ng m o squi t o es th rough th e use of chrom o som a l aberrat i ons requi res a m a jor basi c research effort and a target species that is easily colonized. This later req u i rem e n t au to m a tically elim in ates m a n y im p o r tan t sp ecies from consi d erat i on.d. Com p etitive Displacem ent The fi nal , and som e what abstract , strat e gy for control l i ng m o squi t o es bi ol ogi cal l y i s th e ecol ogi cal l y based notion of displacing a noxious species by introducing a beni gn but m o re com p etitive (i.e. better adapted) exotic one. Thi s i d ea has been suggest ed pri m ari l y t o control cont ai ner-breedi ng speci es l i k e Ae. aegypt i . However, beni gn m o squi t o speci es are di ffi cul t t o fi nd, as m o st m o squi t o es th at have becom e est abl i s hed ( Ae. aegypt i , Ae. al bopi ct us ) are as bad or worse than the species w ith wh ich th ey co m p et e (cont ai ner-breedi ng Cu lex and Ae. triseria tu s ). 5. Other C ontrol Approaches

a. Trap out t echni ques. Al l experi ence t o dat e i ndi cat es th at whi l e vari ous tr aps m a y be good sam p l i ng devi ces for adul t m o squi t o es, th ey are t oo i n e ffi ci ent and l i m i t e d i n th ei r range t o provi de any benefi t i n reduci ng bi t i ng annoy ances (Nasci et al . 1983). W o rk i s ongoi ng on at tr act ant s (oct anol ) th at woul d both great l y i n crease tr ap col l ect i ons of m o squi t o es and reduce non-t a rget s tr apped, but no product s are m a rket ed for th i s purpose t o dat e . Electrocutor traps (“Bug Zappers”) continue to be a popular item , with an estim ated 1.75 m illion sold in the United States each year (Mitchell 1992) but they are extrem ely non-specifi c (m osquitoes generally m a ke up less
th an 5% of th e cat ch, and m a y be harm ful t o other i n s ect speci es. They cannot be consi d ered a part of any

m o squi t o -control program . b. R e pel l e nt s. Personal prot ect i on th rough th e use of m o squi t o repel l e nt s i s an appropri a t e al t e rnat i v e t o control l i ng th e m o squi t o popul at i ons before th ey bi t e . Thi s i s especi al l y tr ue i f th e peri ods of annoy ance are i n frequent and bri e f and where th e l a nd areas are t oo vast and unpopul at ed t o econom i cal l y consi d er control program s. The m o st com m only used m o squito repellent is DEET (N,N)(diethyl-m etatoluam i de) which has been formul at ed and sol d under a vari et y of tr ade nam e s (e.g., Off, M u skol , C u t t e rs), i n a vari et y of concentr at i ons and as both aerosol spray s (usual l y ca 15%) and l o t i ons (up t o 100%). Laborat ory t e st s have shown th at m a xi mu m repel l e nt durat i on (ca. 1-2 hours) i s obt ai ned wi th a concen tr at i on of ca. 50% so th at hi gher concentr at i ons do not provide appreciable advantages. The m a jor disadvantage o£ DEET are: 1) rel a t i v el y short prot ect i on t i m e 2) som e what offensi v e odor3) dam a ge to som e fabrics and surfaces at higher concentrations 4) hi gh cost 5) possible hazards from heavy use Sm all children frequently have skin reactions to D EET. Sm all children are also m o st likely to be the individuals that develop m e urotixic ological sym p tom s from DEET. Thirt een of 14 cases of encephalopathy (toxicity of the central nervous syst em ), found in publicly available reports by a recent review (Osim itz and Grothaus 1995), were i n chi l d ren 8 y ears ol d or y ounger. Three of th ese chi l d ren di ed, al l havi ng used “heavy ”

am ounts of repellent, even though the repellent in each cas e had DEET concentrations of 20% or less. Oral i ngest i on m a y have pl ay ed a rol e i n som e of th e cases. Osi m i t z and Grothaus (1995) concl uded th at th ere i s no evidence that increased DEET concentration has an effect of the sever ity of sym p tom s . They also com p ared reports that the Poison Control Center received for DEET (6,724 in children under 6 years old dur ing a five-year period) to laundry detergent reports (10,789 in 1989) and househol d bleach (16,169 in 1989), c oncluding that accidental exposure, whi l e undesi rabl y hi gh, i s i n l i n e wi th , or l o wer th an, exposure t o other househol d chem i cal s. There is one unsubstantiated report in the Russian literature of carcinoge nic effects in rats at high doses. Three other repel l e nt m a t e ri al s are i n com m on use. Di m e th y l phthal a t e (general l y sol d as 6-12) i s not as effective as DEET against m o squitoes but still has a share of the m a rket. Citr onella-based repellents have long been

m a rket ed as candl es or i n oi l

- burni ng l a m p s. C i tr onel l ai s al so avai l abl e as a repel l e nt t o be spray e d i n ski n and cl othi ng (Natrapel ) . The th i r d m a t e ri al (Avon ski n -so-soft ) i s a popul ar bath oi l th at i s not m a rket ed as a m o squi t o repel l e nt but has, th rough word of m outh, been recogni zed fo r i t s as y e t uncharact eri zed m o squi t o repel l e nt affect

. It is as effective as DEET but it does not persist as long. On the other hand, it is mu ch cheaper, sm ells better, and apparently does not dam a ge any fabrics or surfaces. The activ e ingredient(s) of skin-so-soft has not been isolated or identified to date. It also has not unde rgone the EPA safety testing that other repellents have because it is m a rketed as a beauty aid rather than a pe sticide (Note: repellents are cla ssified as pesticides by EPA). El ectroni c m o squi t o repel l e nt devi ces whi c h are peri odi cal l y m a rket ed i n th e U.S. (usual l y by m a i l order houses) are com p l e t e l y i n effect i v e and are not based on any bi ol ogi cal rat i onal e (Fost e r & Lut e s 1985, M i t c hel l 1992, C u rt i s 1994).C. Physical Control 1. Ty pes of Habi t a t M odi fi cat i on

a. Open m a rsh wat e r m a nagem e nt (OM W M ) Ori g i n al l y devel oped for New Jersey sal t m a rshe s (Ferri gno 1970, Ferri gno & Jobbi ns 1968, Ferri gno et al

. 1969), th i s strat e gy basi cal l y at t e m p t s t o overcom e th e l i mi t a t i ons of di t c hi ng by th e i n corporat i on of other wat e r

m a nagem e nt strat e gi es. In part i c ul ar, cham pai gn pool s or reservoi rs (whi ch perm anent l y hol d wat e r and sust ai n l a rvi vorous fi sh) are creat ed (by backhoe, dragl i n e or rot a ry di t c her) i n sel ect ed t i d al pool s or l a rge shal l o w pans and are connect ed vi a sm al l shal l o w di t c hes t o surroundi ng m o squi t o breedi ng depressi ons. If ol d di t c hes are redug and used as reservoi rs, th en pl ugs mu st be i n sert ed at th e t i d al end t o prevent drai nage. Thi s cust om i zed approach t o m a rsh m a nagem e nt represent s th e l east del e t e ri ous and m o st effi ci ent nonpest i c i d al m e thod for
control l i ng sal t m arsh m o squi t o es and has been adapt e d t o New Engl and condi t i ons (B oy es and C a pot ost o 1980, Hruby et al. 1985, Christie 1990). A m a nual outlining this m e thod was de veloped by the Massachusetts Audubon Soci et y (Hruby and M ont gom ery 1986) and OM W M i s current l y bei ng pract i ced by coast a l project s i n Essex and Plym outh Counties in Massachusetts. As of 1996, OMW M had becom e the accepted technique for new salt-m a rsh wat e r m a nagem e nt work, though m a i n t e nance work rem a i n s dom i n at ed by cl eani ng exi s t i ng di t c hi ng, as opposed t o conversi on t o OM W M

. b. Other M odi fi cat i on Strat e gi es M o squito control efforts in M a ssac husetts predate m odern chem ical in secticides. Early control efforts consi s t e d of source reduct i on work, m o st l y i n sal t m a rshe s (see “Hi s t o ry of C a pe C od M o squi t o C ontrol Project , 1928-1971”). Thi s em phasi s was l a rgel y abandoned when ch eap and seem i ngl y m o re effect i v e organo-chl o ri ne insecticides becam e availabl e in the early 1950' s. Early control progr am s capitalized on cheap W P A labor but they failed to ach iev e th e lev e l o f co n tro l th at th e p u b lic h a s co m e t o expect of m odern control program s. Noneth el ess, they serve as a rem i nder that m o squito control, from its earliest in cep tio n , co n s id ered and practiced control altern ativ es to syn th e tic ch em ical p e sticid es. Except for new OM W M project s i n sal t m a rshes, m o squi t o control source reduct i on work now consi s t s p r im arily o f m a in ten a n ce wo rk o n ex istin g cu lv erts, sto r m sewers an d d itch e s. Very little n e w d itch co n s tru c tio n has taken place in recent years. Ditch cleaning, which often involve s excavating spoil with a backhoe or plow, is an activity which has drawn great concern wh en it takes place in estuarine environm en ts. This is because m a ny of theol d gri d di t c hes i n th e sal t m arsh served no real purpose for m o squi t o control but th ey mu st be re-cl eaned periodically or they them selves becom e sha llow breeding areas for saltm arsh m o squitoes.

c. Ori g i n at i on of R e quest s for Phy s i cal C ontrol

. The exem pt i on from cert a i n regul at i ons enjoy e d by m o squi t o control i s a t w o-edged sword. On th e one hand, i t enabl e s m o squi t o control project s t o m o re qui ckl y respond t o drai nage probl em s. On th e other hand, i t

m a kes th e headi ng “M osqui t o C ontrol ” part i c ul arl y desi rabl e for drai nage project s i n whi c h m o squi t o control i s , at best , a m a rgi n al goal

. Thi s pressure can com e from propert y owners, publ i c offi ci al s, or from wi th i n control project s th em sel v es. The pressure t o conduct drai nage wo rk th at does not have a m o squi t o -control com ponent mu st be resisted. The best i n t e rest s of m o squi t o control program s are se rved by conservat i v e appl i cat i on of th e defi ni t i on of

m o squi t o control , as over-use of th e wet l a nds exem pt i ons m a y resul t i n th e l o ss of those exem pt i ons. To th i s end,

m o squi t o control program s, i n conjunct i on wi th st at e a nd federal wet l a nds prot ect i on agenci es, mu st devel op a strong set of gui del i n es for al t e rat i ons exem pt

from W e t l a nds Prot ect i on Act

. 2. Ecosy s t e m changes of non-t a rget bi ot a as a resul t of phy si cal control s .
a. Salt Marsh

. New Engl and coast a l wet l a nds have been heavi l y i m pact ed by m a n (Shi sl er 1990). However, evi d ence

co n cern i n g th e n e g a tiv e im p act o f saltm arsh d itch m a in ten a n ce activ ity is m i x e d

. Th e p r in cip a l co n cern is with di sposal of th e spoi l on th e m a rsh and th e i nvasi on of upl and pl ant s th at can occur wi th even sl i ght el evat i on increases (i.e. 1-2 inches) (Miller and Egle r 1950, Buchsbaum 1994). Ditching also perm its Spartina alterniflora to i nvade th e upper m a rsh (dom i n at ed by Spart i na pat ens and Distich lis sp ica t a ) al ong th e edges of th e newl y creat ed di t c hes. There i s evi d ence t o support th e cl ai m th at th i s i n creases m a rsh product i v i t y (B uchsbaum 1994). In 1979, st aff bi ol ogi st s from th e New Engl and Di vi si on of th e U.S. Army C o rps of Engi neers (DeSi s t a& Newl i ng 1979) carri ed out prel i m i n ary i nvest i g at i on i n seve ral M a ssachuset t s sal t m a rshes t o expl ore th e i ssue of spoil deposition and upland plan t invasion. In m a ny instances they f ound little plant invasion despite evidence of previ ous spoi l deposi t i on of 2 i n ches or m o re i n depth o n th e m a rsh

. In a few lo catio n s with m i n i m a l tid al i n fl uence, som e i nvasi on by sp ecies such as com m on ragweed ( Amb ro s ia a r temisifu lia ), m a rch elder ( Iva frutescens ), and seasi d e gol denrod ( Sol i dago semprevi rens ) had occurred over t i m e. However, t h ey concl uded th at i t

was not obvi ousl y correl a t e d wi th th e spoi l i t s el f but was perhaps caused by som e other fact or associ at ed wi th th edi sturbance t o th e m a rsh. They recom m e nded th e sort of l ong-t e rm m oni t o ri ng studi es whi c h have as y e t not been carried o u t in Massach u s etts salt m a rsh e s. C l arke et al . (1984) studi ed th e effect of di t c hi ng and veget a t i on changes on th e use of th e sal t m arsh by bi rds i n R o wl ey , M a ssachuset t s . They concl uded t h at bi rduse of th e m a rsh was negat i v el y i m pact ed by m o squi t o control di t c hi ng. Thi s i s i n contrast t o th e studi es of Shi s l e r & Jobbi ns (1977) i n New Jersey m a rshes where i n crease product i v i t y was observed i n di t c hed m a rshes. Dai b er (1986) not ed th at , where di t c hes drai n pannes, bi rds that need a constant water supply (Am e rican bittern, pied-billed grebe and Am eri can coot) m a y decline. Also noted was a case where spoi l ri dges i nvade by Bacchari s and Iva caused gul l s t o seek l e ss brushy areas for nest i ng. Schei r er (1994) encouraged m o squi t o control program s t o devel op wat e r m a nagem e nt part nershi ps wi th th e U. S. Fish and W ildlife Service, especially for OM W M -t y p e m a rsh rest orat i ons desi gned t o i m prove m i grant wat e rfowl h ab itat. In a seri es of i nvest i g at i v e report s by st aff bi ol o g i sts fro m th e Natio n a l Park Serv ice, th e en v i ro n m en tal i m pact of di t c hi ng and di ki ng of sal t m a rshes i n th e Herri ng R i ver basi n of C a pe C od Nat i onal Seashore were i nvest i g at ed (Soukup & Port noy 1983, Port noy 1984a, 1984b). These report s hel d th at C a pe C od m a rsh

m a nagem e nt pract i ces were responsi b l e for th e fresheni ng, st agnat i on, aci di fi cat i on and hi gh sul f at e and al um i num concentr at i on i n di ked m a rshes. These authors suggest th at th e destruct i on of a th ri vi ng eel and herri ng fi shery i n W e l l f l eet was th e di rect resul t of th ese m a rsh di srupt i ons. However, th e m a i n di ke across th e m outh of th e Herri ng Ri ver (from Gri ffi n Isl a nd t o th e M a i n l a nd) was constr uct e d i n 1909 wi th th e m a i n object i v e of provi di ng for agricultural use of the basin. These structures are not t y pi cal of earl y m o squi t o m a rsh m a nagem e nt pract i ces i n other coast a l regi ons i n M a ssachuset t s . The i m pact m a y be l a rgel y reversi b l e i f di kes are rem oved and norm a l t i d al flo w is allo wed to retu rn to th ese areas. OMW M tailo red to th e u n i q u e ch aracteristics o f th ese sm all estu aries shoul d be expl ored as a way t o m a nage th e Ae. so llicita n s populations which are likely to replace the present Ae.
cant at or popul at i ons i f t i d al fl ow and norm a l veget a t i on and sal i n i t y are rest ored i n th ese m a rshes. Perhaps th e m o st dam a gi ng assessm ent of di t c hi ng i n sal t m a rshes was th e report of B ourn and C o t t a m (1950) i n whi c h th ey bl am ed open di t c hi ng for convert i ng up t o 90% of th e Spartina alterniflora m a rsh al ong th e Misp illio n Riv e r in Delaware to Bacchari s . However, Provost (1977) report e d th at th e area had retu rned t o Sp.

a ltern iflo ra after navigational dredging of the river had ceased and concluded that it was the dredging of the m a in ch an n e l, n o t th e m a rsh d itch i n g , wh ich h a d p e rm itted Bacchari s t o i nvade th e m a rsh (see Dai b er 1986 andB u chsbaum 1994 for revi ews of th i s debat e ). Argui ng agai nst si gni fi cant wat e r-t abl e l o weri ng i n sal t m a rshes i s th e strong affinity for water exhi bited by salt m a rsh soils. Because perm eab ility is so low, the water table m a y be l o wered onl y wi th i n a m e t e r or so of th e di t c h i t s el f (B al l i ng and R e sh 1982). Grid d itch i n g , ev en if n o t th e m a rsh d e stro yer so m e claim it to b e , still red u ces stan d i n g water o n th e m a rsh and creat es an unnatu ral and aesth et i cal l y unpl easi ng vi ew. Open m a rsh wat e r m a nagem e nt was desi gned t o m o re clo s ely ap p r o x i m a te th e d i v e rsity o f th e n a tu ral m a rsh wh ile elim in atin g th e sh allo w p a n n e s in wh ich m o sq u ito es breed. W o l f e (1996) revi ewed t h e effect s of OM W M on num erous t i d al m a rsh resources. OM W M sy st em s t e nded t o enhance t i d al exchange and sal i n i t y i n m a rshes th at were convert ed from gri d di t c hi ng. Except where spoi l pi l e s were l e ft (i m p roperl y ) on th e m a rsh, veget a t i on change was sl i ght and favored salt-m a rsh species such as Spart i na pat ens and Distich lis sp ica t a . Sm all ch an g e s in elev atio n d u e to sp o il d e p o s itio n so m e tim es resu lt in i nvasi on by Iva, Bacchari s , and Phragmi t e s . Salt-m a rsh sn ails ( Mel ampus bi dent at us ) have decl i n ed i n som e OM W M si t e s but not i n others. Si m i l a r m i xed obs ervat i ons have been m a de for m a rsh peri wi nkl e ( Litto rin a irrorata) and fiddler crabs ( Uca speci es). M a rsh fi sh popul at i ons are, by desi gn, enhanced by OM W M . However, changes i n speci es com posi t i on m a y occur wher e exi s t i ng pool s are deepened. M u m m i chogs ( Fundul us h e tero clitu s )an d sp o t fin k illifish ( Fundul us l u ci ae ) shoul d decrease whi l e sheepshead m i nnows ( C y pri nodon vari egat us ), in lan d silv ersid e s ( Men id ia men i d i a ) an d rain water k illifish ( Lucani a parva ) shoul d i n crease (Tal bot et al . 1986). The sm al l reservoi rs are not part i c ul arl y at tr act i v e t o bi rds and th e m i nor changes i n hy drol ogy , fl ora and i nvert ebrat e fauna caused by OM W M do not cause si gni fi cant changes i n bi rd use on OM W M si t e s. Effect s on

m a m m a ls are not well docum ented. OMW M has had no long-te rm detrim ental effects on water quality. As a result, W o l f concl udes th at , “Open M a rsh W a t e r M a nagem e nt i s an envi ronm ent a l l y focused m a nagem e nt t ool th at i s desi gned t o be com p at i b l e wi th natu re rath er th an com p et e wi th i t
. ” Of course, th e t echni que i s new enough th at l ong-t e rm m oni t o ri ng i s requi red t o ensure th at al t e red si t e s rem a i n funct i onal sal t m a rshes. b. Freshwat er W e t l a nds (excl u si ve of Vernal Pool s). Pal u stri ne wet l a nds, i n cl udi ng

em ergent , scrub-shrub and forest ed wet l a nds, are th e dom i n an t system in wh ich Massach u s etts fresh water p h y sical control take place. In the vast m a jority of cases, this work consists of m a intaini ng existing ditching designed to

rem ove st andi ng wat e r from th e wet l a nd, th ereby reduci ng m o s q u ito -b reed in g h ab itat. Fo r m o st MCPs, th is typ e o f work (source reduct i on) m a kes up a l a rge percent a ge of th ei r control effort . Though reduci ng st andi ng wat e rcertain ly red u ces m o sq u ito b r eed in g , th ere h a s b een little research co n cern i n g th e o v e rall effects o f th ese alteratio n s on th e m odi fi ed wet l a nd. Di t c h sy st em s can becom e probl em s i n th ei r own ri ght , produci ng m o squi t o es i f l e ft

unm ai nt ai ned. M o st of th ese sy st em s were never desi gned speci fi cal l y for m o squi t o control and th ei r other, pri m ary funct i on, such as rem ovi ng runoff from l a rge parki ng l o t s , m a y cause consi d erabl e dam a ge t o th e ecosy st em , leaving the MCP to clean up, or at l east deal with, som e one else’s m e ss. Th e m a j o rity o f d r ain a g e system s cu rren tly m a in tain ed b y MCPs were n o t in itially co n s tru c ted b y MCPs and th e effort of M C Ps t oday i s al m o st ent i r el y restri ct ed t o rem ovi ng bl ockages t o exi s t i ng fl ows, rath er th an enl a rgi ng or strai ght eni ng channel s t o i n crease fl ow. M o st freshwat e r drai nage i s an i nheri t e d probl em whi c h requires intervention not because of m o squito-control activities but because of the activities of others. Road sand and y a rd wast er represent t w o of th e m o st com m on obs tr uct i ons M C Ps are cal l e d upon t o rem ove from exi s t i ng stream s and drai nage net w orks. New devel opm ent s al so can cause dram atic changes in th e sed i m e n t lo ad in
stream s, despi t e regul at i ons desi gned t o prevent such probl em s. Road sand, yard waste and increased sedim e nt load from developm ent can all have im pacts on a stream that are as greater or greater than re gul ar di t c h m a i n t e nance. Because MCPs are often involve d in rem oving m a nm ade sedim e nt s from stream s, a system under appropri a t e di t c h m a i n t e nance m a y funct i on m o re cl osel y t o a natu ral sy st em th an one i n whi c h m a nm ade wast es are allowed to accumu late unabated. The appropriate re sponse by the MCP in such cases is not obvious because, al though th e probl em , and i t s cause, m a y not be m o squi t o rel a t e d, th e m o squi t o control program m a y be th e organi zat i on best equi pped, both from a nd equi pm ent and a tr ai ni ng perspect i v e, t o rect i f y th e si tu at i on. Si nce m o squi t o control project s cam e i n t o bei ng i n M a ssachuset t s , th e percei ved val u es of wet l a nds have changed. Once shunned as disease-bear ing waste lands, best suited for dum pi ng, draining or filling, wetlands are

n o w v i ewed in a mu ch m o re p o s itiv e way. Th ey are im p o r tan t wild life h ab itats, p e rfo rm a my riad o f water q u a lity

m a i n t e nance funct i ons, and serve as fl ood control , eros i on, ground-wat e r recharge and wat e r suppl y regul at ors (Tiner 1989). Mosquito control program s have been slow in adapting to the increased value accorded wetlands. On
th e one hand, l ong-resi dual and/ or broad-spectrum pest i c i d es are no l onger used i n wet l a nds i n M a ssachuset t s . On th e other hand, th ere i s real resi st ance t o hal t i ng m a i n t e na nce work i n drai nage net w orks th at m a y be seri ousl y dam a gi ng wet l a nd habi t a t
. There has not been a great deal of work done speci fi cal l y on th e effect s of phy si cal control for m o squi t o es on non-t a rget organi sm s. Therefore th e fol l o wi ng di scussi on i s based on th e general effect s th at can be expect edwhen wet l a nd al t e rat i ons are m a de. C a re shoul d be t a ken i n ext e ndi ng th ese general concerns t o m o squi t o control in Massach u s etts. Fo r ex am p l e, ch an n e lizatio n (straig h t en in g ) o f n a tu ral stream s is n o t p e rm itted in Masach u s etts, where program s are requi red t o fol l o w th e natu ral m eanders of th e stream . The th ree broad cat egori e s of wet l a nds alteratio n are o u trig h t lo ss, ch an g e s in th e ab io tic system an d ch an g e s in th e b i o tic co m mu n ity. Fillin g an d/ o r drai ni ng wet l a nds t o convert th em t o upl and i s a m o squi t o -control pract i ce th at has been al l but el i m i n at ed i n Massachusetts. There is no indication that MCPs are in t e nt i onal l y reduci ng wet l a nd acreage i n order t o control

m o squi t o es. However, th e fact th at th e wet l a nds bounda ry rem a i n s essent i a l l y unm oved by a m o squi t o -control al t e rat i on does not m ean th at prof ound al t e rat i ons have not occurred. C h anges i n th e abi o t i c sy st em and bi ot i c com muni t y are deepl y i n t e rt wi ned, though phy si cal control m o st

o f

ten cau ses ab io tic ch an g e s wh ich th en cause bi ot i c changes. For channel s changes i n fl ow rat e s, m i crohabi t a t s , sedi m e nt l o ad, sedi m e nt at i on, and groundwat er i n t e ract i ons can al l occur. For wet l a nds (out si de of channel s ) changes can include lost water-storage capaci t y , i n creased sedi m e nt at i on and pol l u t a nt l o ad, changes i n wat e r depth, and changes i n groundwat er hy drol ogy . W h en a stream i s al t e red t o i m prove wat e r fl ow for th e purpose of rem ovi ng st andi ng wat e r, ei th er wi th i n the stream or from adj acent wetlands, a num ber of change s m a y take place. By defin ition, im proving water flow increases runoff. This, in turn, m a y decrease the surface-water storage capacity of the wetland system and decrease th e cap ab ility o f th e wetlan d to retain lo ad (su s p e n d e d so lid s). Th is m a y in crease th e lo ad o f th e water m o v i n g th rough th e stream (B rown 1988). Increasi ng runoff i n t o a gi ven stream t e nds al so t o i n crease erosi on, whi c h further increases load (W illiam s & Feltm antle 1992). Not only is total flow increased, but alteration tends to i n crease peak fl ow, whi c h i s associ at ed wi th reduct i ons i n faunal di versi t y (Hy n es 1972). The effect s of i n creased fl ow and l o adi ng are m a ny . At i t s m o st obvi ous, hi gher peak fl ows i n crease scouri ng of th e stream bed by gravel and sand bei ng tr ansport e d by th e wat e r. B o t t o m dwel l i ng ani m al s are ei th er affect ed on-si t e or swept downstr eam , l eavi ng an i m poveri shed com muni t y as fl ows retu rn t o norm a l (Hy n es 1972). Increased fl ows can al so rem ove organi c m a t t e r, l eavi ng a sandy bot t o m on whi c h m acrofauna i s reduced (W ard 1992). As st at ed earl i e r, hi gher peak fl ows al so encourag e erosi on, a process th at can i n crease stream l o ad l ong after sedim e nt controls put in place duri ng the actual drainage work are rem oved. Hig h lev e ls o f su sp en d e d so lid s alter th e stream h ab itat b y : 1. reduci ng l i ght penetr at i on2. reduci ng pri m ary product i on 3. al t e ri ng th e tr ophi c structure 4. al t e ri ng nutri ent dy nam i cs 5. changi ng th erm a l condi t i ons 6. reduci ng oxy gen l e vel s (W ard 1992). These effects can, in turn can have th e following im pacts on the stream fauna: 1

. ab ratin g resp irato r y ep ith elia 2. cl oggi ng respi r at ory structures 3. reduci ng feedi ng rat e s 4. reduci ng feedi ng effi ci ency 5. i n creasi ng exposure t o t oxi ns 6. reduci ng vi si on 7. i nduci ng organi sm s t o dri f t
. Al l of th ese effect s can al t e r behavi or pat t e rns, change pr edat or/ p rey i n t e ract i ons and change th e out com e of i n t e r and intra-specific com p etition (W ard 1992). M a i n t e nance for th e purpose of reduci ng m o squi t o breedi ng al so i n cl udes rem ovi ng obstr uct i ons wi th i n stream s. Tree branches and fal l e n tr ees are a part i c ul arl y i m port a nt part of th e stream envi ronm ent , provi di ng food, living space, concealm e nt from predator s, protection from abiotic conditions and em ergence sites (W ard 1992). They al so provi de vari ed m i crohabi t a t s by deepeni ng and sl owi ng fl ow on th e upstr eam si de and oft e n creat i ng deeper pools on the downstream side. Rem oving these obs tructions dim i nishes the variability of the stream ecosystem
. At th e o th e r en d o f th e flo w -rate sp ectru m , in creasin g p eak flo w m a y lead to faster d r yin g in in term itten t stream s. Th e in sect fau n a(an d b i o tic co m mu n ity in g e n e ral) o f in term itten t stream s d o e s n o t o v e rlap to a g r eat extent with that of perm anent stream s (W ard 1992). As a ge neral rule, this is because interm ittent stream dwellers have evol ved t o deal wi th th e dry i ng down stream . Survi v al m echani s m s i n cl ude l eavi ng th e stream (swi m m i ng down stream or em ergi ng as l a nd-l i v i ng form s), survi v i ng i n cray fi sh burrows or rem a i n i ng pool s of wat e r, bury i ng either at shallow depths or quite d eeply into the substrate or hiding under rocks or leaflitter within or along the
stream course (W ard 1992). Stream s th e dry m o re qui ckl y , and st ay dri e r l onger, m a y di srupt al l of th ese t echni quesas i n sect s th at em erge as adul t s m a y not have enough t i m e t o com p l e t e devel opm ent (the pri m ary exam pl e bei ng

m o squi t o es th em sel v es), rem a i n i ng pool s m a y decrease i n si ze and num ber and shal l o w burrows and hi di ng si t e s under rocks and leaf litter m a y becom e too dry to support the fauna hiding there. The effect of rapid drying brings up the aspect of the hyporheic zone. This is the interstitial space between
th e substr at e part i c l e s i n a stream bed. W i th i n th e hy porhei c zone th e m acrofauna can fi nd shel t e r from fl oods, drought and extrem e tem p eratures, can find suitable and pred ictable conditions for im m o tile stages such as eggs, pupae and di apausi ng ny m phs and l a rvae and, part i c ul arl y for earl y i n st ars, prot ect i on from predat i on. Gravel beds provi de th e best hy porhei c zones and ani m al s can oft e n be found m a ny feet down (W ard 1992). Thi s hy porhei c zone fauna can be an im portant s ource of recolonizing organism s after a stream bed is denuded (W illiam s & Feltm antle 1992). Excessive drying can reduce the viability of the hyporheic zone. Sedim e ntation, both within stream beds and in wetlands into which stream s flow, is a problem because it can alter the stream bed com position, thereby altering the fauna, and can clog interstitial spaces, thereby reducing
th e hy porhei c zone and/ or reduci ng groundwat er recharge. Sedi m e nt s can al so i n crease exposure t o pol l u t a nt s as th ey provi de addi t i onal si t e s for pol l u t a nt bi ndi ng whi l e su spended, and th en carry th e pol l u t a nt s t o th e benthi c fauna. M C Ps rout i n el y conduct m a i n t e nance t o rem ove sedi m e nt s. Therefore, t h ere i s good reason t o expect t h e overal l effect of m a i n t e nance m a y be t o reduce th e negat i v e i m pact s of sedi m e nt at i on wi th i n th e stream . In such cases, i t woul d be preferent i a l t o devel op sy st em s desi gne d t o prevent th e deposi t i on of road sand i n t o drai nage system s, rath er th an to p r ev en t th e rem o v a l o f th at sand, once i t has ent e red th e sy st em . R e m ovi ng th e dense,
rot t i ng m a sses of grass cl i ppi ngs th at are dum ped i n t o stream s by propert y owners shoul d al so i m prove overal l
stream q u a lity.

Up t o th i s poi nt th e di scussi on has focused on th e stream i t s el f, but freshwat e r wet l a nd al t e rat i ons are t y pi cal l y desi gned t o change st andi ng-wat e r wet l a nds t o soi l

- satu rat e d wet l a nds (New Jersey DEP 1997). The obvi ous probl em i s th at any organi sm th at requi res st andi ng wat e r for peri ods other th an peak fl oodi ng, th e wet l a nd

m a y becom e unusable. Mosquitoes fit th is definition perfectly, but so do m a ny other organi sm s. Many species of

am phi bi ans use t e m porary st andi ng wat e r for breedi ng and are becom i ng scarce as these h ab itats are elim in ated

. Increased drai nage al so m a y have an effect on groundwat er. Preci pi t a t i on and i n fl ow det e rm i n e th e

am ount of water initially available to a wetland for gr ound water recharge (Todd 1972). Increasing the am ount ofwat e r rem oved from th e wet l a nd pri o r t o percol at i on dow nwards can decrease the cap acity o f th e wetlan d to recharge groundwat er suppl i e s. Not onl y can groundwat er recharge wi th i n th e wet l a nd l o wered, i t can be l o wered wi th th e out fl owi ng stream as wel l

. Duri ng peak fl ows, water m o v e s fro m th e stream in to th e su b s trate an d raises
th e wat e r t abl e (i ncreases groundwat er). As th e fl ow decl i n es, groundwat er percol at es back i n t o th e stream (i f i t does not , th e stream dri e s out ). B y el i m i n at i ng upstr eam reservoi rs (wet l a nds), m o re wat e r fl ows out of th e sy st em initially, leaving less water within the system . As water le vels fall, groundwater discharg e occurs sooner than m i ght otherwise be the case. If nothing else , stream depth is liable to vary m o re widely after adjacent wetlands are red u ced to so il satu ratio n . W h at i s m o st needed i s a com p rehensi v e underst a ndi ng of th e tr ue ecol ogi cal cost s of phy si cal al t e rat i ons for m o squito control. This is particularly im portant because, although the environm ental effects of pesticides receive the lion’s share of concern, it is possible that the long-term effects of physical controls m a y have a greater effect on th e envi ronm ent th an does pest i c i d e use (B uchsba um 1994). Thi s m a y be especi al l y tr ue t oday wi th th e swi t c h from broad-spectrum , m o re-persi st ent pest i c i d es t o m e thoprene and B t i

. New Jersey has recently updated it’s B e st M a nagem e nt Pract i ces for M o squi t o C ontrol and Freshwat er W e t l a nds M a nagem e nt and M a ssachuset t s shoul d l ook t o such gui del i n es t o est abl i s h a prot ocol for phy si cal control i n freshwat e r wet l a nds. At a m i ni mu m th e com m on-sense requi rem e nt s th at al l al t e rat i ons be pl anned (not random ), necessary , and desi rabl e shoul d be ri gorousl y appl i e d t o al l M C P wat e r m a nagem e nt project s regardl e ss of whether
th ey are defi ned as new or m a i n t e nance work. Th e North East M a ssachuset t s M C P St andards for Di t c h M a i n t e nance (Appendi x F) can be vi ewed as a st art i ng poi nt for a st at ewi d e prot ocol , though i t fai l s t o m e nt i on th e need for sedi m e nt control s duri ng m a i n t e nance work and l eaves th e M C P superi nt endent wi th wi de l a t i tude for det e rm i n i ng th e necessi t y of a gi ven project . A res ponse from th e M a ssachuset t s Audubon Soci et y (al s o Appendi x F) t o th ese St andards provi des addi t i onal com m e nt s whi c h de serve consi d erat i on when a prot ocol i s est abl i s hed.

c. Vernal Pool s. Vernal pool s form i n c ont ai ned depressi ons i n whi c h wat e r st ands for a peri od of several m onths, general l y from m i d- t o l a t e wi nt er th rough th e spri ng. W a t e r ei th er com e s i n th e form of

snow m e l t or spri ng preci pi t a t i on or can be a resul t of a ri si ng wat e r t abl e. Som e pool s dry down wi th i n t w o or th ree m onths, others m a y onl y dry when th e wat e r t abl e i s l o wer th an norm a l , resul t i ng i n a pool th at i s sem i

perm anent
. R e gardl e ss, a key feature of vernal pool s i s th at th ey undergo peri ods of dry down. Vernal pool s m a y have perm anent i n l e t s but do not have perm anent out l e t s (Kenney 1995).There are num erous obl i g at e speci es for vernal pool s, th e m o st vi si bl e of whi c h i n cl ude fai r y shri m p , th e wood frog ( Rana syl v at i c a ) and several speci es of sal a m a nder ( Ambyst oma spp.). The M a ssachuset t s Di vi si on of Fi sheri e s and W i l d l i f e (Publ i cat i on #15498-10-600-6-1-88C .R ) has creat ed guidelines for certifying vernal pool ha bitat on the grounds that m a ny vern al pool species cannot successfully survi v e wi thout vernal pool s and th at vernal pool s are under pressure from cont i nued devel opm ent wi th i n th e st at e. The cert i f i cat i on program i s coordi nat e d by th e Natu ra l Heri t a ge and Endangered Speci es Program (NHESP - see next sect i on). “Aut om at i c” prot ect i on i s gi ven t o vernal pool s onl y i f th ey 1. occur ei th er (a) wi th i n th e 100 y ear i n l a nd fl ood pl ai n or (b) on “i sol a t e d l a nd subject t o fl oodi ng” (as defi ned i n th e regul at i ons at 310 C M R10.57 (2)(b)); and 2. i t s exi s t e nce and l o cat i on has been cert i f i e d by th e M a ssachuset t s Di vi si on of Fi sheri e s an d W ild life. C u ri ousl y , upl and vernal pool s are not grant e d th e sam e prot ect i on but m a y be cert i f i e d as vernal pool s. The NHESP does not seek out pool s t o cert i f y ; i t cert i f i e s subm i ssi ons from th e publ i c . A gui debook for vernal pool certificatio n ( W i cked B i g Puddl es ) i s avai l abl e t o hel p those who wi sh t o subm i t a vernal pool si t e for cert i f i cat i on (Kenney 1995). Mo sq u ito es, p a rticu l arly Ae. canadensi s , al so use vernal pool s for breedi ng. From a control perspect i v e, vernal pools are im portant because, due to increasing protection, ve rnal pool habitat is ofte n left undeveloped while the land adjacent to the pool is built up. As a result, m a ny new devel opm ents surround known breeding sites. R e gardl e ss of th e wi sdom of devel opi ng so cl ose t o ve rnal pool s, m o squi t o -control personnel are charged wi th
control l i ng th e m o squi t o es com i ng from th e pool

. d. R a re and Endangered Speci es. Hy nes (1972) st at es th ree axi o m s of runni ng wat e r b i o tic co m mu n ities: 1. The great er th e di versi t y of the abiotic system , the greater th e num ber of species within the system
. 2

. Th e m o re co n d itio n s d e v i ate fro m th e n o r m a l, th e fewer sp ecies will b e p r esen t, b u t th o s e rem a in in g will b e p r esen t in g r eater n u m b e rs. 3. The l onger a sy st em i s l e ft undi sturbed, th e ri cher and m o re st abl e i s th e bi ot i c com muni t y . Operat i ng under th e assum p t i on th at i t

i s rare and endange red speci es whi c h are m o st l i k el y t o be l o st from th e sy st em fi rst , th e above st at em ent s woul d suggest th at re duct i ons i n habi t a t di versi t y , al t e rat i ons from th e natu ral state, an d freq u e n t d i stu rb a n ces will all wo rk ag ain s t th ese sp ecies. Ch an n e lizatio n o f stream s red u ces d i v e rsity b yrem ovi ng obstr uct i ons, strai ght eni ng th e channel and i n creasi ng fl ood l e vel s . W e t l a nds changed from st andi ngwat e r t o satu rat e d-soi l regi m e s have been drast i cal l y change d from th ei r natu ral st at e. M a i n t e nance i s ongoi ng, as i s the disturbance it causes. The key quest i on i s , however, t o what ext e nt does m o squi t o control contri but e t o th e above probl em s. Fi rst , M a ssachuset t s M C Ps do not channel i ze stream s, as th ei r cert i f i cat i on m a nual cal l s for fol l o wi ng th e exi s t i ng m eanders. Second, M C Ps work nei th er i n hi st ori cal l y undi sturbed, nor current l y undi sturbed stream s. There i s every reason t o argue th at th ere i s no speci fi c “natural ” st at e th at can be assi gned a di t c h dug by m a n and in term itten tly filled with ro ad san d an d g r ass clip p i n g s . Ev en with n a tu ral stream s, th e “n atu r al” h ab itat in wh ich
th ey fl ow has l ong been al t e red and cont i nues t o be al t e red. The Natu ral Heri t a ge and Endangered Speci es Program (NHESP) was creat ed i n order t o conserve and prot ect those pl ant s and ani m al s not hunt ed, fi shed, tr apped or com m e rci a l l y harvest e d i n th e st at e. The program ’s hi ghest pri o ri t y i s t o i nvent ory ra re and endangered speci es and t o deve l op conservat i on pl ans th rough research,

m a nagem e nt and habi t a t prot ect i on for those speci es. One such program th at di rect l y i m pact s m o squi t o control i s th e vernal pool cert i f i cat i on program m e nt i oned above. The NHESP al so revi ews proposed al t e rat i ons t o wet l a nds habi t a t s under th e W e t l a nds Prot ect i on Act (M .G.L. c. 131, s. 40 and regul at i ons 310 C M R10.00). NHESP has produced a seri es of est i m at ed habi t a t m a ps for rare and endangered speci es ( Massach u s etts Natu ral Heritag e Atlas ) whi c h proponent s of a gi ven al t e rat i on are required to check. Should a project fall within an estim ated habitat, NHESP w ill then determ ine if the area to be altered is actu a l wetlan d h ab itat fo r a state-listed sp ecies. Th e resu lts o f th e NHESP d e term in atio n are g i v e n to th e i nqui ri ng M C P. The M a ssachuset t s Endangered Speci es Act (M .G.L . c. 131A and regul at i ons 321 C M R10.00) prohi bi t s th e “t aki ng” of rare pl ant s or ani m al s. From a m o squi t o -control perspect i v e, th e m o st i m port a nt defi ni t i on of “tak in g ” is d i sru p tin g n e stin g , b r eed in g o rfeed in g sites o f an im als o rk illin g o rcu ttin g a p l an t. Asid e fro m d i rectly prot ect i ng rare or endangered speci es, th i s Act al so al l o ws areas t o be desi gnat e d “si gni fi cant habi t a t s .” Al t e rat i ons in “sig n i fican t h ab itats” req u i re a p e rm it fro m th e Div i sio n o f Fish eries & W ild life. In Massachusetts, the species that have caused m odifi cations in m o squito control practices are the Bluespot t e d sal a m a nder ( Ambyst oma l a t e ral e ), M y st i c Val l e y am phi pod ( C r angonyx aberrans ), and banded bogs k i mme r( Willia mso n i a lin tn eri ). In addi t i on, di t c h m a i n t e nance i n vernal pond areas has been curt ai l e d t o prot ect th is typ e o f h ab itat. Oth e r an im als fo r wh ich co n cern s have been rai s ed are th e y e l l o w-spot t e d tu rt l e and osprey

. The presence of a threaten ed species need not prevent water m a na gem e nt, however. In the East Volusia Mosquito Control District in Daytona Beach, Florida, OMW M was carried out in a salt m a rsh that contained the Atlan tic salt m a rsh sn ak e ( Nero d i a cla r kii ta en ia ta ). An observer wal k ed i n front of th e di t c hi ng m achi n ery and

wo rk was h a lted u n til o b s erv e d sn ak es left th e area. In p r actice th e sn ak es were d i fficu lt to sp o t an d sev e ral were seen in the freshly cut ditches behind the ditcher. Two dead snakes were found, and assum e d killed by the work. The dead snakes were handled as “inc idental take” and placed on ice for de livery to the Florida Gam e and Fresh W a t e r Fi sh C o m m i ssi on (Goode 1996). W i th an i n creased underst a ndi ng of th e ecosy st em s i n whi c h m o squi t o control takes place, m o squito control projects should im prove their ability to work in areas c ontaining endangered species with m i nim a l im pact to those species. Un d e r th e cu rren t system m o sq u ito -co n tro l m a in ten a n ce activ ities are ex em p t

fro m th e Massach u s etts W e tland Protection Act, leaving only th e federal 401 W a ter Quality Certifica tion Act and both the Massachusetts and federal Endangered Species Act as m e thods for regulating m a intenance. Unfortunately, water quality, while i m port a nt , does not address th e i ssue of changi ng habi t a t and th e presence or absence of a rare and endangered sp ecies h a s little to d o with th e m e rits o f a g i v e n p r o j ect. Rare an d en d a n g e red sp ecies will p r o b ab l y in crease in th eir im p act fo r sev e ral reaso n s . First, as d a ta is collected on these species, additional species and additi onal habitats will m o st likely com e under protection. Second, resi dent i a l areas are creepi ng cl oser t o wet l a nds areas. The net effect i s th at th e cl ash bet w een econom i c developm ent and environm ental protection will likely increas e, with m o squito control being one com ponent of an i n t e nse debat e . Agai n, a m o re com p rehensi v e underst a ndi ng of th e tr ue ecol ogi cal effect s of m o squi t o control i s req u i red to b e tter d e term in e th e co st/b en efit ratio fo r d i fferen t typ e s o f m o sq u ito co n tro l. D. Food W e b Effect s of M o squi t o C ontrol

. Throughout th ei r l i f e cy cl e m o squi t o es are a part of th e food web, both as consum er s and prey . As l a rvae

m o st speci es feed on al gae, prot ozoa, and organi c debri s (Pennak 1953). As adul t s th ey dri nk nect ar and th e fem a l e s of m o st speci es t a ke bl ood m eal s from a wi de vari et y of ani m al s. Larval m o squi t o es are eat en by an i m pressi ve array of ani m al s (B at es 1949) whi l e adul t m o squi t o es are t a ken by spi d ers, predat ory fl i e s, odonat e s,bats and birds (Collins and W a shino 1985). Given that m o squitoes are so thoroughly em bedded in the food web,
th e quest i on ari s es as t o th e effect of rem ovi ng a l a rge percent a ge of th e m o squi t o es from th at food web. At

fi rst gl ance, th e effect woul d appear t o be l a rge, part i c ul arl y i n habi t a t s wi th dense l a rval popul at i ons. Ho wev e r, m o sq u ito es are r-strateg ists, in th at th ey p r oduce l a rge num bers of eggs th at devel op qui ckl y (when i m m e rsed i n wat e r) t o adul thood. M o st pest speci es seek out t e m porary and spat i a l l y di sconnect ed habi t a t s for breedi ng and can com p l e t e a breedi ng cy cl e l ong before an adequat e predat or com p l e x can devel op. M o squi t o es are, th erefore, a hi ghl y unpredi c t abl e food source for predat ors, and predat i on rat e s mu st be equal l y unpredi c t abl e (this section will focus on predation, as parasites a nd pathogens are not widesp read control agents in Massach u s etts). Th is is b o r n e o u t b y th e fact th at m o sq u ito p r ed ato r s are g e n e ralists wh ich can read ily switch to other prey when m o squitoes becom e scarce (Collins and W a shino 1985). In a study in Florida, im m a ture

m o squi t o es m a de up over 50% of th e di et of several speci es of sal t m arsh fi sh ( Fundul us conf l u ent u s, Lucani a parva, Gambusi a a. hol brooki ). But each of these species fed on othe r item s as well, including copepods, shrim p , other fi sh and even som e pl ant m a t e ri al (Harri ngt on and Harri ngt on 1961). One i m port a nt poi nt regardi ng predat i on and l a rval broods i s th at th e concept s of handl i ng t i m e and satiation com e in to play (Varley et al. 1973). A predat or mu st spend a certain am ount of tim e with each prey. Hydrophilid larvae took several m i nutes to feed on larvae and pupae taken in a panne in Tiverton, Rhode Island (C hri s t i e , pers. observat i on). Not onl y does i t t a ke t i m e t o cat ch and eat th e prey , but i nvert ebrat e predat ors are typ i cally n o t mu ch larg er th an th e m o sq u ito larv ae th ey are attack in g . Satiatio n mu st p l ay a ro le in lim itin g p r ed ato r t a ke, part i c ul arl y when m o squi t o num bers are hi gh. Predat ors can pl ay an i m port a nt rol e i n regul at i ng m o squi t o num bers i n som e si tu at i ons. That m o squi t o es are absent from wat e rs wi th fi sh popul at i ons i s wel l known. Less wel l known i s th e i n fl uence of chaobori d l a rvae, whi c h can severel y reduce m o squi t o popul at i ons i n vernal pool s (M orri son and Andreadi s 1990). In th i s case th e l a rvae are present i n snow-m el t pool s for approxi m a t e l y t w o m onths, so predat i on has t i m e t o operat e as a regul at i ng m echani s m . Al though adul t m o squi t o es are eat en by num erous predat ors, i t i s rare th at th ey m a ke up an appreci abl e proport i on of th e di et of any one predat or. One except i on i s th e spi d er Tet r agnat ha mont ana fo r wh ich , in Po lan d ,
m o squitoes m a de up 74% in June and 62% in July of all prey captured (Collins and W a shino 1985). Bats and purpl e m a rt i n s are not effect i v e m o squi t o predat ors nor do m o squi t o es form a si gni fi cant part of th ei r di et
.Fro m a m o sq u ito -co n tro l p e rsp ectiv e, th e m o sq u ito es t o be control l e d are, for th e m o st part , those whi c h have escaped predat i on t o becom e predat ors i n th ei r own ri ght . In th e absence of sci e nt i f i c dat asupport i ng th e necessi t y of m o squi t o es i n th e di et s of speci fi c ani m al s, rem ovi ng m o squi t o es from th e food web by chem i cal , bi ol ogi cal or phy si cal control rem a i n s an easi l y just i f i abl e act i v i t y . Even so, control personnel shoul d t a ke care t o avoi d chem i cal appl i cat i ons where m o squi t o l a rvae are not present or are present i n very sm al l num bers, shoul d use
control m easures th at do not harm exi s t i ng predat or com p l e xes, and shoul d l i m i t control t o areas where control i s necessary, allowing natural cycles to c ontinue in areas where hum an activity a nd th e ri sk of di sease tr ansm i ssi on i s slight. One argum ent m a de in favor of Altosid is that it does not kill the young larvae, leaving them available as food for th e exi s t i ng predat or com p l e x. Up t o th i s poi nt , th e di scussi on has focused on th e effect of chem i cal control (i ncl udi ng Ba cillu s product s and IGR s ) of m o squi t o popul at i ons on other speci es. W i th i n th e cont ext of bi ol ogi cal control , one of th e pri m ary

reasons Gambusia are not being used in Massachusetts is the fear that they m i ght displ ace native species of fish, th u s alterin g th e n a tu ral b i o t a, n o t b y p r ed atio n b u t b y co m p etitio n fo r th e sam e reso u r ce. Phy s i cal control by wat e r m a nagem e nt m a y i n crease predation, as in OMW M , or m a y elim inate predator and prey as when wet l a nds are drai ned t o soi l satu rat i on. M o squi t o breedi ng mu st be thoroughl y docum ent e d before new work is done. Because disturban ces m a y displace som e species, and b ecause predator species tend to rebound

m o re slowly than their prey, m a intenance work should be conducte d only when necessary. E. No Program An o th e r altern ativ e strateg y to cu rren t m o sq u ito co n tro l p r actice is n o co n tro l. Man y co m mu n ities in Massachusetts have chosen this option. These town are usually outside of the enzoo tic EEE zone so the risk of h u m an d i seases tran sm itted b y m o sq u ito es is v i ewed as p r actically n il b y th ese co m mu n ities. In ad d itio n , th ey are not l o cat ed near sal t m a rshes and th ei r at t e ndant pest m o s qui t o probl em s. The m i d-sect i on of M a ssachuset t s , where

m o st no-control com munities occur, also has a m o re ru ral character, less wetland , lo wer hum an populations, and a lower m ean fam ily incom e than m o st eas t e rn areas wi th organi zed m o squi t o control program s. In general , th e vi ew

o f

th ese co m mu n ities is th at th e an ticip ated b e n e fits fro m m o sq u ito co n tro l d o n o t o u t weig h th e an ticip ated co sts and percei ved ri sks. A m o re preci se way of pol l i ng th e publ i c and confi r m i ng th i s opi ni on woul d be th rough est abl i s hi ng th e Hum a n Annoyance Threshold (HAT) for the town. Com mun ities in which the HAT is below the actual annoyancel e vel shoul d be persuaded t o choose th e no control opt i on si nce just i f i cat i on for control i s l acki ng unl ess a docum ented disease threat exists. In som e com munities, biting annoyance is created by a com b ination of biting insects (i.e. m o squitoes, bl ack fl i e s, bi t i ng m i dges and t abani ds) whi c h requi re com p l e t e l y di fferent control approaches. M a ny peopl e do not recognize the difference between these ins ects, especially in dim evening light. It is critical to accurately identify
th e bi t i ng i n sect s actual l y responsi b l e for th e hum an annoy an ce. In general , bl ack fl i e s and t abani ds onl y cause annoyance during the daytim e while m o squitoes and b iting m i dges are m o st annoyi ng from 6-10 PM. The HAT level for tabanids and biting m i dges is likely to be less th an for m o squitoes because of their m o re painful bites. Perhaps part of the reason why Berkshire County com munities have supported a MC program while other W e stern Massachusetts com munities have not, lies in the fact that this region suppor ts m a ny sum m e rtim e outdoor activities (e.g. cam ps, resorts, golf courses, Tanglewood, et c.). In addition, this m o re m ountainous region has a significant black fly annoyance problem s uperim posed on top of the m o squito problem . Vacationers are likely to have a l o wer HAT th an perm anent resi dent s si nce th ey are spendi ng m o re t i m e and m oney on out door recreat i onal activ ities. In addi t i on t o ri sk-benefi t consi d erat i ons, other cr i t e ri a for wei ghi ng th e control /no control opt i on are 1) the feasibility of successfully reduci ng annoyance below the HAT level, a nd 2) the adequacy of com munity resources for reducing annoy ance to acceptable levels. Towns wi th l a rge areas of m o squi t o -produci ng freshwat e r wet l a nd shoul d recogni ze th at effect i v e

m o sq u ito co n tro l in th ese h ab itats is d i fficu lt at b e st an d o f ten im p o ssib l e. As in d i cated earlier in th is rep o r t, perm anent wet l a nds do not usual l y produce l a rge num bers of pe st m o sq u ito es b u t in situ atio n s wh ere th ey d o , th e public needs to be aware that these wetlands are a valuable resource that mu st be prot ect ed from si gni fi cant perturbat i on and th at opt i ons for m o squi t o control are th erefore few. C o m muni t y pl anni ng boards and zoni ng l a ws can and should be used to restrict residential developm ent and other hum an activities from such wetland areas. Towns wi th annoy ance probl em s but wi th l a rge l a nd areas and th i n l y , scat t e red popul at i ons mu st understand that the sam e level of m o squito control achieved in m o re populated com munities will cost them significantly m o re per capita . In m a ny such cases, th e econom i c st atus of th e popul at i on m eans th at i n suffi ci ent t a x dol l a rs can be generat e d t o adequat e l y deal wi th th e probl em .Nantucket provi des an i n t e rest i ng case study . M o squi t o co n tro l h a d lap s ed in th e early eig h ties. Ho wev e r, by 1989 sal t m arsh m o squi t o es were becom i ng a si gni fi cant probl em i n th e west and north areas of th e i s l a nd. The
t o wn began appl y i ng Al t o si d (i ncl udi ng aeri a l appl i cat i ons of pel l e t s i n 1992) t o control th e m o squi t o es whi l e . g e ttin g th e req u i site p e rm its fo r OMW M in sev e ral west -end m a rshes (M adaket , W a rren’s Landi ng Eel Poi n t ) . The OM W M sy st em s were dug i n January 1993 (C hri s t i e 1993). It was hoped th at th e OM W M al one woul d be suffi ci ent t o control m o squi t o es but l a rge-scal e breedi ng cont i nued i n th e north end (Pocom o) and t h e l o w t i d al range has hi ndered th e effect i v eness of th e OM W M as dug. As a resul t , som e l a ri vi ci di ng cont i nues. The concl u si on on Nantucket i s th at m o squi t o control agai nst sa ltm arsh m o sq u ito es mu st b e co n tin u e d at so m e lev e l in order t o provi de resi dent s wi th th e sum m e r envi ronm ent th ey want . However, Nantucket does not t a rget freshwat e r

m o sq u ito es at all an d d o e s n o ad u lticid in g . Nan tu c k e t an d Cap e Co d to g e th er in d i cate th at ad u lticid in g is n o t a requi rem e nt even i n hi gh-t ouri s t areas. It

i s di ffi cul t t o m easure th e i m pact of choosi ng th e no control opt i on. The exam pl e of t o wns th at have l e ft , and l e ft and l a t e r rejoi n ed M C project s i s perhaps th e onl y avai l abl e basi s for est i m at i ng publ i c opi ni on concerni ng such i m pact . No docum ent a t i on of annoy ance l e vel s , cases of di sease, recreat i onal dol l a rs spent , et c., was ever attem p ted in th ese to wn s wh en th ey h a d m o sq u ito co n tro l v e rsu s wh en th ey d i d n o t . Th u s , p u b lic co m p lain ts were apparent l y th e m a i n i ndi cat i on of th e i m pact of th e no control opt i on th at was used i n gui di ng t o wn deci si on

m a ki ng. In th e 1986 quest i onnai r e, onl y about 10% of th e t o wns i n organi zed project s i ndi cat ed th at th ere had been
controversy rel a t i v e t o l eavi ng, joi n i ng, or rejoi n i ng a project . Those th at had experi enced controversy i ndi cat ed
th at 4 fact ors were about equal l y i nvol ved. These were: 1) m onet a ry constr ai nt s, 2) concern over th e effect i v eness of project control program s, 3) concern over th e safet y of th e m e thods used by th e project , and 4) concern over t h e environm ental im pact of the control procedures. Para doxically, 86% of these towns indicated they were unwilling to spend m o re m oney (if legally po ssible) to obtain m o re effective c ontrol and 67% indicated unwillingness to spend m o re m oney to support less hazardous control m e thods . However, the bias of the people filling out the questionnaire sent to each town m a y ha ve influenced these responses; no town in Massachusetts has actually polled th eir citizen s o n th ese q u e stio n s . In fact, so m e to wn s with i n project s have t a ken advant age of new provi si ons whi c h allo w to wn s to co llect ad d itio n a l m o n e y fo r MC activ ities wh ich p r o j ects can th en o n l y sp en d in th ese to wn s.Am ong t o wns th at actual l y wi thdrew from M C program s, m onet a ry constr ai nt s pl ay ed a rol e i n 73% of
th ese deci si ons, fol l o wed by envi ronm ent a l concerns i n 32% and concern over effectiveness in 27% of these cases. Towns th at cont em pl at ed wi thdrawi ng but di d not do so, i ndi cat ed th at m onet a ry and e ffectiveness considerations dom inated their concern. The num ber of t o wns i n M C Ps decl i n ed i n th e l a t e ei ght i e s. Econom i c fact ors, not envi ronm ent a l concerns, were th e dom i n ant reason gi ven for wi thdrawal

. Th is tren d h a s rev e rsed itself sig n i fican tly in th e last several years. The 1990 EEE problem is probably one reason, coupled with the fact th at several coastal program s tr i e d th e no-control opt i on and found m o squi t o num bers rose qui ckl y . M a ny t o wns i n th e B e rkshi r e C ount y and South Shore project s wi thdrew i n 1981 m a i n l y i n response t o Proposition 2-1/2 m onetary cons traints. The rem a ining 8 towns in Be rkshire County subsequently chose to continue as a mu lti-town Project (Note: the town of Lanesborough rejoined in 1986, the city of Pittsfield rejoined in 1988, and other t o wns are cont em pl at i ng reentr y ) . South Shore actual l y di sbanded as a project but by 1988 m o st t o wns had joi n ed nei ghbori ng M C project s i n Norfol k and Pl y m outh C ount i e s. These act i ons suggest th at th ese

co m mu n ities were n o t co n t en t with th e n o co n tro l o p tio n th at resu lted fro m th e d i sb an d i n g o f th eir fo rm er p r o j ect. Towns th at vol unt ari l y wi thdrew from M C project s but th en l a t e r rejoi n ed a project , di d so for a vari et y of reasons. These were i n order of th ei r i m port a nce: i n creased publ i c support for M C , i n creased m o squi t o annoy ance, alleviation of m onetary constraint s, threat of EEE, im proved m e thods and effectiveness of the project. The Environm ental Im pact Statem ent (Sjogren 1977) prepared for the Metr opolitan Mosquito Control District in Min n e so ta attem p ted to q u a n tify th e n o co n tro l o p tio n fo r th eir co m mu n ity. An y attem p t to d e v e lo p sim ilar estim ates for Massachusetts would be m eani ngl ess gi ven th e l ack of appropri a t e basel i n e dat a .B

. B i ol ogi cal C ontrol

. 1. Intr oduct i on B i ol ogi cal control i n cl udes at t acks on th e pest speci es by other speci es and m a ni pul at i on of th e pest speci es i t s el f. The form er i n cl udes th e tr adi t i onal bi ol ogi cal control agent s , predat ors, pathogens and parasi t e s, whereas th e l a t e r i n cl udes such t echni ques as st eri l e -m al e rel ease and genet i c m a ni pul at i ons. B i ol ogi cal control agent s are grouped i n t o th ree cat egori e s: predat ors, parasi t e s and pathogens. Predat ors i n cl ude both vert ebrat e s and i nvert ebrat e s and m a y at t ack bot h ad u lt an d im m a tu re stag es o f m o sq u ito es. Helm in th , protozoan and fungal parasites and m i crobial pathogens genera lly only invade im m a ture stages, though m o rtality

m a y n o t o ccu r u n til th e early ad u lt stag e. Parasitic water m ites are an ex cep tio n in th at th ey attach to certain ad u lts
as th ey em erge from th e pupal st age and apparent l y redu ce adul t survi vorshi p i f th ey are abundant (Lanci ani & B o y e t t 1980) In general , bi ol ogi cal control i s mu ch m o re feasi b l e i n m a nagi ng perm anent wat e r m o squi t o es th an tem porary water form s. Th ere are th ree b a sic strateg i es fo r u tilizin g all b i o l o g i cal co n tro l ag en ts: (1 ) in creasin g ex istin g n a tu ral

enemy popul at i ons by habi t a t al t e rat i on, (2) one-t i m e i n tr oduc t i on of sust ai nabl e exot i c agent s from other regi ons or habi t a t s , and (3) augm ent a t i on of natu ral or exot i c enemy popul at i ons by repeat edl y rel easi ng non-sust ai nabl e, l abreared (or fi el d col l ect ed) organi sm s. To dat e onl y th e fi rst , i n creasi ng fi sh habi t a t th rough OM W M , has been used in Massachusetts. Bti is som e tim es classified as a biologi cal control agent but i t s appl i cat i on t echni que and m ode of
act i on as a st om ach poi son m o re cl osel y resem b l e a pesticide than a biological control agent per se . Ba cillu s sphaeri cus m a y m o re cl osel y fi t th e m odel of repeat edl y rel easi ng non-sust ai nabl e l ab-reared organi sm s as th ere i s evi d ence t o suggest th at i t

recy cl es wi th i n th e envi ronm ent
. No other bi ol ogi cal control agent i s current l y avai l a bl e for general fi el d use, though experi m e nt s cont i nue wi th m a y di fferent organi sm s (see bel o w). There are i m por t a nt reasons why bi ocontrol i s not m o re wi del y used agai nst m o squi t o es. Fi rst , th e di fferences i n bi ol ogy of th e vari ous speci es of m o squi t o es m a ke i t unl i k el y th at any one control agent will operate across a wide range of speci es. Second, m o squito breeding is wide spread, m a king it difficult for a biological control agent to find, or be placed in, all breeding areas. Third, predators such as bats and purpl e m a rt i n s, m a y eat m o squi t o es but prefer t o eat other, l a rger i n sect s. Further, even when abundant , th ey do not dri v e m o squi t o popul at i ons bel o w l e vel s th at peopl e gene ral l y fi nd i n t o l e rabl e. Fi nal l y , th ere i s a hi gh costassociated with sustained releases of a biological control agent and there ar e not, at this tim e, control agents available that require a single, or a fe w, releases to becom e established. Because of the lim ited application of biological control to m o squito es in Massachusetts, the following d i scu ssio n will fo cu s p r im arily o n th e feasib ility o f co n tro l ag en ts cu rren tly b e in g stu d i ed fo r m o sq u ito co n tro l. An im p o r tan t p o i n t to m a k e reg a rd in g b i o l o g i cal co n tro l is th at th e m o sq u ito co n tro l h a v e lim ited research cap ab ilities. W h i l e conduct i ng fi el d eval uat i ons of new control t echni ques i s a desi rabl e pract i ce for any m o squi t o control program , th e project s shoul d not be expect ed t o fi nd and bri ng forward bi ol ogi cal control agent s wi thout subst a nt i a l h e lp fro m research in stitu tio n s su ch as th e state u n i v e rsity. 2. Predators

a. Intr oduct i on In order for any predat or t o i ndependent l y be an effect i v e control agent , i t mu st m eet t w o i m port a nt criteria: (1) its size and abundance in rela tion to the target species mu st be su fficient for it to kill or consum e a high percent a ge of th e prey popul at i on wi th i n a rel a t i v el y s hort t i m e peri od, and (2) i t s feedi ng behavi or shoul d be selective toward the prey speci es when it is present but allo w it to utilize other food item s when the target species is absent . These cri t e ri a are rarel y m e t i n ful l

. Predat ors th at are suffi ci ent l y l a rge and/ or abundant t o have a m a jor i m pact , usual l y l ack feedi ng speci fi ci t y . C onversel y , those wi th feedi ng speci fi ci t y are usual l y l e ss abundant because their populations are re gulated by a m o re restricted food supply. Vertebrate pr edators of insects have a clear size advantage but invert ebrate predators tend to exist in mu ch greater num bers. Because of the lim itations of predators as biocontrol agents, it is norm a lly essential to continuously raise and release the predator to achieve field densities high enough to cause real reductions in the prey species. However, i n som e cases, m a ni pul at i on of th e envi ronm en t t o th e advant age of natu ral predat or popul at i ons can provi de an adequat e augm ent a t i on effect

. b. Vertebrate predators Fish Larvi vorous fi sh are th e ol dest and perhaps m o st effect i v e tr adi t i onal bi ol ogi cal control agent used agai nst

m o squi t o es. In cert a i n habi t a t s th ey m a y , by th em sel v es, provi de adequat e l a rval control th roughout th e breedi ng season. If not , pest i c i d es such as B T I or m e thoprene whi c h are non-t oxi c t o vert ebrat e s can be used i n an i n t e grat ed fash io n with fish

.As al ready m e nt i oned, th e m a i n reason open sal t m arsh m a nagem e nt strat e gi es effect i v el y control m a ny saltm arsh Aedes in the Northeast is because this m e thod provi des access for the abundant estuarine populations of larv iv o r o u s k illifish ( Fundul us spp.) i n t o th e m o squi t o breedi ng pool s i n th e hi gh sal t m arsh (Hruby & M ont gom ery 1986). Th e m o sq u ito fish Ga mb u s ia a ffin is i s di stri but ed wi del y th roughout th e warm er part s of th e worl d and i s th e speci es m o st oft e n reared and i n tr oduced i n t o fresh wat e r habi t a t s for m o squi t o control

. The bi ol ogy and use of
th i s fi sh i n m o squi t o control was revi ewed by M e i s ch (1985). It i s an opportuni st i c feeder and avi d l y eat s pupae and l a t e -i nst a r l a rvae of cul i c i n es and chi r onom i d s. It i s m o st effect i v e agai nst Cu lex i n unveget a t e d, perm anent ponds but has been wi del y used i n C a l i f orni a and th e Gul f St at es agai nst ri cefi e l d Aedes and Psorophora

. Because Gambusia is so aggressive and fecund, it m a y repl ace im portant com m e rcial or rare native fish speci es. Thi s has rai s ed envi ronm ent a l concern over th e i n tr oduct i on of th i s fi sh i n t o natu ral wat e rs where i t does not already occur. A recent article by Rupp (1996) has renewed this debate, both em phasizing real successes and real concerns over Gambusia use (see “C om m e nt s on ‘adverse Assessm ent s of Ga mb u s ia a ffin is ’” (JAM C A 1996) and Boklund 1997, Eliason 1997, a nd Rupp 1997). Because it is not a native sp ecies of Massachusetts it m a y not be im ported and released in state waters. Out s i d e of th e m o squi t o fi sh, th e com m on guppy ( Po ecilia reticu l a t a ) has received the m o st attention for

m o squi t o control (B ay 1985). C o m p arat i v e studi es i ndi cat e th at i t

i s a l e ss effect i v e predat or th an Gam busi abut i t i s m o re t o l e rant of pol l u t e d wat e rs. M a ny other nat i v e fi sh have been expl ored for th ei r m o squi t o control pot ent i a l (B ay 1985). Studi es i n North Afri ca (Al l o et al . 1985) suggest th at m a l a ri a m a y be control l e d th rough th e annual i n tr oduct i on of nat i v e fi sh from stream s i n t o th e m a nm ade wat e r st orage t a nks whi c h produce th e vect or Anophel e s in th is reg i o n . Bird s M a ny bi rds depend on i n sect s as food and those whi c h captu re i n sect s on th e wi ng (e.g., th e swal l o ws), have been credi t e d wi th consum pt i on of si gni fi cant num bers o f m o sq u ito es. Pu rp le m a rtin s sp ecifically h a v e b een prom ot ed on th e basi s of th e cl ai m th at th ey oft e n consum e 10-12 thousand m o squi t o es per day but Kal e (1968) concl uded on th e basi s of exi s t i ng evi d ence th at al l cl ai m s of m a rt i n s si gni fi cant l y reduci ng m o squi t o popul at i ons were unsubstantiated and, because of se veral biological facts, were unlikely to ever be dem onstrated. The facts on which these conclusions were drawn are as follows:(1 ) Mo sq u ito es were a n e g lig ib le item in th e d i et o f m a rtin s in th e o n l y two p u b lish e d stu d i es in which the contents of m a r tin gizzards were exam ined. (2) None of the published statem ents appear ing in the popular ornit hological literature which attrib u t es a m o sq u ito -eatin g h ab it to m a rtin s is b a sed o n factu a l stu d y o rscien tific referen ce. In fact , th ere i s evi d ence th at m a rt i n s feed m o re on l a rger i n sect s i n cl udi ng speci es of dragonfl i e s whi c h m a y be predat ors of adul t m o squi t o es. (3) B e havi or pat t e rns of m o squi t o es and m a rt i n s are such th at th ey t e nd t o not fl y at th e sam e hei ght or at the sam e tim e. Thus, contact between the two is m i nim a l. (4) There i s no evi d ence th at any avi a n speci es can effect i v el y control a pest i n sect upon whi c h i t feeds when th e i n sect i s at or near peak abundance. Other Vertebrates Mosquito control by insectivorous bats was tried in the early part of this centu ry but without success (Kale 1968, Storer 1926). Bats continue to appear in the popul ar press as legitim ate m o s quito-control agents (W right 1996) but are not consi d ered worthwhi l e agent s i n C o m m on-sense Pest C ontrol (Ol kowski et al . 1991), whi c h i s very thorough i n i t s coverage of non-chem i cal control op t i ons, or i n m a i n stream m o squi t o control (M i t c hel l 1992).

c. Invertebrate predators Predat ors of m o squi t o eggs. Evi d ence exi s t s of predat i on on di apausi ng fl ood wat e r m o squi t o eggs by m i t e s and beet l e s, and on Cu lex egg rafts by fish (Collins & W a shino 1985). Nonetheless, egg predation appears to be a relatively m i nor com ponent

o f

n a tu ral m o sq u ito m o rtality an d is n o t b e in g stu d i ed fo r b i o l o g i cal co n tro l. Terrestrial insect and spider predat ors of m o squi t o adul t s Predat i on on em ergi ng and i ndoor rest i ng adul t m o squi t o es has been readi l y observed but th e i m pact of th i s

m o rtality on populations is extrem ely diffi cult to assess. Certain spiders (especi ally Tetragnatha) and predatory flies (m ai nl y Em pi di dae, Anthomy i i d ae and Dol i c hopodi dae) have been shown by preci pi t a t i on t e st s t o have consum ed

em erging m o squitoes (Collins & W a shino 1985). In one Br itish study, up to 28% of the spiders tested had eaten

m o squi t o es (Servi ce 1973). C e rt ai n adul t dragonfl i e s report e dl y captu re m o squi t o es on th e wi ng but th ese observat i ons have not been backed up by any control l e d fi el d studi es. Sy nanthropi c em esi n e bugs (R eduvi i d ae) appears t o be pot ent i a l l y i m port a nt predat ors of i ndoor rest i ng m o squi t o es i n th e tr opi cs. In sum , th e prospect forenhanci ng or m a nagi ng i nvert ebrat e predat ors for m o re eff ectiv e ad u lt co n tro l is n o t en couraging, especially in
tem p erate regions. Aquat i c i n sect predat ors of m o squi t o l a rvae & pupae Aquat i c i n sect predat ors sel dom occur i n si gni fi cant num bers i n th e t e m porary fl oodwat ers th at produce

m o st pest m o squitoes. Studies of predation have therefore largely ta ken place in perm anent ponds or sem i

perm anent habitats such as rice fields, rock pools or ve rnal woodland pools. The adu lt stage of m o st predaceous aquat i c beet l e s and tr ue bugs can fl y (usual l y at ni ght ) so natu ral col oni zat i on of newl y fl ooded habi t a t s can occur i n

a m a tter o f d a ys. Dev e lo p m en t tim e fo r th ese in sects is u s u a lly fro m sev e ral week s to sev e ral m o n th s . Am ong the beetles, the dytiscids (predaceous divi ng beetle), which are predaceous both as larvae and adults, are the m o st effective predator s of m o squitoes. There is evidence fro m studies in rice fields that adult d y tiscid s selectiv ely lo cate an d co lo n i ze sites with lo cally h i g h co n cen tratio n s o f m o sq u ito larv ae (Co llin s & W a shi no 1985). M a ss product i on m e thods for dy t i s ci ds have ne ver been devel oped. W h i r l i g i g beet l e s (Gy r i n i d ae) only feed at the surface where they m a y prey on concentrations of em ergi ng adult m o squitoes. Hydrophilids are onl y predaceous as l a rvae and seem t o feed m a i n l y on chi r onom i d m i dges. Only two aquatic fam ilies of true bugs, the back swim m e r (Notonectidae) and pigmy back swim m e r (Pleidae) have received serious consider ation as m o squito control agents. Pleids are generally not abundant enough
t o have si gni fi cant i m pact but not onect i d s can becom e qui t e dense i n cert a i n habi t a t s . M a ss reari ng of th e l a t t e r appears t o be possi bl e. W a t e r boat m en (Corixidae) are also com m on and si m ilar in appearance to backswim m e rs but th ey are m o st l y detr i tu s feeders. Other predaceous a quat i c Hem i pt era th at have been suggest ed as m o squi t o p r ed ato r s b u t wh ich n o r m a lly o ccu r in in su fficien t d e n s ities to h a v e mu ch v a lu e as n a tu ral co n tro l ag en ts in clu d e th e gi ant wat e r bugs (B el ost o m a t i d ae), wat e r scorpi ons (Nepi d ae), wat e r m easuri ng bugs (Hy d rom e tr i d ae) and th e t w o fam ily o f su rface-feed in g , water strid e rs (Gerrid ae an d Veliid ae). Dragonfl y nai a ds have been m a rket ed com m e rci a l l y for m o squi t o control and at l east one t o wn i n M a ssachuset t s , and others i n New Ham p shi r e and M a i n e, have purchased dragonfl i e s for m o squi t o control

. In northern clim ates these insects require 1-5 years to m a tu re, so th ey n o r m a lly o ccu r in p e rm an en t waters o n l y. Furtherm ore, m a ny are bottom feeders that seldom if ever com e in contact with m o squito species that feed at the surface or in the water colum n . Most bottom -feeding m o squitoes (i.e. Aedes ) occur i n t e m porary wat e r cont ai ni ng few i f any dragonfl y nai a ds. Another fact or wei ghi ng ag ai nst th e m o squi t o control effi ci ency of th ese aquat i cp r ed ato r s is th e fact th at th ey n o r m a lly o ccu r at lo w d e n s ities. Ad u lts o f m a n y sp ecies are territo rial an d th is seem s to spatially lim it population densities of naiads as well as adu lts. In certain habitats such as rice fields, naiads m a y becom e quite abundant but populations fluctuate greatly and their role in lim iti ng populations of rice field

m o squi t o es i s l i m i t e d at best . No control l e d, fi el d studi es have been done i n whi c h na i a ds have perform ed wel l as bi ol ogi cal control agent s . The tr i c hopt eran Li mnephi l u s i ndi vi sus m a y be an i m port a nt predat or of earl y spri ng Aedes i n woodl and

swam ps in Ontario but m o st caddisflie s are om nivorous shredders rather th an predators (Collins & W a shino 1985, Merritt & Cum m i ns 1985). Prospects for m a ss rearing and m a ni pulating caddisfly larvae are not very bright. Many of the aquatic nem a toceran relatives of m o squitoes cont ain groups with predaceous larvae. These include the fam ilies Chaoboridae, Chirom om idae, Ce ratopogonidae, Tipulidae, Anthomyiidae, and others. Most are too sm all
to co n s u m e m a n y m o sq u ito larv ae. Pred atio n o n sm all, early in stars o ccu rs b u t it is far less efficien t in red u c in g th e

num bers of adul t s th an i s predat i on on l a t e i n st ars and pupae. Mochlonyx (C haobori d ) predat i on on spri ng Ae. communi s popul at i ons has been observed i n woodl and pool s i n M a ssachuset t s (Edm ans, personal com muni cat i on) and i n Europe (C hodorowski 1968). The i m pact of th i s sm al l but voraci ous predat or i s unknown. The i n sect predat or wi th th e m o st prom i s e i n m o squi t o control i s another m o squi t o . Larvae of th e nonbi t i ng genus Toxorhychites are l a rge and effect i v e predat ors of m o squi t o es th at devel op i n natu ral and m a n-m a de
cont ai ners such as t i r es, tr ee hol es, m e t a l cans, and l eaf axi s (St e ffan & Evenhui s 1981). Unfortunat e l y , none of th e 7 0 so m e sp ecies in th is m a in ly tro p i cal g e n u s can su rv iv e th e winters as far north as Massachusetts. Their use here woul d th erefore requi re repeat ed, annual rel eases of l ab-rear ed fem a l e s. Thi s i s not warrant ed at th e present t i m e si nce cont ai ner-breedi ng speci es general l y do not represent th e m a jor nui sance or heal th th reat in Massach u s etts. Thi s si tu at i on coul d change i f Ae. al bopi ct us becom e s wel l est abl i s hed i n used t i r es i n th e Northeast

. Focks (1985)
st at es th at al though i t i s possi bl e t o control or reduce cert a i n speci es of cont ai ner-breedi ng m o squi t o es wi th i nocul at i v e or i nundat i v e rel eases of Toxorhynchites , th e useful ness of th i s genus i n pract i cal , operat i onal control program s has y e t t o be dem onstr at ed. Other i nvert ebrat e predat ors of l a rvae and pupae. Am ong th e non-i n sect predat ors of th e i m m a tu re st ages of m o squi t o es, onl y hy dra (C ni dari a: Hy drozoa), fl at worm s (Pl a t y hel m i n th es: Turbel l a ri a) and copopods (C y c l opoi da) have been studi ed i n any det a i l

.B o th hy dra and fl at worm s can be easi l y m a ss produced and, unlike m o st predaceous insects, they can be

m a intained at high densities without cannibalism

. In the la boratory, they kill far m o re larvae than they consum e. B o th groups produce sem i -dorm a nt eggs so th ey occur na tu ral l y i n shal l o w t e m porary pool s as wel l as perm anent

swam ps and ponds. Detrim ental effects on young fish have been reported when these predators are at high densities (M ul l a& Tsai 1978). Both of these predators have good potential as contro l agents in the Northeas t but additional long-term fi el d eval uat i ons are needed. As wi th m o squi t o fi sh, th e l aborat ory product i on, st orage, and fi el d tr ansl ocat i on of
th ese organi sm s requi res a cert a i n degree of sophi st i cat i on, whi c h i s usual l y l acki ng at th e l o cal l e vel

. C u rrent l y , th ere are n o co m m e rcial so u r ces fo r th e q u a n tities th at wo u l d b e req u i red fo r m o sq u ito co n tro l ap p licatio n s . Natural populations of predaceous cyclopoid copepods appear to limit the distribution of container breedi ng m o squi t o es i n cert a i n tr opi cal set t i ngs (M art e n 1984). However, th ey have never been shown t o be i m port a nt predat ors i n t e m p erat e regi ons or i n other t y pes of aquat i c habi t a t s . Therefore t h ei r pot ent i a l for th e bi ol ogi cal control of pest and vect or m o squi t o es i n M a ssachuset t s appears t o be ni l

. 3. Parasi t e s and Pat hogens

a. m e rm ith id n e m a to d e p a rasites Outside of bacteria, parasitic nem a todes are the onl y natural parasites and pathogens that have ever achieved operational status in m o squito control. Known parasitic roundwor m s of m o squitoes now num ber over 20 sp ecies. Th e free-liv in g , aq u a tic, p r ep arasitic stag e wh ich h a tch e s fro m th e n e m a to d e eg g , seek s o u t an d p e n e trates th e cu ticle o f h o s t m o sq u ito larv ae. Larv ae are u s u a lly k illed in th e last in star. In a few sp ecies, th e m a tu re wo rm s are carried over in the adult m o squito and cause m o rt ality when they exit during attem p ted pseudo-oviposition. Romanomermi s cul i c i v orax (i ncl udi ng m o st references t o Reesimermis nfelseni ) is the species that has been m o st ext e nsi v el y studi ed. M e thodol ogi es for th e m a ss product i on and com m e rci a l preparat i on of th i s speci es have been devel oped and i t was bri e fl y m a rket ed as Skeet er Doom i n th e l a t e 1970' g. Low sal e s and probl em s wi th
th e shi ppi ng and shel f-l i f e of vi abl e eggs appear t o have been th e m a jor fact ors whi c h l e d t o th e m a rket i ng fai l u re of
th i s agent (Servi ce 1983). Other econom i c drawbacks i n cl ude host speci fi ci t y whi c h l i m i t s i t s effect i v eness t o onl y certain sp ecies (e.g ., it is in effectiv e in co ld , p o llu ted o rb r ack ish water), an d th e lack o f p a ten t p r o t ectio n fo r

com p anies investing in the production and m a rketing of this product. In add ition, applicators need som e special sk ill an d train i n g to effectiv ely u s e th is b i o c o n tro l ag en t. Th e ten d e n c y o f th is ag en t to n a tu rally recycle o n ce it isi n tr oduced i n t o favorabl e aquat i c habi t a t s i s benefi ci al from a control vi ewpoi nt , but i t

further reduces th e l ong-t e rm

m a rketability and profit potential for pr ivate producers. It rem a ins under study, however, as a recent article ( M i jares et al . 1997) di scussed th e est abl i s hm ent of R. cu licivo r ax in sewage settling ponds and natural ponds in C uba. On th e bi ol ogi cal pl us si de, m e rm i th i d s appear t o be hi ghl y com p at i b l e wi th a wi de range of chem i cal pest i c i d es and growth regul at ors. M o reover, th ey : 1) are non-speci fi c and wel l sui t e d t o th e l i f e cy cl e of th ei r

m o squito host, 2) produce high levels of infection and m o rtality, 3) can be easily m a ss-produced and applied with
st andard spray equi pm ent , and 4) offer no th reat t o non-t a rget organi sm s or th e envi ronm ent
. There are speci es of m e rm i th i d s whi c h appear t o be hi ghl y speci fi c t o spri ng snow-pool Aedes and t o saltm arsh Ae. so llicita n s (Pet ersen 1985). However, th ese worm s have not been est abl i s hed and studi ed i n th e l aborat ory . Such speci es m a y have great er control pot ent i a l in n o r th ern co astal states lik e Massach u s etts th an th e

m o re tro p i cally ad ap ted R. cu licivo r ax . Si nce th e t echnol ogy for usi ng m e rm i th i d s i n m o squi t o control al ready exi s t s , and th ere are num erous fi el d trials d o c u m en tin g th eir co n tro l p o t en tial, th e fu tu re av ailab ility an d u s e o f th ese b i o c o n tro l ag en ts in o p e ratio n a l program s seem s t o depend on changi ng econom i c and m a rket forces (Pet ersen 1985). prot ozoan parasi t e s b. M i crospori d i a Vi rtual l y al l m o squi t o speci es careful l y exam i n ed ha ve been found t o harbor th ese parasi t e s. Larvae are i n fect ed by i ngest i ng th e spore st age. Spores, whi c h are produced at th e end of th e l i f e cy cl e, have oft e n proven di ffi cul t t o i nduce and t o rei n fect l a rvae i n l ab cul tu res. Few m i crospori d i a n l i f e cy cl es are wel l enough known t o assess bi ocontrol pot ent i a l

. Li fe cy cl es vary from si m p l e t o com p l e x and oft e n form th e basi s for th e non-t a xonom i c groupi ng of th ese prot ozoan parasi t e s. The si m p l e st form s (Ty p e I) occur m a i n l y i n t e rrestri al i n sect s and even th e one aquat i c speci es known from m o squi t o es ( N o sema algerae ), d o e s n o t cau se m o rtality u n til, th e ad u lt stag e. Fo r th is reaso n N

. algerae has l i m i t e d pot ent i a l for reduci ng pest probl em s but m a y i m pact on di sease tr ansm i ssi on by reducing survival and fecundity. W ild strains only persist in larval popula tions for short periods and cause little d i rect m o rtality. Typ e II m i cro s p o r id ia h a v e sim p le, asex u al life cycles sim ilar to Typ e I fo rm s an d th ey also sh o w little prom ise in m o squito control (Hazard 1985). Type III form s are dim o rphic, have binucleate spores, and kill

m o sq u ito es in th e larv al st age. Only one species ( Ha za rd ia milleeri ) i s known from m o squi t o es and i t seem s t ohave low infectivity (Hazard 1985). Type IV m i crosporidia include m a ny species from m o squitoes and have the

m o st co n tro l p o t en tial. In fected larv ae are u s u a lly k illed b u t a few fem a les su rv iv e an d carry th e in fectio n v i a th e ovary to the next generation. However, transovarial infection ceases af ter a single generation. Non-ovarian m odes of transm ission mu st exist but this i ssue along with the possibility of sexual reproduction and alternate hosts are as y e t unresol ved. Addi t i onal basi c research i s requi red befo re any m i crospori d i a n can be consi d ered i n th e bi ocontrol of m o squitoes (Hazard 1985). Tet r ahymena and Lambornel l a (tetrah y m e n i d ciliates) Th e lack o f a resistan t restin g stag e an d d i fficu lty in cu ltu rin g th ese ciliated p r o t o z o ah a s p r ev en ted th e thorough study and eval uat i on of th i s group of pot ent i a l bi ocontrol agent s . Ongoi ng studi es of Lambornel l a cl arki in Califo r n i a treeh o l e Ae. sierrensis shoul d hel p t o bet t e r assess th e control val u e of th ese parasi t e s i n th e near futu re (Anderson et al . 1986). Helico s p o r id iu m

There is still debate concerning the proper classifica tion of this spore-form ing group of parasites; som e believe they are prim itive Ascomy cetes f ungi. There are only 3 reports of natura l infections in m o squitoes. They appear t o i n fect a wi de range of speci es but al so m a y i n fect non-t a rget i n sect s as wel l

. Hi gh dosages of spores are requi red t o i n fect ol der i n st ars i n th e l ab. C ont i nuous cul tu res of th ese parasi t e s do not exi s t so th e basi c research needed t o eval uat e th ei r bi ocontrol pot ent i a l i s not forthcom i ng.

c. Fungal Pathogens Coelomomyces M a ny form s of pathogeni c fungi have been known from both l a rval and adul t st ages of m o squi t o es si nce the 1930' s. However, it was not until the discovery of th e obligate alternate host (i.e ., m i crocrustacea) in the m i d70’s th at cul tu res and ful l

- scal e l aborat ory i nvest i g at i ons were possi bl e wi th Coelomomyces (W hi sl er et al . 1974, 1975). The rather com p lex life cycles of som e species have recently been describe d and m e thods for in vivo

cu ltu rin g estab lish e d

. Befo re wid e -scale field ap p licatio n can o ccu r, m a ss in v itro cu ltiv atio n o f th e in fectiv e bi fl agel l a t e zy got e st age needs t o be devel oped. If Coelomomyces , and perhaps th ei r copepod and ostr acod in term ed iate h o s ts, are in tro d u ced in to fav o r ab le h ab itats, th e p o t en tial fo r n a tu ral recyclin g ex ists. Ho wev e r, to o little is known about the host ranges a nd habitat requirem e nt of m o st Coelomomyces to recom m e nd any such i n tr oduct i on at th e present t i m e. M o reover, speci es of Coelomomyces do not rout i n el y provi de hi gh and predi c t abl elev e ls o f m o sq u ito co n tro l. It is, p r em atu r e to critically assess th eir p o t en tial as co n tro l ag en ts to b e u s ed i ndependent l y or as part of an i n t e grat ed control program (Federi c i et al . 1985). Studi es rel a t e d t o th ei r eval uat i on as operational control agents have only recently been initiated and it is not likely that any Coelomomyces will b e

o p e ratio n a l with in th e n ear fu tu re. Lageni di um gi gant eum . Th is m o sq u ito -sp ecific water m o ld is a v e ry p r o m isin g b i o l o g i cal co n tro l ag en t, esp ecially in fresh water and in warm er clim ates. This fungal pathogen can be m a ss produced on artificial m e dia and can recycle in as little as 3 hours (M cC ray 1985). It has a resi st ant , dorm a nt st age and i n fect s a wi de range of m o squi t o speci es. Un fo rtu n a tely, it is n o t effectiv e in p o llu ted , b r ack ish o rco lt waters. Th is lim its its co m m e rcial v a lu e an d it pot ent i a l useful ness i n north ern and coast a l st at es l i k e M a ssachuset t s (Servi ce 1983). Other Fungi Fungi are am ong th e com m onest pathogens of i n sect s and m a ny other genera besi des Coelomomyces and Lageni di um have been report e d from m o squi t o es. Of th ese, Culicinomyces and Met arhi zi um have received the m o st at t e nt i on. B o th groups i n fect a wi de range of m o squi t o speci es but rel a t i v el y hi gh concentr at i ons are requi red t o cause i n fect i on. They can t o l e rat e organi c pol l u t i on and sal i n i t y but not hi gh t e m p eratures (i .e. above 30 ° C). These fungi can be grown on i n expensi v e art i f i c i a l m e di a but no resi st ant rest i ng st age has been fount . Di ffi cul t y i n achi e vi ng l ong t e rm st orage of i n fect i v e st ages and formul at i on probl em s rem a i n as barri ers t o com m e rci a l product i on. Noneth el ess, th ese fungi are a prom i s i ng group of bi ocontrol agent s whi c h m a y provi de new m o squi t o

co n tro l to o l s in th e fu tu re. Eryni a aquat i c a Eryni a aquat i c a i s an Ent o m ophthoral es fungus, and i s th e onl y speci es of th e genus known t o i n fect th e im m a tu re aq u a tic stag es o f m o sq u ito es . It was fi rst di scovered i n fect i ng Ae. canadensi s and Cs. moristans larv ae in woodl and pool s i n Hart ford C ount y , C onnect i c ut from l a t e M a y t o earl y June (Anderson & R i ngo 1969). It has since been recovered in early May from Ae. st i m ul ans in woodland pools near the villa ge of Cam b ridge, New York (M ol l o y & W r ai ght 1982) and from Ae. cant at or on M a y 21, 1981 i n a shal l o w sal t m eadow pool i n M i l f ord, Connecticut (Andreadis & Magnarelli 1983). Most recen tly, is was discovered in 1995 and 1996 in a woodland pool i n B r i s t o l , R hode Isl a nd (C hri s t i e 1997).St ei nkraus and Kram er (1989) col l ect ed Ae. fitch ii larvae infected with E. aquat i c a f r o m as e mi

- p e r ma n e n t woodland pool in Tom pkins C ounty, New York. They used infected pup ae to successfully tran sm it the disease to

em ergi ng adul t Ae. aegypt i , on whi c h rest i ng spores of th e fungus devel oped. Eryni a aquat i c a h a s ch aracteristics wh ich m a k e it attractiv e as a m i crobial agent: it is capable of causing epi z oot i c s, has been found i n both freshwat e r and bracki s h wa t e r m o squi t o es and has a rest i ng spore st age th at m a y survi v e wel l i n st orage. Operat i ng agai nst i t

i s th e fact th at i t

has onl y been found i n cool er, spri ngt i m e wat e rs. One thought is that infected pupae m a y be rem oved from the origin al infestation site and placedin other, nearby pools. A fungus that kills in the pupal st age works against its own spread. d. B act eri a l pathogens Ba cillu s th u r in g i en sis var. israelensis B t i Serot y pe H-14 has becom e an i m port a nt bi ol ogi cal larv icid e fo llo win g its d i sco v e ry in th e Neg e v d e sert i n 1976. W i th i n th e l a st 5 y ears i t has becom e wi del y used by th e m o squi t o control project s i n M a ssachuset t s . It i s now the larvicide of choice in m a ny s ituations because of its host specific ity, high and rapid m o rtality to m a ny

m o squi t o es speci es, and i t s envi ronm ent a l safet y . It i s qui t e di st i n ct from th e B t strai n s whi c h i n fect l e pi dopt erous in sects. Its track reco rd in co n tro llin g p o llu ted

- water Cu lex is m i xed, apparently because it sinks to the bottom and
th e act i v e m o i e t y rapi dl y bi nds t o organi c part i c ul at es. C onsequent l y , hi gher dosages are requi red t o achi e ve good
control i n hi ghl y organi c and deep-wat er si tu at i on. Sal t m ar sh m o squi t o es general l y requi re rat e s at th e hi gh end of
th e l abel e d appl i cat i on rat e s for effect control

. Li qui d, powder, granul ar and sl ow-rel ease bri quet formul at i ons are

co m m e rcially av ailab l e. Bti mu st be ingested to cause toxicity to filter-feeding m o squito larv ae; pathology occurs in cells of the

m i dgut wall. It is least toxic to 4th instars since they cease feeding at least 12 hours prior to pupation. The

m o squi t o t oxi c i ngredi e nt of B t i preparat i ons i s th e heat l abi l e del t aent o t oxi n l o cat ed i n th e prot ei naceous parasporal crystallin e in clu s io n s syn th e sized co n c o m itan tly with th e sp o r e d u r in g sp o r o g e n e sis. On ce released in th e envi ronm ent , i t bi odegrades rapi dl y (i t i s usual l y onl y act i v e 1-3 day s ) and th i s bact eri u m (gram negat i v e Bacillaceae) does not recycle. This is considered the only m a jor drawback of this highly effective m o squito pathogen but it has enhanced its co m m e rcialization (Lacey & Undeen 1986). Th e b i o c id al activ ity o f Bti to x i n ap p ears to b e lim ited to larv ae o f certain fam ilies o f n e m a to cero u s Di pt era. A l a rge num ber of l aborat ory and fi el d t e st s have confi r m e d th at al l non-nem a t o cerous, non-t a rgetorgani sm s are vi rtual l y unaffect ed (Lacy 1985). Al l exi s t i ng dat ai ndi cat e th at th e unal t e red prot oxi n of B t i i s al so safe to vertebrates including hum ans (Lacey 1985). Further im provem e nts in the efficacy and price com p etitiveness of th i s control agent , brought about by formul at i on changes and genet i c engi neeri ng, are l i k el y t o occur i n th e near fu tu re. In ad d itio n , fo rmu l atio n o f th is ag en t with o th e r co m p atib le an d p e rh ap s syn e rg istic ag en ts su ch as j u v e n ile horm one anal ogs (e.g. Al t o si d) i s current l y underway . Su ch m i xture have t w o i m port a nt advant ages. They reduce
th e l i k el i hood of m o squi t o es devel opi ng resi st ance t o ei th er agent and, secondl y , th ey wi den th e wi ndow for control since Bti is m o st effective agai nst earl y i n st ars and growth regul at ors agai nst l a t e r i n st ars. Bacillus sphaericus

. Although only recently available, B. sphaeri cus m a y have greater control poten tial than Bti because of its ability to continue to recycle once it is in troduced. It has m a ny of the sam e benefi cial attributes of Bti but all strains isolated to date are less effective against a wide range of sp ecies th an is Bti. At th e m o m e n t it is p r im arily m a rk eted against Culex i n hi gh-organi c wat e rs but research i s on-goi ng i n expandi ng i t s control pot ent i a l

.
e. Vi ral Pathogens The bi ol ogi cal control pot ent i a l of both non-accluted (i ri dovi ruses and densonucl e osi s vi ruses) and occl udet (bacul ovi ruses, cy t opl asm i c pol y h edrosi s vi ruses and ent o m opox vi ruses) vi ruses pathogeni c t o

m o squitoes has recently been reviewed by Federicci (1985). It is sufficient here to sim p ly paraphrase from the

sum m a ry of th i s thorough revi ew as fol l o ws: Anal y s i s of research conduct e d t o dat e m a kes i t cl ear th at none of th e vi ral pathogens of m o squi t o es can current l y be consi d ered good candi dat e s for m o squi t o m a nagem e nt program s. The t w o m a i n reasons for th i s

assessm en t are th at v i ru ses d i sco v e red so far p o ssess lo w in fectiv ity fo r o r ig in al o raltern ate h o s ts an d th ere is n o readi l y avai l abl e m e thod for m a ss product i on of vi ri ons. Thi s apparent l ack of control pot ent i a l i s m o st obvi ous when one consi d ers th at few fi el d tr ai l s have been conduct e d wi th th ese agent s even though th e fi rst one was d i sco v e red o v e r 1 5 years ag o . W h ile it ap p ears u n lik ely th at v i ru ses will b e d e v e lo p e d fo r m o sq u ito co n tro l in th e near future, they m a y prove to be ex trem ely useful m i crobial agents in th e long term , perhaps in 2 or 3 decades, once we l earn how t o m a ni pul at e th em effect i v el y . B i ot echnol ogy has th e great est pot ent i a l for engi neeri ng new

m o re useful biocontrol organism s am ong the viruses because of thei r sim p le m o lecular structure. 4. Pest Speci es M a ni pul at i onA som e what di fferent approach t o bi ol ogi cal control i s m a ni pul at i on of th e m o squi t o genom e t o ei th er 1) i nduce reproduct i v e fai l u re (l eadi ng t o popul at i on el i m i n at i on) or 2) bri ng about perm anent changes i n th e behavi or or phy si ol ogy of th e t a rget popul at i on so i t no l onger vect ors di sease or bi t e s peopl e. There are num erous theoretical m echanism s by which this could be accom p lished. Following is a brief discussion of the three approaches that have been m o st com m onl y di scussed and researched.

a. Sterile Insect Technique The early and continuing success of the sterile m a le release p r o g r am in elim in atin g th e screwwo rm fly from th e U.S. and M e xi co has gi ven ri se t o m a ny i nve st i g at i ons and new i d eas for control l i ng other i n sect s (i nocul at i ng m o squi t o es) th rough th e use of th i s or som e other genet i c t echni que. Except for frui t fl i e s, th i s m e thod has not y e t been successful l y appl i e d t o other i n sect s i n operat i onal program s and th e t echni que i s not current l y bei ng pursued for m o squi t o control

. b

. In co m p atib ility In co m p atib ility resu ltin g fro m a lack o f fertility in sex u a l u n i o n s m a y o ccu r d u e to a v a riety o f g e n o m ic failures or due to the effort of bact eria-like sym b ionts to control the repr oduction of host (Barr 1985). The feasibility of suppressi ng Cu lex pi pi ens through cytoplasm i c incom p atibility was de m onstrated in a Burm ese Village over 20 years ago (Laven 1967) but the practicality of this m e t hod has not been confirm e d by any other field tests. Mo reo v e r, in co m p atib ility facto r s h a v e b een iso l ated in o n l y a few m o sq u ito sp ecies to d a te.

c. Chrom o som a l Aberrations There are several heritable chrom o som e rearrangem e nts th at can, in theory, be used to in j ect g e n e tic lo ad i n t o a m o squi t o popul at i on and/ or t o effect a perm anen t change i n th e genet i c m a keup of th e popul at i on. These aberrations can be used to 1) increase genetic lethal load (serility is lim ited to 50-80% because of the low chrom o som e num ber (three, in m o st m o squitoes) or 2) re place noxious species with harm less strains if appropriate vi abl e hom ozy gous rearrangem e nt s are avai l abl e. The l a t t e r i s perhaps onl y appl i cabl e i n th e case of i m port a nt di sease vect ors. Natu ral l y occurri ng aberrat i ons can be screened for i n wi l d popul at i ons but th ei r frequency i s great l y i n creased th rough exposure t o mu t a gens. C ontrol l i ng m o squi t o es th rough th e use of chrom o som a l aberrat i ons requi res a m a jor basi c research effort and a target species that is easily colonized. This later req u i rem e n t au to m a tically elim in ates m a n y im p o r tan t sp ecies from consi d erat i on.d. Com p etitive Displacem ent The fi nal , and som e what abstract , strat e gy for control l i ng m o squi t o es bi ol ogi cal l y i s th e ecol ogi cal l y based notion of displacing a noxious species by introducing a beni gn but m o re com p etitive (i.e. better adapted) exotic one. Thi s i d ea has been suggest ed pri m ari l y t o control cont ai ner-breedi ng speci es l i k e Ae. aegypt i . However, beni gn m o squi t o speci es are di ffi cul t t o fi nd, as m o st m o squi t o es th at have becom e est abl i s hed ( Ae. aegypt i , Ae. al bopi ct us ) are as bad or worse than the species w ith wh ich th ey co m p et e (cont ai ner-breedi ng Cu lex and Ae. triseria tu s ). 5. Other C ontrol Approaches

a. Trap out t echni ques. Al l experi ence t o dat e i ndi cat es th at whi l e vari ous tr aps m a y be good sam p l i ng devi ces for adul t m o squi t o es, th ey are t oo i n e ffi ci ent and l i m i t e d i n th ei r range t o provi de any benefi t i n reduci ng bi t i ng annoy ances (Nasci et al . 1983). W o rk i s ongoi ng on at tr act ant s (oct anol ) th at woul d both great l y i n crease tr ap col l ect i ons of m o squi t o es and reduce non-t a rget s tr apped, but no product s are m a rket ed for th i s purpose t o dat e . Electrocutor traps (“Bug Zappers”) continue to be a popular item , with an estim ated 1.75 m illion sold in the United States each year (Mitchell 1992) but they are extrem ely non-specifi c (m osquitoes generally m a ke up less
th an 5% of th e cat ch, and m a y be harm ful t o other i n s ect speci es. They cannot be consi d ered a part of any

m o squi t o -control program . b. R e pel l e nt s. Personal prot ect i on th rough th e use of m o squi t o repel l e nt s i s an appropri a t e al t e rnat i v e t o control l i ng th e m o squi t o popul at i ons before th ey bi t e . Thi s i s especi al l y tr ue i f th e peri ods of annoy ance are i n frequent and bri e f and where th e l a nd areas are t oo vast and unpopul at ed t o econom i cal l y consi d er control program s. The m o st com m only used m o squito repellent is DEET (N,N)(diethyl-m etatoluam i de) which has been formul at ed and sol d under a vari et y of tr ade nam e s (e.g., Off, M u skol , C u t t e rs), i n a vari et y of concentr at i ons and as both aerosol spray s (usual l y ca 15%) and l o t i ons (up t o 100%). Laborat ory t e st s have shown th at m a xi mu m repel l e nt durat i on (ca. 1-2 hours) i s obt ai ned wi th a concen tr at i on of ca. 50% so th at hi gher concentr at i ons do not provide appreciable advantages. The m a jor disadvantage o£ DEET are: 1) rel a t i v el y short prot ect i on t i m e 2) som e what offensi v e odor3) dam a ge to som e fabrics and surfaces at higher concentrations 4) hi gh cost 5) possible hazards from heavy use Sm all children frequently have skin reactions to D EET. Sm all children are also m o st likely to be the individuals that develop m e urotixic ological sym p tom s from DEET. Thirt een of 14 cases of encephalopathy (toxicity of the central nervous syst em ), found in publicly available reports by a recent review (Osim itz and Grothaus 1995), were i n chi l d ren 8 y ears ol d or y ounger. Three of th ese chi l d ren di ed, al l havi ng used “heavy ”

am ounts of repellent, even though the repellent in each cas e had DEET concentrations of 20% or less. Oral i ngest i on m a y have pl ay ed a rol e i n som e of th e cases. Osi m i t z and Grothaus (1995) concl uded th at th ere i s no evidence that increased DEET concentration has an effect of the sever ity of sym p tom s . They also com p ared reports that the Poison Control Center received for DEET (6,724 in children under 6 years old dur ing a five-year period) to laundry detergent reports (10,789 in 1989) and househol d bleach (16,169 in 1989), c oncluding that accidental exposure, whi l e undesi rabl y hi gh, i s i n l i n e wi th , or l o wer th an, exposure t o other househol d chem i cal s. There is one unsubstantiated report in the Russian literature of carcinoge nic effects in rats at high doses. Three other repel l e nt m a t e ri al s are i n com m on use. Di m e th y l phthal a t e (general l y sol d as 6-12) i s not as effective as DEET against m o squitoes but still has a share of the m a rket. Citr onella-based repellents have long been

m a rket ed as candl es or i n oi l

- burni ng l a m p s. C i tr onel l ai s al so avai l abl e as a repel l e nt t o be spray e d i n ski n and cl othi ng (Natrapel ) . The th i r d m a t e ri al (Avon ski n -so-soft ) i s a popul ar bath oi l th at i s not m a rket ed as a m o squi t o repel l e nt but has, th rough word of m outh, been recogni zed fo r i t s as y e t uncharact eri zed m o squi t o repel l e nt affect

. It is as effective as DEET but it does not persist as long. On the other hand, it is mu ch cheaper, sm ells better, and apparently does not dam a ge any fabrics or surfaces. The activ e ingredient(s) of skin-so-soft has not been isolated or identified to date. It also has not unde rgone the EPA safety testing that other repellents have because it is m a rketed as a beauty aid rather than a pe sticide (Note: repellents are cla ssified as pesticides by EPA). El ectroni c m o squi t o repel l e nt devi ces whi c h are peri odi cal l y m a rket ed i n th e U.S. (usual l y by m a i l order houses) are com p l e t e l y i n effect i v e and are not based on any bi ol ogi cal rat i onal e (Fost e r & Lut e s 1985, M i t c hel l 1992, C u rt i s 1994). C. Physical Control 1. Ty pes of Habi t a t M odi fi cat i ona. Open m a rsh wat e r m a nagem e nt (OM W M ) Ori g i n al l y devel oped for New Jersey sal t m a rshe s (Ferri gno 1970, Ferri gno & Jobbi ns 1968, Ferri gno et al

. 1969), th i s strat e gy basi cal l y at t e m p t s t o overcom e th e l i mi t a t i ons of di t c hi ng by th e i n corporat i on of other wat e r

m a nagem e nt strat e gi es. In part i c ul ar, cham pai gn pool s or reservoi rs (whi ch perm anent l y hol d wat e r and sust ai n l a rvi vorous fi sh) are creat ed (by backhoe, dragl i n e or rot a ry di t c her) i n sel ect ed t i d al pool s or l a rge shal l o w pans and are connect ed vi a sm al l shal l o w di t c hes t o surroundi ng m o squi t o breedi ng depressi ons. If ol d di t c hes are redug and used as reservoi rs, th en pl ugs mu st be i n sert ed at th e t i d al end t o prevent drai nage. Thi s cust om i zed approach t o m a rsh m a nagem e nt represent s th e l east del e t e ri ous and m o st effi ci ent nonpest i c i d al m e thod for
control l i ng sal t m arsh m o squi t o es and has been adapt e d t o New Engl and condi t i ons (B oy es and C a pot ost o 1980, Hruby et al. 1985, Christie 1990). A m a nual outlining this m e thod was de veloped by the Massachusetts Audubon Soci et y (Hruby and M ont gom ery 1986) and OM W M i s current l y bei ng pract i ced by coast a l project s i n Essex and Plym outh Counties in Massachusetts. As of 1996, OMW M had becom e the accepted technique for new salt-m a rsh wat e r m a nagem e nt work, though m a i n t e nance work rem a i n s dom i n at ed by cl eani ng exi s t i ng di t c hi ng, as opposed t o conversi on t o OM W M

. b. Other M odi fi cat i on Strat e gi es M o squito control efforts in M a ssac husetts predate m odern chem ical in secticides. Early control efforts consi s t e d of source reduct i on work, m o st l y i n sal t m a rshe s (see “Hi s t o ry of C a pe C od M o squi t o C ontrol Project , 1928-1971”). Thi s em phasi s was l a rgel y abandoned when ch eap and seem i ngl y m o re effect i v e organo-chl o ri ne insecticides becam e availabl e in the early 1950' s. Early control progr am s capitalized on cheap W P A labor but they failed to ach iev e th e lev e l o f co n tro l th at th e p u b lic h a s co m e t o expect of m odern control program s. Noneth el ess, they serve as a rem i nder that m o squito control, from its earliest in cep tio n , co n s id ered and practiced control altern ativ es to syn th e tic ch em ical p e sticid es. Except for new OM W M project s i n sal t m a rshes, m o squi t o control source reduct i on work now consi s t s p r im arily o f m a in ten a n ce wo rk o n ex istin g cu lv erts, sto r m sewers an d d itch e s. Very little n e w d itch co n s tru c tio n has taken place in recent years. Ditch cleaning, which often involve s excavating spoil with a backhoe or plow, is an activity which has drawn great concern wh en it takes place in estuarine environm en ts. This is because m a ny of the ol d gri d di t c hes i n th e sal t m arsh served no real purpose for m o squi t o control but th ey mu st be re-cl eaned periodically or they them selves becom e sha llow breeding areas for saltm arsh m o squitoes.c. Ori g i n at i on of R e quest s for Phy s i cal C ontrol

. The exem pt i on from cert a i n regul at i ons enjoy e d by m o squi t o control i s a t w o-edged sword. On th e one hand, i t enabl e s m o squi t o control project s t o m o re qui ckl y respond t o drai nage probl em s. On th e other hand, i t

m a kes th e headi ng “M osqui t o C ontrol ” part i c ul arl y desi rabl e for drai nage project s i n whi c h m o squi t o control i s , at best , a m a rgi n al goal

. Thi s pressure can com e from propert y owners, publ i c offi ci al s, or from wi th i n control project s th em sel v es. The pressure t o conduct drai nage wo rk th at does not have a m o squi t o -control com ponent mu st be resisted. The best i n t e rest s of m o squi t o control program s are se rved by conservat i v e appl i cat i on of th e defi ni t i on of

m o squi t o control , as over-use of th e wet l a nds exem pt i ons m a y resul t i n th e l o ss of those exem pt i ons. To th i s end,

m o squi t o control program s, i n conjunct i on wi th st at e a nd federal wet l a nds prot ect i on agenci es, mu st devel op a strong set of gui del i n es for al t e rat i ons exem pt

from W e t l a nds Prot ect i on Act

. 2. Ecosy s t e m changes of non-t a rget bi ot a as a resul t of phy si cal control s .
a. Salt Marsh

. New Engl and coast a l wet l a nds have been heavi l y i m pact ed by m a n (Shi sl er 1990). However, evi d ence

co n cern i n g th e n e g a tiv e im p act o f saltm arsh d itch m a in ten a n ce activ ity is m i x e d

. Th e p r in cip a l co n cern is with di sposal of th e spoi l on th e m a rsh and th e i nvasi on of upl and pl ant s th at can occur wi th even sl i ght el evat i on increases (i.e. 1-2 inches) (Miller and Egle r 1950, Buchsbaum 1994). Ditching also perm its Spartina alterniflora to i nvade th e upper m a rsh (dom i n at ed by Spart i na pat ens and Distich lis sp ica t a ) al ong th e edges of th e newl y creat ed di t c hes. There i s evi d ence t o support th e cl ai m th at th i s i n creases m a rsh product i v i t y (B uchsbaum 1994). In 1979, st aff bi ol ogi st s from th e New Engl and Di vi si on of th e U.S. Army C o rps of Engi neers (DeSi s t a& Newl i ng 1979) carri ed out prel i m i n ary i nvest i g at i on i n seve ral M a ssachuset t s sal t m a rshes t o expl ore th e i ssue of spoil deposition and upland plan t invasion. In m a ny instances they f ound little plant invasion despite evidence of previ ous spoi l deposi t i on of 2 i n ches or m o re i n depth o n th e m a rsh

. In a few lo catio n s with m i n i m a l tid al i n fl uence, som e i nvasi on by sp ecies such as com m on ragweed ( Amb ro s ia a r temisifu lia ), m a rch elder ( Iva frutescens ), and seasi d e gol denrod ( Sol i dago semprevi rens ) had occurred over t i m e. However, t h ey concl uded th at i t

was not obvi ousl y correl a t e d wi th th e spoi l i t s el f but was perhaps caused by som e other fact or associ at ed wi th th e di sturbance t o th e m a rsh. They recom m e nded th e sort of l ong-t e rm m oni t o ri ng studi es whi c h have as y e t not been carried o u t in Massach u s etts salt m a rsh e s.C l arke et al . (1984) studi ed th e effect of di t c hi ng and veget a t i on changes on th e use of th e sal t m arsh by bi rds i n R o wl ey , M a ssachuset t s . They concl uded t h at bi rduse of th e m a rsh was negat i v el y i m pact ed by m o squi t o control di t c hi ng. Thi s i s i n contrast t o th e studi es of Shi s l e r & Jobbi ns (1977) i n New Jersey m a rshes where i n crease product i v i t y was observed i n di t c hed m a rshes. Dai b er (1986) not ed th at , where di t c hes drai n pannes, bi rds that need a constant water supply (Am e rican bittern, pied-billed grebe and Am eri can coot) m a y decline. Also noted was a case where spoi l ri dges i nvade by Bacchari s and Iva caused gul l s t o seek l e ss brushy areas for nest i ng. Schei r er (1994) encouraged m o squi t o control program s t o devel op wat e r m a nagem e nt part nershi ps wi th th e U. S. Fish and W ildlife Service, especially for OM W M -t y p e m a rsh rest orat i ons desi gned t o i m prove m i grant wat e rfowl h ab itat. In a seri es of i nvest i g at i v e report s by st aff bi ol o g i sts fro m th e Natio n a l Park Serv ice, th e en v i ro n m en tal i m pact of di t c hi ng and di ki ng of sal t m a rshes i n th e Herri ng R i ver basi n of C a pe C od Nat i onal Seashore were i nvest i g at ed (Soukup & Port noy 1983, Port noy 1984a, 1984b). These report s hel d th at C a pe C od m a rsh

m a nagem e nt pract i ces were responsi b l e for th e fresheni ng, st agnat i on, aci di fi cat i on and hi gh sul f at e and al um i num concentr at i on i n di ked m a rshes. These authors suggest th at th e destruct i on of a th ri vi ng eel and herri ng fi shery i n W e l l f l eet was th e di rect resul t of th ese m a rsh di srupt i ons. However, th e m a i n di ke across th e m outh of th e Herri ng Ri ver (from Gri ffi n Isl a nd t o th e M a i n l a nd) was constr uct e d i n 1909 wi th th e m a i n object i v e of provi di ng for agricultural use of the basin. These structures are not t y pi cal of earl y m o squi t o m a rsh m a nagem e nt pract i ces i n other coast a l regi ons i n M a ssachuset t s . The i m pact m a y be l a rgel y reversi b l e i f di kes are rem oved and norm a l t i d al flo w is allo wed to retu rn to th ese areas. OMW M tailo red to th e u n i q u e ch aracteristics o f th ese sm all estu aries shoul d be expl ored as a way t o m a nage th e Ae. so llicita n s populations which are likely to replace the present Ae.
cant at or popul at i ons i f t i d al fl ow and norm a l veget a t i on and sal i n i t y are rest ored i n th ese m a rshes. Perhaps th e m o st dam a gi ng assessm ent of di t c hi ng i n sal t m a rshes was th e report of B ourn and C o t t a m (1950) i n whi c h th ey bl am ed open di t c hi ng for convert i ng up t o 90% of th e Spartina alterniflora m a rsh al ong th e Misp illio n Riv e r in Delaware to Bacchari s . However, Provost (1977) report e d th at th e area had retu rned t o Sp.

a ltern iflo ra after navigational dredging of the river had ceased and concluded that it was the dredging of the m a in ch an n e l, n o t th e m a rsh d itch i n g , wh ich h a d p e rm itted Bacchari s t o i nvade th e m a rsh (see Dai b er 1986 and B u chsbaum 1994 for revi ews of th i s debat e ). Argui ng agai nst si gni fi cant wat e r-t abl e l o weri ng i n sal t m a rshes i s th estrong affinity for water exhi bited by salt m a rsh soils. Because perm eab ility is so low, the water table m a y be l o wered onl y wi th i n a m e t e r or so of th e di t c h i t s el f (B al l i ng and R e sh 1982). Grid d itch i n g , ev en if n o t th e m a rsh d e stro yer so m e claim it to b e , still red u ces stan d i n g water o n th e m a rsh and creat es an unnatu ral and aesth et i cal l y unpl easi ng vi ew. Open m a rsh wat e r m a nagem e nt was desi gned t o m o re clo s ely ap p r o x i m a te th e d i v e rsity o f th e n a tu ral m a rsh wh ile elim in atin g th e sh allo w p a n n e s in wh ich m o sq u ito es breed. W o l f e (1996) revi ewed t h e effect s of OM W M on num erous t i d al m a rsh resources. OM W M sy st em s t e nded t o enhance t i d al exchange and sal i n i t y i n m a rshes th at were convert ed from gri d di t c hi ng. Except where spoi l pi l e s were l e ft (i m p roperl y ) on th e m a rsh, veget a t i on change was sl i ght and favored salt-m a rsh species such as Spart i na pat ens and Distich lis sp ica t a . Sm all ch an g e s in elev atio n d u e to sp o il d e p o s itio n so m e tim es resu lt in i nvasi on by Iva, Bacchari s , and Phragmi t e s . Salt-m a rsh sn ails ( Mel ampus bi dent at us ) have decl i n ed i n som e OM W M si t e s but not i n others. Si m i l a r m i xed obs ervat i ons have been m a de for m a rsh peri wi nkl e ( Litto rin a irrorata) and fiddler crabs ( Uca speci es). M a rsh fi sh popul at i ons are, by desi gn, enhanced by OM W M . However, changes i n speci es com posi t i on m a y occur wher e exi s t i ng pool s are deepened. M u m m i chogs ( Fundul us h e tero clitu s )an d sp o t fin k illifish ( Fundul us l u ci ae ) shoul d decrease whi l e sheepshead m i nnows ( C y pri nodon vari egat us ), in lan d silv ersid e s ( Men id ia men i d i a ) an d rain water k illifish ( Lucani a parva ) shoul d i n crease (Tal bot et al . 1986). The sm al l reservoi rs are not part i c ul arl y at tr act i v e t o bi rds and th e m i nor changes i n hy drol ogy , fl ora and i nvert ebrat e fauna caused by OM W M do not cause si gni fi cant changes i n bi rd use on OM W M si t e s. Effect s on

m a m m a ls are not well docum ented. OMW M has had no long-te rm detrim ental effects on water quality. As a result, W o l f concl udes th at , “Open M a rsh W a t e r M a nagem e nt i s an envi ronm ent a l l y focused m a nagem e nt t ool th at i s desi gned t o be com p at i b l e wi th natu re rath er th an com p et e wi th i t
. ” Of course, th e t echni que i s new enough th at l ong-t e rm m oni t o ri ng i s requi red t o ensure th at al t e red si t e s rem a i n funct i onal sal t m a rshes. b. Freshwat er W e t l a nds (excl u si ve of Vernal Pool s). Pal u stri ne wet l a nds, i n cl udi ng

em ergent , scrub-shrub and forest ed wet l a nds, are th e dom i n an t system in wh ich Massach u s etts fresh water p h y sical control take place. In the vast m a jority of cases, this work consists of m a intaini ng existing ditching designed to

rem ove st andi ng wat e r from th e wet l a nd, th ereby reduci ng m o s q u ito -b reed in g h ab itat. Fo r m o st MCPs, th is typ e o f work (source reduct i on) m a kes up a l a rge percent a ge of th ei r control effort . Though reduci ng st andi ng wat e r certain ly red u ces m o sq u ito b r eed in g , th ere h a s b een little research co n cern i n g th e o v e rall effects o f th ese alteratio n son th e m odi fi ed wet l a nd. Di t c h sy st em s can becom e probl em s i n th ei r own ri ght , produci ng m o squi t o es i f l e ft

unm ai nt ai ned. M o st of th ese sy st em s were never desi gned speci fi cal l y for m o squi t o control and th ei r other, pri m ary funct i on, such as rem ovi ng runoff from l a rge parki ng l o t s , m a y cause consi d erabl e dam a ge t o th e ecosy st em , leaving the MCP to clean up, or at l east deal with, som e one else’s m e ss. Th e m a j o rity o f d r ain a g e system s cu rren tly m a in tain ed b y MCPs were n o t in itially co n s tru c ted b y MCPs and th e effort of M C Ps t oday i s al m o st ent i r el y restri ct ed t o rem ovi ng bl ockages t o exi s t i ng fl ows, rath er th an enl a rgi ng or strai ght eni ng channel s t o i n crease fl ow. M o st freshwat e r drai nage i s an i nheri t e d probl em whi c h requires intervention not because of m o squito-control activities but because of the activities of others. Road sand and y a rd wast er represent t w o of th e m o st com m on obs tr uct i ons M C Ps are cal l e d upon t o rem ove from exi s t i ng stream s and drai nage net w orks. New devel opm ent s al so can cause dram atic changes in th e sed i m e n t lo ad in
stream s, despi t e regul at i ons desi gned t o prevent such probl em s. Road sand, yard waste and increased sedim e nt load from developm ent can all have im pacts on a stream that are as greater or greater than re gul ar di t c h m a i n t e nance. Because MCPs are often involve d in rem oving m a nm ade sedim e nt s from stream s, a system under appropri a t e di t c h m a i n t e nance m a y funct i on m o re cl osel y t o a natu ral sy st em th an one i n whi c h m a nm ade wast es are allowed to accumu late unabated. The appropriate re sponse by the MCP in such cases is not obvious because, al though th e probl em , and i t s cause, m a y not be m o squi t o rel a t e d, th e m o squi t o control program m a y be th e organi zat i on best equi pped, both from a nd equi pm ent and a tr ai ni ng perspect i v e, t o rect i f y th e si tu at i on. Si nce m o squi t o control project s cam e i n t o bei ng i n M a ssachuset t s , th e percei ved val u es of wet l a nds have changed. Once shunned as disease-bear ing waste lands, best suited for dum pi ng, draining or filling, wetlands are

n o w v i ewed in a mu ch m o re p o s itiv e way. Th ey are im p o r tan t wild life h ab itats, p e rfo rm a my riad o f water q u a lity

m a i n t e nance funct i ons, and serve as fl ood control , eros i on, ground-wat e r recharge and wat e r suppl y regul at ors (Tiner 1989). Mosquito control program s have been slow in adapting to the increased value accorded wetlands. On
th e one hand, l ong-resi dual and/ or broad-spectrum pest i c i d es are no l onger used i n wet l a nds i n M a ssachuset t s . On th e other hand, th ere i s real resi st ance t o hal t i ng m a i n t e na nce work i n drai nage net w orks th at m a y be seri ousl y dam a gi ng wet l a nd habi t a t
. There has not been a great deal of work done speci fi cal l y on th e effect s of phy si cal control for m o squi t o es on non-t a rget organi sm s. Therefore th e fol l o wi ng di scussi on i s based on th e general effect s th at can be expect ed when wet l a nd al t e rat i ons are m a de. C a re shoul d be t a ken i n ext e ndi ng th ese general concerns t o m o squi t o controlin Massach u s etts. Fo r ex am p l e, ch an n e lizatio n (straig h t en in g ) o f n a tu ral stream s is n o t p e rm itted in Masach u s etts, where program s are requi red t o fol l o w th e natu ral m eanders of th e stream . The th ree broad cat egori e s of wet l a nds alteratio n are o u trig h t lo ss, ch an g e s in th e ab io tic system an d ch an g e s in th e b i o tic co m mu n ity. Fillin g an d/ o r drai ni ng wet l a nds t o convert th em t o upl and i s a m o squi t o -control pract i ce th at has been al l but el i m i n at ed i n Massachusetts. There is no indication that MCPs are in t e nt i onal l y reduci ng wet l a nd acreage i n order t o control

m o squi t o es. However, th e fact th at th e wet l a nds bounda ry rem a i n s essent i a l l y unm oved by a m o squi t o -control al t e rat i on does not m ean th at prof ound al t e rat i ons have not occurred. C h anges i n th e abi o t i c sy st em and bi ot i c com muni t y are deepl y i n t e rt wi ned, though phy si cal control m o st

o f

ten cau ses ab io tic ch an g e s wh ich th en cause bi ot i c changes. For channel s changes i n fl ow rat e s, m i crohabi t a t s , sedi m e nt l o ad, sedi m e nt at i on, and groundwat er i n t e ract i ons can al l occur. For wet l a nds (out si de of channel s ) changes can include lost water-storage capaci t y , i n creased sedi m e nt at i on and pol l u t a nt l o ad, changes i n wat e r depth, and changes i n groundwat er hy drol ogy . W h en a stream i s al t e red t o i m prove wat e r fl ow for th e purpose of rem ovi ng st andi ng wat e r, ei th er wi th i n the stream or from adj acent wetlands, a num ber of change s m a y take place. By defin ition, im proving water flow increases runoff. This, in turn, m a y decrease the surface-water storage capacity of the wetland system and decrease th e cap ab ility o f th e wetlan d to retain lo ad (su s p e n d e d so lid s). Th is m a y in crease th e lo ad o f th e water m o v i n g th rough th e stream (B rown 1988). Increasi ng runoff i n t o a gi ven stream t e nds al so t o i n crease erosi on, whi c h further increases load (W illiam s & Feltm antle 1992). Not only is total flow increased, but alteration tends to i n crease peak fl ow, whi c h i s associ at ed wi th reduct i ons i n faunal di versi t y (Hy n es 1972). The effect s of i n creased fl ow and l o adi ng are m a ny . At i t s m o st obvi ous, hi gher peak fl ows i n crease scouri ng of th e stream bed by gravel and sand bei ng tr ansport e d by th e wat e r. B o t t o m dwel l i ng ani m al s are ei th er affect ed on-si t e or swept downstr eam , l eavi ng an i m poveri shed com muni t y as fl ows retu rn t o norm a l (Hy n es 1972). Increased fl ows can al so rem ove organi c m a t t e r, l eavi ng a sandy bot t o m on whi c h m acrofauna i s reduced (W ard 1992). As st at ed earl i e r, hi gher peak fl ows al so encourag e erosi on, a process th at can i n crease stream l o ad l ong after sedim e nt controls put in place duri ng the actual drainage work are rem oved. Hig h lev e ls o f su sp en d e d so lid s alter th e stream h ab itat b y : 1. reduci ng l i ght penetr at i on 2. reduci ng pri m ary product i on3. al t e ri ng th e tr ophi c structure 4. al t e ri ng nutri ent dy nam i cs 5. changi ng th erm a l condi t i ons 6. reduci ng oxy gen l e vel s (W ard 1992). These effects can, in turn can have th e following im pacts on the stream fauna: 1

. ab ratin g resp irato r y ep ith elia 2. cl oggi ng respi r at ory structures 3. reduci ng feedi ng rat e s 4. reduci ng feedi ng effi ci ency 5. i n creasi ng exposure t o t oxi ns 6. reduci ng vi si on 7. i nduci ng organi sm s t o dri f t
. Al l of th ese effect s can al t e r behavi or pat t e rns, change pr edat or/ p rey i n t e ract i ons and change th e out com e of i n t e r and intra-specific com p etition (W ard 1992). M a i n t e nance for th e purpose of reduci ng m o squi t o breedi ng al so i n cl udes rem ovi ng obstr uct i ons wi th i n stream s. Tree branches and fal l e n tr ees are a part i c ul arl y i m port a nt part of th e stream envi ronm ent , provi di ng food, living space, concealm e nt from predator s, protection from abiotic conditions and em ergence sites (W ard 1992). They al so provi de vari ed m i crohabi t a t s by deepeni ng and sl owi ng fl ow on th e upstr eam si de and oft e n creat i ng deeper pools on the downstream side. Rem oving these obs tructions dim i nishes the variability of the stream ecosystem
. At th e o th e r en d o f th e flo w -rate sp ectru m , in creasin g p eak flo w m a y lead to faster d r yin g in in term itten t stream s. Th e in sect fau n a(an d b i o tic co m mu n ity in g e n e ral) o f in term itten t stream s d o e s n o t o v e rlap to a g r eat extent with that of perm anent stream s (W ard 1992). As a ge neral rule, this is because interm ittent stream dwellers have evol ved t o deal wi th th e dry i ng down stream . Survi v al m echani s m s i n cl ude l eavi ng th e stream (swi m m i ng down stream or em ergi ng as l a nd-l i v i ng form s), survi v i ng i n cray fi sh burrows or rem a i n i ng pool s of wat e r, bury i ng either at shallow depths or quite d eeply into the substrate or hiding under rocks or leaflitter within or along the
stream course (W ard 1992). Stream s th e dry m o re qui ckl y , and st ay dri e r l onger, m a y di srupt al l of th ese t echni ques as i n sect s th at em erge as adul t s m a y not have enough t i m e t o com p l e t e devel opm ent (the pri m ary exam pl e bei ngm o squi t o es th em sel v es), rem a i n i ng pool s m a y decrease i n si ze and num ber and shal l o w burrows and hi di ng si t e s under rocks and leaf litter m a y becom e too dry to support the fauna hiding there. The effect of rapid drying brings up the aspect of the hyporheic zone. This is the interstitial space between
th e substr at e part i c l e s i n a stream bed. W i th i n th e hy porhei c zone th e m acrofauna can fi nd shel t e r from fl oods, drought and extrem e tem p eratures, can find suitable and pred ictable conditions for im m o tile stages such as eggs, pupae and di apausi ng ny m phs and l a rvae and, part i c ul arl y for earl y i n st ars, prot ect i on from predat i on. Gravel beds provi de th e best hy porhei c zones and ani m al s can oft e n be found m a ny feet down (W ard 1992). Thi s hy porhei c zone fauna can be an im portant s ource of recolonizing organism s after a stream bed is denuded (W illiam s & Feltm antle 1992). Excessive drying can reduce the viability of the hyporheic zone. Sedim e ntation, both within stream beds and in wetlands into which stream s flow, is a problem because it can alter the stream bed com position, thereby altering the fauna, and can clog interstitial spaces, thereby reducing
th e hy porhei c zone and/ or reduci ng groundwat er recharge. Sedi m e nt s can al so i n crease exposure t o pol l u t a nt s as th ey provi de addi t i onal si t e s for pol l u t a nt bi ndi ng whi l e su spended, and th en carry th e pol l u t a nt s t o th e benthi c fauna. M C Ps rout i n el y conduct m a i n t e nance t o rem ove sedi m e nt s. Therefore, t h ere i s good reason t o expect t h e overal l effect of m a i n t e nance m a y be t o reduce th e negat i v e i m pact s of sedi m e nt at i on wi th i n th e stream . In such cases, i t woul d be preferent i a l t o devel op sy st em s desi gne d t o prevent th e deposi t i on of road sand i n t o drai nage system s, rath er th an to p r ev en t th e rem o v a l o f th at sand, once i t has ent e red th e sy st em . R e m ovi ng th e dense,
rot t i ng m a sses of grass cl i ppi ngs th at are dum ped i n t o stream s by propert y owners shoul d al so i m prove overal l
stream q u a lity.

Up t o th i s poi nt th e di scussi on has focused on th e stream i t s el f, but freshwat e r wet l a nd al t e rat i ons are t y pi cal l y desi gned t o change st andi ng-wat e r wet l a nds t o soi l

- satu rat e d wet l a nds (New Jersey DEP 1997). The obvi ous probl em i s th at any organi sm th at requi res st andi ng wat e r for peri ods other th an peak fl oodi ng, th e wet l a nd

m a y becom e unusable. Mosquitoes fit th is definition perfectly, but so do m a ny other organi sm s. Many species of

am phi bi ans use t e m porary st andi ng wat e r for breedi ng and are becom i ng scarce as these h ab itats are elim in ated

. Increased drai nage al so m a y have an effect on groundwat er. Preci pi t a t i on and i n fl ow det e rm i n e th e

am ount of water initially available to a wetland for gr ound water recharge (Todd 1972). Increasing the am ount of wat e r rem oved from th e wet l a nd pri o r t o percol at i on dow nwards can decrease the cap acity o f th e wetlan d torecharge groundwat er suppl i e s. Not onl y can groundwat er recharge wi th i n th e wet l a nd l o wered, i t can be l o wered wi th th e out fl owi ng stream as wel l

. Duri ng peak fl ows, water m o v e s fro m th e stream in to th e su b s trate an d raises
th e wat e r t abl e (i ncreases groundwat er). As th e fl ow decl i n es, groundwat er percol at es back i n t o th e stream (i f i t does not , th e stream dri e s out ). B y el i m i n at i ng upstr eam reservoi rs (wet l a nds), m o re wat e r fl ows out of th e sy st em initially, leaving less water within the system . As water le vels fall, groundwater discharg e occurs sooner than m i ght otherwise be the case. If nothing else , stream depth is liable to vary m o re widely after adjacent wetlands are red u ced to so il satu ratio n . W h at i s m o st needed i s a com p rehensi v e underst a ndi ng of th e tr ue ecol ogi cal cost s of phy si cal al t e rat i ons for m o squito control. This is particularly im portant because, although the environm ental effects of pesticides receive the lion’s share of concern, it is possible that the long-term effects of physical controls m a y have a greater effect on th e envi ronm ent th an does pest i c i d e use (B uchsba um 1994). Thi s m a y be especi al l y tr ue t oday wi th th e swi t c h from broad-spectrum , m o re-persi st ent pest i c i d es t o m e thoprene and B t i

. New Jersey has recently updated it’s B e st M a nagem e nt Pract i ces for M o squi t o C ontrol and Freshwat er W e t l a nds M a nagem e nt and M a ssachuset t s shoul d l ook t o such gui del i n es t o est abl i s h a prot ocol for phy si cal control i n freshwat e r wet l a nds. At a m i ni mu m th e com m on-sense requi rem e nt s th at al l al t e rat i ons be pl anned (not random ), necessary , and desi rabl e shoul d be ri gorousl y appl i e d t o al l M C P wat e r m a nagem e nt project s regardl e ss of whether
th ey are defi ned as new or m a i n t e nance work. Th e North East M a ssachuset t s M C P St andards for Di t c h M a i n t e nance (Appendi x F) can be vi ewed as a st art i ng poi nt for a st at ewi d e prot ocol , though i t fai l s t o m e nt i on th e need for sedi m e nt control s duri ng m a i n t e nance work and l eaves th e M C P superi nt endent wi th wi de l a t i tude for det e rm i n i ng th e necessi t y of a gi ven project . A res ponse from th e M a ssachuset t s Audubon Soci et y (al s o Appendi x F) t o th ese St andards provi des addi t i onal com m e nt s whi c h de serve consi d erat i on when a prot ocol i s est abl i s hed.

c. Vernal Pool s. Vernal pool s form i n c ont ai ned depressi ons i n whi c h wat e r st ands for a peri od of several m onths, general l y from m i d- t o l a t e wi nt er th rough th e spri ng. W a t e r ei th er com e s i n th e form of

snow m e l t or spri ng preci pi t a t i on or can be a resul t of a ri si ng wat e r t abl e. Som e pool s dry down wi th i n t w o or th ree m onths, others m a y onl y dry when th e wat e r t abl e i s l o wer th an norm a l , resul t i ng i n a pool th at i s sem i

perm anent
. R e gardl e ss, a key feature of vernal pool s i s th at th ey undergo peri ods of dry down. Vernal pool s m a y have perm anent i n l e t s but do not have perm anent out l e t s (Kenney 1995).There are num erous obl i g at e speci es for vernal pool s, th e m o st vi si bl e of whi c h i n cl ude fai r y shri m p , th e wood frog ( Rana syl v at i c a ) and several speci es of sal a m a nder ( Ambyst oma spp.). The M a ssachuset t s Di vi si on of Fi sheri e s and W i l d l i f e (Publ i cat i on #15498-10-600-6-1-88C .R ) has creat ed guidelines for certifying vernal pool ha bitat on the grounds that m a ny vern al pool species cannot successfully survi v e wi thout vernal pool s and th at vernal pool s are under pressure from cont i nued devel opm ent wi th i n th e st at e. The cert i f i cat i on program i s coordi nat e d by th e Natu ra l Heri t a ge and Endangered Speci es Program (NHESP - see next sect i on). “Aut om at i c” prot ect i on i s gi ven t o vernal pool s onl y i f th ey 1. occur ei th er (a) wi th i n th e 100 y ear i n l a nd fl ood pl ai n or (b) on “i sol a t e d l a nd subject t o fl oodi ng” (as defi ned i n th e regul at i ons at 310 C M R10.57 (2)(b)); and 2. i t s exi s t e nce and l o cat i on has been cert i f i e d by th e M a ssachuset t s Di vi si on of Fi sheri e s an d W ild life. C u ri ousl y , upl and vernal pool s are not grant e d th e sam e prot ect i on but m a y be cert i f i e d as vernal pool s. The NHESP does not seek out pool s t o cert i f y ; i t cert i f i e s subm i ssi ons from th e publ i c . A gui debook for vernal pool certificatio n ( W i cked B i g Puddl es ) i s avai l abl e t o hel p those who wi sh t o subm i t a vernal pool si t e for cert i f i cat i on (Kenney 1995). Mo sq u ito es, p a rticu l arly Ae. canadensi s , al so use vernal pool s for breedi ng. From a control perspect i v e, vernal pools are im portant because, due to increasing protection, ve rnal pool habitat is ofte n left undeveloped while the land adjacent to the pool is built up. As a result, m a ny new devel opm ents surround known breeding sites. R e gardl e ss of th e wi sdom of devel opi ng so cl ose t o ve rnal pool s, m o squi t o -control personnel are charged wi th
control l i ng th e m o squi t o es com i ng from th e pool

. d. R a re and Endangered Speci es. Hy nes (1972) st at es th ree axi o m s of runni ng wat e r b i o tic co m mu n ities: 1. The great er th e di versi t y of the abiotic system , the greater th e num ber of species within the system
. 2

. Th e m o re co n d itio n s d e v i ate fro m th e n o r m a l, th e fewer sp ecies will b e p r esen t, b u t th o s e rem a in in g will b e p r esen t in g r eater n u m b e rs. 3. The l onger a sy st em i s l e ft undi sturbed, th e ri cher and m o re st abl e i s th e bi ot i c com muni t y . Operat i ng under th e assum p t i on th at i t

i s rare and endange red speci es whi c h are m o st l i k el y t o be l o st from th e sy st em fi rst , th e above st at em ent s woul d suggest th at re duct i ons i n habi t a t di versi t y , al t e rat i ons from th e natu ral state, an d freq u e n t d i stu rb a n ces will all wo rk ag ain s t th ese sp ecies. Ch an n e lizatio n o f stream s red u ces d i v e rsity b yrem ovi ng obstr uct i ons, strai ght eni ng th e channel and i n creasi ng fl ood l e vel s . W e t l a nds changed from st andi ngwat e r t o satu rat e d-soi l regi m e s have been drast i cal l y change d from th ei r natu ral st at e. M a i n t e nance i s ongoi ng, as i s the disturbance it causes. The key quest i on i s , however, t o what ext e nt does m o squi t o control contri but e t o th e above probl em s. Fi rst , M a ssachuset t s M C Ps do not channel i ze stream s, as th ei r cert i f i cat i on m a nual cal l s for fol l o wi ng th e exi s t i ng m eanders. Second, M C Ps work nei th er i n hi st ori cal l y undi sturbed, nor current l y undi sturbed stream s. There i s every reason t o argue th at th ere i s no speci fi c “natural ” st at e th at can be assi gned a di t c h dug by m a n and in term itten tly filled with ro ad san d an d g r ass clip p i n g s . Ev en with n a tu ral stream s, th e “n atu r al” h ab itat in wh ich
th ey fl ow has l ong been al t e red and cont i nues t o be al t e red. The Natu ral Heri t a ge and Endangered Speci es Program (NHESP) was creat ed i n order t o conserve and prot ect those pl ant s and ani m al s not hunt ed, fi shed, tr apped or com m e rci a l l y harvest e d i n th e st at e. The program ’s hi ghest pri o ri t y i s t o i nvent ory ra re and endangered speci es and t o deve l op conservat i on pl ans th rough research,

m a nagem e nt and habi t a t prot ect i on for those speci es. One such program th at di rect l y i m pact s m o squi t o control i s th e vernal pool cert i f i cat i on program m e nt i oned above. The NHESP al so revi ews proposed al t e rat i ons t o wet l a nds habi t a t s under th e W e t l a nds Prot ect i on Act (M .G.L. c. 131, s. 40 and regul at i ons 310 C M R10.00). NHESP has produced a seri es of est i m at ed habi t a t m a ps for rare and endangered speci es ( Massach u s etts Natu ral Heritag e Atlas ) whi c h proponent s of a gi ven al t e rat i on are required to check. Should a project fall within an estim ated habitat, NHESP w ill then determ ine if the area to be altered is actu a l wetlan d h ab itat fo r a state-listed sp ecies. Th e resu lts o f th e NHESP d e term in atio n are g i v e n to th e i nqui ri ng M C P. The M a ssachuset t s Endangered Speci es Act (M .G.L . c. 131A and regul at i ons 321 C M R10.00) prohi bi t s th e “t aki ng” of rare pl ant s or ani m al s. From a m o squi t o -control perspect i v e, th e m o st i m port a nt defi ni t i on of “tak in g ” is d i sru p tin g n e stin g , b r eed in g o rfeed in g sites o f an im als o rk illin g o rcu ttin g a p l an t. Asid e fro m d i rectly prot ect i ng rare or endangered speci es, th i s Act al so al l o ws areas t o be desi gnat e d “si gni fi cant habi t a t s .” Al t e rat i ons in “sig n i fican t h ab itats” req u i re a p e rm it fro m th e Div i sio n o f Fish eries & W ild life. In Massachusetts, the species that have caused m odifi cations in m o squito control practices are the Bluespot t e d sal a m a nder ( Ambyst oma l a t e ral e ), M y st i c Val l e y am phi pod ( C r angonyx aberrans ), and banded bogs k i mme r( Willia mso n i a lin tn eri ). In addi t i on, di t c h m a i n t e nance i n vernal pond areas has been curt ai l e d t o prot ect th is typ e o f h ab itat. Oth e r an im als fo r wh ich co n cern s have been rai s ed are th e y e l l o w-spot t e d tu rt l e and osprey

. The presence of a threaten ed species need not prevent water m a na gem e nt, however. In the East Volusia Mosquito Control District in Daytona Beach, Florida, OMW M was carried out in a salt m a rsh that contained the Atlan tic salt m a rsh sn ak e ( Nero d i a cla r kii ta en ia ta ). An observer wal k ed i n front of th e di t c hi ng m achi n ery and

wo rk was h a lted u n til o b s erv e d sn ak es left th e area. In p r actice th e sn ak es were d i fficu lt to sp o t an d sev e ral were seen in the freshly cut ditches behind the ditcher. Two dead snakes were found, and assum e d killed by the work. The dead snakes were handled as “inc idental take” and placed on ice for de livery to the Florida Gam e and Fresh W a t e r Fi sh C o m m i ssi on (Goode 1996). W i th an i n creased underst a ndi ng of th e ecosy st em s i n whi c h m o squi t o control takes place, m o squito control projects should im prove their ability to work in areas c ontaining endangered species with m i nim a l im pact to those species. Un d e r th e cu rren t system m o sq u ito -co n tro l m a in ten a n ce activ ities are ex em p t

fro m th e Massach u s etts W e tland Protection Act, leaving only th e federal 401 W a ter Quality Certifica tion Act and both the Massachusetts and federal Endangered Species Act as m e thods for regulating m a intenance. Unfortunately, water quality, while i m port a nt , does not address th e i ssue of changi ng habi t a t and th e presence or absence of a rare and endangered sp ecies h a s little to d o with th e m e rits o f a g i v e n p r o j ect. Rare an d en d a n g e red sp ecies will p r o b ab l y in crease in th eir im p act fo r sev e ral reaso n s . First, as d a ta is collected on these species, additional species and additi onal habitats will m o st likely com e under protection. Second, resi dent i a l areas are creepi ng cl oser t o wet l a nds areas. The net effect i s th at th e cl ash bet w een econom i c developm ent and environm ental protection will likely increas e, with m o squito control being one com ponent of an i n t e nse debat e . Agai n, a m o re com p rehensi v e underst a ndi ng of th e tr ue ecol ogi cal effect s of m o squi t o control i s req u i red to b e tter d e term in e th e co st/b en efit ratio fo r d i fferen t typ e s o f m o sq u ito co n tro l. D. Food W e b Effect s of M o squi t o C ontrol

. Throughout th ei r l i f e cy cl e m o squi t o es are a part of th e food web, both as consum er s and prey . As l a rvae

m o st speci es feed on al gae, prot ozoa, and organi c debri s (Pennak 1953). As adul t s th ey dri nk nect ar and th e fem a l e s of m o st speci es t a ke bl ood m eal s from a wi de vari et y of ani m al s. Larval m o squi t o es are eat en by an i m pressi ve array of ani m al s (B at es 1949) whi l e adul t m o squi t o es are t a ken by spi d ers, predat ory fl i e s, odonat e s,bats and birds (Collins and W a shino 1985). Given that m o squitoes are so thoroughly em bedded in the food web,
th e quest i on ari s es as t o th e effect of rem ovi ng a l a rge percent a ge of th e m o squi t o es from th at food web. At

fi rst gl ance, th e effect woul d appear t o be l a rge, part i c ul arl y i n habi t a t s wi th dense l a rval popul at i ons. Ho wev e r, m o sq u ito es are r-strateg ists, in th at th ey p r oduce l a rge num bers of eggs th at devel op qui ckl y (when i m m e rsed i n wat e r) t o adul thood. M o st pest speci es seek out t e m porary and spat i a l l y di sconnect ed habi t a t s for breedi ng and can com p l e t e a breedi ng cy cl e l ong before an adequat e predat or com p l e x can devel op. M o squi t o es are, th erefore, a hi ghl y unpredi c t abl e food source for predat ors, and predat i on rat e s mu st be equal l y unpredi c t abl e (this section will focus on predation, as parasites a nd pathogens are not widesp read control agents in Massach u s etts). Th is is b o r n e o u t b y th e fact th at m o sq u ito p r ed ato r s are g e n e ralists wh ich can read ily switch to other prey when m o squitoes becom e scarce (Collins and W a shino 1985). In a study in Florida, im m a ture

m o squi t o es m a de up over 50% of th e di et of several speci es of sal t m arsh fi sh ( Fundul us conf l u ent u s, Lucani a parva, Gambusi a a. hol brooki ). But each of these species fed on othe r item s as well, including copepods, shrim p , other fi sh and even som e pl ant m a t e ri al (Harri ngt on and Harri ngt on 1961). One i m port a nt poi nt regardi ng predat i on and l a rval broods i s th at th e concept s of handl i ng t i m e and satiation com e in to play (Varley et al. 1973). A predat or mu st spend a certain am ount of tim e with each prey. Hydrophilid larvae took several m i nutes to feed on larvae and pupae taken in a panne in Tiverton, Rhode Island (C hri s t i e , pers. observat i on). Not onl y does i t t a ke t i m e t o cat ch and eat th e prey , but i nvert ebrat e predat ors are typ i cally n o t mu ch larg er th an th e m o sq u ito larv ae th ey are attack in g . Satiatio n mu st p l ay a ro le in lim itin g p r ed ato r t a ke, part i c ul arl y when m o squi t o num bers are hi gh. Predat ors can pl ay an i m port a nt rol e i n regul at i ng m o squi t o num bers i n som e si tu at i ons. That m o squi t o es are absent from wat e rs wi th fi sh popul at i ons i s wel l known. Less wel l known i s th e i n fl uence of chaobori d l a rvae, whi c h can severel y reduce m o squi t o popul at i ons i n vernal pool s (M orri son and Andreadi s 1990). In th i s case th e l a rvae are present i n snow-m el t pool s for approxi m a t e l y t w o m onths, so predat i on has t i m e t o operat e as a regul at i ng m echani s m . Al though adul t m o squi t o es are eat en by num erous predat ors, i t i s rare th at th ey m a ke up an appreci abl e proport i on of th e di et of any one predat or. One except i on i s th e spi d er Tet r agnat ha mont ana fo r wh ich , in Po lan d ,
m o squitoes m a de up 74% in June and 62% in July of all prey captured (Collins and W a shino 1985). Bats and purpl e m a rt i n s are not effect i v e m o squi t o predat ors nor do m o squi t o es form a si gni fi cant part of th ei r di et
.Fro m a m o sq u ito -co n tro l p e rsp ectiv e, th e m o sq u ito es t o be control l e d are, for th e m o st part , those whi c h have escaped predat i on t o becom e predat ors i n th ei r own ri ght . In th e absence of sci e nt i f i c dat asupport i ng th e necessi t y of m o squi t o es i n th e di et s of speci fi c ani m al s, rem ovi ng m o squi t o es from th e food web by chem i cal , bi ol ogi cal or phy si cal control rem a i n s an easi l y just i f i abl e act i v i t y . Even so, control personnel shoul d t a ke care t o avoi d chem i cal appl i cat i ons where m o squi t o l a rvae are not present or are present i n very sm al l num bers, shoul d use
control m easures th at do not harm exi s t i ng predat or com p l e xes, and shoul d l i m i t control t o areas where control i s necessary, allowing natural cycles to c ontinue in areas where hum an activity a nd th e ri sk of di sease tr ansm i ssi on i s slight. One argum ent m a de in favor of Altosid is that it does not kill the young larvae, leaving them available as food for th e exi s t i ng predat or com p l e x. Up t o th i s poi nt , th e di scussi on has focused on th e effect of chem i cal control (i ncl udi ng Ba cillu s product s and IGR s ) of m o squi t o popul at i ons on other speci es. W i th i n th e cont ext of bi ol ogi cal control , one of th e pri m ary

reasons Gambusia are not being used in Massachusetts is the fear that they m i ght displ ace native species of fish, th u s alterin g th e n a tu ral b i o t a, n o t b y p r ed atio n b u t b y co m p etitio n fo r th e sam e reso u r ce. Phy s i cal control by wat e r m a nagem e nt m a y i n crease predation, as in OMW M , or m a y elim inate predator and prey as when wet l a nds are drai ned t o soi l satu rat i on. M o squi t o breedi ng mu st be thoroughl y docum ent e d before new work is done. Because disturban ces m a y displace som e species, and b ecause predator species tend to rebound

m o re slowly than their prey, m a intenance work should be conducte d only when necessary. E. No Program An o th e r altern ativ e strateg y to cu rren t m o sq u ito co n tro l p r actice is n o co n tro l. Man y co m mu n ities in Massachusetts have chosen this option. These town are usually outside of the enzoo tic EEE zone so the risk of h u m an d i seases tran sm itted b y m o sq u ito es is v i ewed as p r actically n il b y th ese co m mu n ities. In ad d itio n , th ey are not l o cat ed near sal t m a rshes and th ei r at t e ndant pest m o s qui t o probl em s. The m i d-sect i on of M a ssachuset t s , where

m o st no-control com munities occur, also has a m o re ru ral character, less wetland , lo wer hum an populations, and a lower m ean fam ily incom e than m o st eas t e rn areas wi th organi zed m o squi t o control program s. In general , th e vi ew

o f

th ese co m mu n ities is th at th e an ticip ated b e n e fits fro m m o sq u ito co n tro l d o n o t o u t weig h th e an ticip ated co sts and percei ved ri sks. A m o re preci se way of pol l i ng th e publ i c and confi r m i ng th i s opi ni on woul d be th rough est abl i s hi ng th e Hum a n Annoyance Threshold (HAT) for the town. Com mun ities in which the HAT is below the actual annoyancel e vel shoul d be persuaded t o choose th e no control opt i on si nce just i f i cat i on for control i s l acki ng unl ess a docum ented disease threat exists. In som e com munities, biting annoyance is created by a com b ination of biting insects (i.e. m o squitoes, bl ack fl i e s, bi t i ng m i dges and t abani ds) whi c h requi re com p l e t e l y di fferent control approaches. M a ny peopl e do not recognize the difference between these ins ects, especially in dim evening light. It is critical to accurately identify
th e bi t i ng i n sect s actual l y responsi b l e for th e hum an annoy an ce. In general , bl ack fl i e s and t abani ds onl y cause annoyance during the daytim e while m o squitoes and b iting m i dges are m o st annoyi ng from 6-10 PM. The HAT level for tabanids and biting m i dges is likely to be less th an for m o squitoes because of their m o re painful bites. Perhaps part of the reason why Berkshire County com munities have supported a MC program while other W e stern Massachusetts com munities have not, lies in the fact that this region suppor ts m a ny sum m e rtim e outdoor activities (e.g. cam ps, resorts, golf courses, Tanglewood, et c.). In addition, this m o re m ountainous region has a significant black fly annoyance problem s uperim posed on top of the m o squito problem . Vacationers are likely to have a l o wer HAT th an perm anent resi dent s si nce th ey are spendi ng m o re t i m e and m oney on out door recreat i onal activ ities. In addi t i on t o ri sk-benefi t consi d erat i ons, other cr i t e ri a for wei ghi ng th e control /no control opt i on are 1) the feasibility of successfully reduci ng annoyance below the HAT level, a nd 2) the adequacy of com munity resources for reducing annoy ance to acceptable levels. Towns wi th l a rge areas of m o squi t o -produci ng freshwat e r wet l a nd shoul d recogni ze th at effect i v e

m o sq u ito co n tro l in th ese h ab itats is d i fficu lt at b e st an d o f ten im p o ssib l e. As in d i cated earlier in th is rep o r t, perm anent wet l a nds do not usual l y produce l a rge num bers of pe st m o sq u ito es b u t in situ atio n s wh ere th ey d o , th e public needs to be aware that these wetlands are a valuable resource that mu st be prot ect ed from si gni fi cant perturbat i on and th at opt i ons for m o squi t o control are th erefore few. C o m muni t y pl anni ng boards and zoni ng l a ws can and should be used to restrict residential developm ent and other hum an activities from such wetland areas. Towns wi th annoy ance probl em s but wi th l a rge l a nd areas and th i n l y , scat t e red popul at i ons mu st understand that the sam e level of m o squito control achieved in m o re populated com munities will cost them significantly m o re per capita . In m a ny such cases, th e econom i c st atus of th e popul at i on m eans th at i n suffi ci ent t a x dol l a rs can be generat e d t o adequat e l y deal wi th th e probl em .Nantucket provi des an i n t e rest i ng case study . M o squi t o co n tro l h a d lap s ed in th e early eig h ties. Ho wev e r, by 1989 sal t m arsh m o squi t o es were becom i ng a si gni fi cant probl em i n th e west and north areas of th e i s l a nd. The
t o wn began appl y i ng Al t o si d (i ncl udi ng aeri a l appl i cat i ons of pel l e t s i n 1992) t o control th e m o squi t o es whi l e . g e ttin g th e req u i site p e rm its fo r OMW M in sev e ral west -end m a rshes (M adaket , W a rren’s Landi ng Eel Poi n t ) . The OM W M sy st em s were dug i n January 1993 (C hri s t i e 1993). It was hoped th at th e OM W M al one woul d be suffi ci ent t o control m o squi t o es but l a rge-scal e breedi ng cont i nued i n th e north end (Pocom o) and t h e l o w t i d al range has hi ndered th e effect i v eness of th e OM W M as dug. As a resul t , som e l a ri vi ci di ng cont i nues. The concl u si on on Nantucket i s th at m o squi t o control agai nst sa ltm arsh m o sq u ito es mu st b e co n tin u e d at so m e lev e l in order t o provi de resi dent s wi th th e sum m e r envi ronm ent th ey want . However, Nantucket does not t a rget freshwat e r

m o sq u ito es at all an d d o e s n o ad u lticid in g . Nan tu c k e t an d Cap e Co d to g e th er in d i cate th at ad u lticid in g is n o t a requi rem e nt even i n hi gh-t ouri s t areas. It

i s di ffi cul t t o m easure th e i m pact of choosi ng th e no control opt i on. The exam pl e of t o wns th at have l e ft , and l e ft and l a t e r rejoi n ed M C project s i s perhaps th e onl y avai l abl e basi s for est i m at i ng publ i c opi ni on concerni ng such i m pact . No docum ent a t i on of annoy ance l e vel s , cases of di sease, recreat i onal dol l a rs spent , et c., was ever attem p ted in th ese to wn s wh en th ey h a d m o sq u ito co n tro l v e rsu s wh en th ey d i d n o t . Th u s , p u b lic co m p lain ts were apparent l y th e m a i n i ndi cat i on of th e i m pact of th e no control opt i on th at was used i n gui di ng t o wn deci si on

m a ki ng. In th e 1986 quest i onnai r e, onl y about 10% of th e t o wns i n organi zed project s i ndi cat ed th at th ere had been
controversy rel a t i v e t o l eavi ng, joi n i ng, or rejoi n i ng a project . Those th at had experi enced controversy i ndi cat ed
th at 4 fact ors were about equal l y i nvol ved. These were: 1) m onet a ry constr ai nt s, 2) concern over th e effect i v eness of project control program s, 3) concern over th e safet y of th e m e thods used by th e project , and 4) concern over t h e environm ental im pact of the control procedures. Para doxically, 86% of these towns indicated they were unwilling to spend m o re m oney (if legally po ssible) to obtain m o re effective c ontrol and 67% indicated unwillingness to spend m o re m oney to support less hazardous control m e thods . However, the bias of the people filling out the questionnaire sent to each town m a y ha ve influenced these responses; no town in Massachusetts has actually polled th eir citizen s o n th ese q u e stio n s . In fact, so m e to wn s with i n project s have t a ken advant age of new provi si ons whi c h allo w to wn s to co llect ad d itio n a l m o n e y fo r MC activ ities wh ich p r o j ects can th en o n l y sp en d in th ese to wn s.Am ong t o wns th at actual l y wi thdrew from M C program s, m onet a ry constr ai nt s pl ay ed a rol e i n 73% of
th ese deci si ons, fol l o wed by envi ronm ent a l concerns i n 32% and concern over effectiveness in 27% of these cases. Towns th at cont em pl at ed wi thdrawi ng but di d not do so, i ndi cat ed th at m onet a ry and e ffectiveness considerations dom inated their concern. The num ber of t o wns i n M C Ps decl i n ed i n th e l a t e ei ght i e s. Econom i c fact ors, not envi ronm ent a l concerns, were th e dom i n ant reason gi ven for wi thdrawal

. Th is tren d h a s rev e rsed itself sig n i fican tly in th e last several years. The 1990 EEE problem is probably one reason, coupled with the fact th at several coastal program s tr i e d th e no-control opt i on and found m o squi t o num bers rose qui ckl y . M a ny t o wns i n th e B e rkshi r e C ount y and South Shore project s wi thdrew i n 1981 m a i n l y i n response t o Proposition 2-1/2 m onetary cons traints. The rem a ining 8 towns in Be rkshire County subsequently chose to continue as a mu lti-town Project (Note: the town of Lanesborough rejoined in 1986, the city of Pittsfield rejoined in 1988, and other t o wns are cont em pl at i ng reentr y ) . South Shore actual l y di sbanded as a project but by 1988 m o st t o wns had joi n ed nei ghbori ng M C project s i n Norfol k and Pl y m outh C ount i e s. These act i ons suggest th at th ese

co m mu n ities were n o t co n t en t with th e n o co n tro l o p tio n th at resu lted fro m th e d i sb an d i n g o f th eir fo rm er p r o j ect. Towns th at vol unt ari l y wi thdrew from M C project s but th en l a t e r rejoi n ed a project , di d so for a vari et y of reasons. These were i n order of th ei r i m port a nce: i n creased publ i c support for M C , i n creased m o squi t o annoy ance, alleviation of m onetary constraint s, threat of EEE, im proved m e thods and effectiveness of the project. The Environm ental Im pact Statem ent (Sjogren 1977) prepared for the Metr opolitan Mosquito Control District in Min n e so ta attem p ted to q u a n tify th e n o co n tro l o p tio n fo r th eir co m mu n ity. An y attem p t to d e v e lo p sim ilar estim ates for Massachusetts would be m eani ngl ess gi ven th e l ack of appropri a t e basel i n e dat a .VI. M O SQUITO CONTROL INTEGRATED PEST M ANAGEM E NT

A. Defin itio n o f IPM as it Relates to Mo sq u ito Co n tro l. 1. Overview of IPM. Few ideas stir m o re debat e i n pest control th an “Int egrat e d Pest M a nagem e nt ” (IPM ) . Every one agrees i t ’ s a good i d ea, but th ere agreem ent ends. For som e i t m eans, “No pesticides.” For others it m eans, “Extensive resear ch fol l o wed by careful i m pl em ent a t i on.” For others i t

m eans, “Don’t spray when they aren’t th ere and use several di fferent ch em icals when you do spray.” W h at

m a kes agreem ent so difficult is th at all th ree d e fin itio n s are, at least in part, correct. For th e purposes of th i s report , however, a si m p l e r st at em ent of IPM i s i n order. At i t s m o st basi c IPM is: A system designed to reduce the negative im pact of a pest species to an acceptable level while avoi di ng unnecessary addi t i onal probl em s (Vi r gi ni a C ooperat i v e Ext e nsi on Servi ce 1987). For m o squi t o control th e negat i v e i m pact s of m o squi t o es are reduct i on i n out door use, part i c ul arl y recreational, and disease transm ission. Probl em s th at have devel oped i n th e past are l o ss/ degradat i on of val u abl e habi t a t , exposure of non-t a rget organi sm s t o pest i c i d es, creat i on of new, som e t i m es worse, breedi ng h ab itat, an d resistan ce o f m o sq u ito es to p e sticid es in use. Of course, det e rm i n i ng whi c h of th ese probl em s i s unnecessary i s th e crux of mu ch debat e over m o squi t o control

. IPM was originated as a pest control strategy for ag ricultural system s. It ha s been m odi fi ed for urban sy st em s under th e nam e Urban Pest M a nagem e nt (UPM ). UPM vari es from IPM (m odi fi ed from Ol kowski et al

. 1978, Horn 1992, and C h ri st i e 1994) i n th at : 1. UPM sy st em s are general l y m o re com p l e x, particu l arly with reg a rd to d e term in in g th resh o l d s for control. 2. UPM takes place close to large num bers of people. 3. C ontrol deci si ons are oft e n m a de for aesth et i c , not econom i c reasons. 4. Pest s of hum an heal th requi re control even at sm al l num bers. Mo sq u ito co n tro l falls b e tween the classic agriculture-based IPM program and current UPM sy st em s. C ontrol of num erous speci es over a wi de range of habi t a t s i s m o re com p l e x th an m o st agri cul tu ral sy st em s (m odification 1) and control work ofte n takes place adjacent to (in the case of larviciding retention basins) or on (in the case of adulticiding) hum an populations (m odificati on 2). In addition, m o squitoes, even whencontrol l e d for nui sance purposes, woul d be cl assi fi ed as pest s of hum an heal th (m odi fi cat i on 4). However,

m o squi t o control deci si ons are not m a de for aesth et i c purposes (m odi fi cat i on 3) i n a m a nner si m i l a r t o t e nt caterp illars in a city p a rk

. The i m port a nt poi nt here i s not what t o cal l m o squi t o control IPM or UPM or som e th i ng ent i r el y di fferent (the t e rm i n t e grat ed m o squi t o m a nagem e nt has been proposed (Anony m ous 1995) but rath er t o m a ke i t

cl ear th at one cannot pi ck up bodi l y a sy st em desi gned for agri cul tu ral sy st em s and tr anspl a nt i t

i n t o m o squi t o control without accepting that m odificati ons have to be m a de. That being said, the second im portant point is
th at th e di ffi cul t y i n arri vi ng at a sci e nt i f i cal l y base d, econom i cal l y and envi ronm ent a l l y sound control program shoul d not be used as an excuse t o avoi d i m pl em ent i ng m o squi t o i n t e grat ed pest m a nagem e nt
. 2. Integrated Pest Managem e nt for Mosquitoes. Before an IPM program can be put in place, a strong organization mu st be in place. There is a huge difference between tossing som e pesticide at possible breedi ng si t e s and conduct i ng a ful l -fl edged IPM program . The organi zat i on mu st be adequat e l y funded, adequat e l y tr ai ned and provi ded wi th th e m a t e ri al s t o do th e job correct l y . At a m i ni mu m expert i s e i n m o squi t o bi ol ogy , wet l a nds ecol ogy , and program adm i ni strat i on are requi red. Adequat e st affi ng and resources are onl y th e fi rst st eps in creating an IPM program . The m a in step is in creating the analytical process wh ereby control deci si ons are m a de, eval uat e d and m odi fi ed. Thi s process

can b e d i v i d e d in to fo u rstep s: 1 ) Su rv eillan ce an d Mo n ito rin g , 2 ) Estab lish i n g Th resh o l d s fo r Actio n , 3 ) Prevent i on and C ontrol and 4) Eval uat i on.

a. Su rv eillan ce an d Mo n ito rin g (in c lu d i n g id en tificatio n ) . Th e in itial step in IPM is to survey th e exi s t i ng pest popul at i on and m oni t o r i t s occu rrence over t i m e. For m o squi t o es, adul t popul at i ons are

m oni t o red for th ei r di rect i m pact on peopl e whereas l a rval popul at i ons are m oni t o red for th ei r pot ent i a l i m pact after they em erge as adults. For adult populations, m on itoring is used to determ ine if adulticiding is required

an d to id en tify th e sp ecies o f m o sq u ito in a given area so that future larval control efforts can be directed at the appropri a t e breedi ng si t e s. Larval popul at i ons are m oni t o red t o det e rm i n e i f l a rvi c i d i ng i s requi red and/ or i f phy si cal or bi ol ogi cal control s are worki ng. Larval count s al so ai d i n det e rm i n i ng what areas are candi dat e s for water m a nagem e nt. Monitori ng should also take place post-control, in order to evaluate efficacy of various control m easures.Mo sq u ito es co llected d u r in g m o n ito rin g mu st b e id en tified , to th e ex ten t p o ssib l e, to sp ecies. Fo r adult m o squitoes, the species of adult will give a clue as to where larval m onitoring should be focused. For l a rvae, enough non-pest speci es exi s t th at fi el d st aff shoul d be abl e t o si ght i d ent i f y m o st of th e com m on speci es t o genera, pri m ari l y t o avoi d l a rvi c i d i ng a non-pest speci es. The habi t a t s i n whi c h breedi ng occurs or i n whi c h th e adul t m o squi t o es are m o st num erous mu st al so be identified. W e tlands should be m a pped. W ith the r ecent rise in the num ber of drainage basins in new d e v e lo p m en ts, an im p o r tan t asp ect o f m o sq u ito co n tro l is to m a in tain an u p - to -d ate list o f all su ch b a sin s an d work wi th l o cal bui l d i ng offi ci al s t o di scourage constr uct i ng m o squi t o -breedi ng basi ns. A third com ponent of m onitoring is to classify th e area in which control is to take place by hum an usage. Unless funding is not a constraint, the goal of surveillance and m onitoring should be to produce a site list p r io ritized b y th e lev e l o f m o sq u ito b r eed in g an d its p r o x i m ity to h u m an s. b. Est abl i s hi ng Threshol ds for Act i on. The goal of IPM i s t o keep pest l e vel s bel o w the Econom ic Injury Level (EIL). This is the level where the econom ic loss from pe st dam a ge exceeds the cost of control

. In m o squi t o control , th i s i s th e Hu m a n Annoy ance (or Di sease) Threshol d (HAT) and represent s th e hi ghest bi t i ng densi t y (or Di sease Inci dence) th at m o st citizen s in a co m mu n ity fin d to lerab l e. In to leran ce is usually exem plified by people m oving indoors, putting on repellent, leaving a cam pground etc.. HAT is general l y th e bi t i ng l e vel above whi c h m o st peopl e prefer t o pay t o have th e l e vel reduced th an put up wi th th e annoyance. This level will vary from com munity to co m munity and m a y be influenced by the species biting (Sjogren 1977), the tim e of day when annoyance occurs, and the duration of the period when HAT is exceeded. In agri cul tu ral IPM program s, a 2nd pest densi t y , th e Econom i c Threshol d (ET) i s est abl i s hed and

m oni t o red by frequent and sy st em at i c sam p l i ng of th e pest popul at i on. Thi s i s th e so-cal l e d act i on l e vel

. It i s the pest density that, if left uncheck ed, will result in the Econom ic Injury Level (EIL) being reached. It is a

com put er-assi st ed predi c t i v e l e vel , (l ower th an th e EI L) and i s based on previ ous experi ence, popul at i ons of beneficials, tim e of year, etc. It is d i fficu lt to tran slate th is m a n a g e m e n t co n cep t in to m o sq u ito co n tro l p r actice because the populations responsible fo r biting annoyance (adult fem a les) di ffer from those that need to be

m o n ito red an d co n tro lled (larv ae). Bitin g is n o t restricted to areas with th e larv al h ab itats an d it is d i fficu lt to
assess th e futu re bi t i ng i m pact of any gi ven l a rval popul at i on.Du rin g th e su rv eillan ce an d m o n ito rin g p h a se, wo rk ers n eed to estab lish th resh o l d s fo r th e v a rio u s control options they have. Thresholds m a y be esta blished based on those found in the literature but will g e n e rally req u i re lo cal m o d i ficatio n . Stan d a rd th resh o l d s fo r ad u lticid in g are g e n e rally g i v e n as co m p lain t calls for a gi ven area, l a ndi ng count s (m osqui t o es l a ndi ng on an observer per m i nut e) or l i ght tr ap count s (num ber of hum an-bi t i ng m o squi t o es col l ect ed per ni ght ). St andard th reshol ds for l a rvi c i d i ng and/ or wat e r m a nagem e nt are based on di p count s. Threshol ds need not be expressed i n t e rm s of exi s t i ng m o squi t o popul at i ons. In th e case of exi s t i ng p r o g r am s, th e th resh o l d fo r d r ain a g e m a in ten a n ce will m o st lik ely b e b a sed o n so m e v a riatio n fro m th e ex istin g cross-section of the system or som e m easure of water fl ow as com p ared t o a previ ousl y est abl i s hed norm

. Prevent i on cannot be based on exi s t i ng m o squi t o popul at i ons but mu st be based on th e pot ent i a l for popul at i ons t o devel op. Threshol ds for act i on are i n fl uenced by econom i c fact ors. Onl y program s wi th suffi ci ent operat i ng funds can ful l y expl oi t th e fl exi b l e control strat e gi es general l y found i n a ful l IPM program . Program s strapped for funds m a y have no, or very hi gh, thresholds for open m a rsh water m a nagem e nt, because the high initial
cost cannot be borne by th e program . Political realities also influence thresholds. Lo cal populations vary widely in their acceptance of

v a rio u s co n tro l m easu r es. In Massach u s etts th ere are p r o j ects th at ad u lticid e o n th e b a sis o f a sin g l e req u e st and there is one project (Cape Cod) that does not adulticide at all. Hum a n population dens ity and behavior patterns also influence thresholds for action. W h ere budgets are lim iting, funds will be earm a rked for areas in wh ich th e m o st p e o p l e will b e n e fit. Seash o r e co m mu n ities d e p e n d e n t o n su m m e r to u r ists will g e n e rally dem a nd higher levels of control, hen ce, lower thresholds for action, th an will thinly populated rural areas. Fi nal l y , envi ronm ent a l fact ors are al so i n cl uded i n est abl i s hi ng th reshol ds. C ontrol m easures th at have little im pact on non-target organism s can be conducted at lo wer thresholds than can control m easures that have large im pacts on non-targets. In add ition, thresholds for action will be in fluenced by the sensitivity of the l o cat i on i n whi c h control i s t o be conduct e d. An on- goi ng exam pl e i n M a ssachuset t s i s th e use of Al t o si d (m ethoprene) in endangered-species areas. In Suffolk County Bti use is perm itted, m e thoprene is not. Should B t i becom e si gni fi cant l y m o re cost l y th an m e thoprene, th e th reshol d (l arvae per di p) for l a rvi c i d i ng i n th e affected areas will m o st lik ely b e raised

.In sum m a t i on, th e choi ce of control m easures t o use, and th e ext e nt t o whi c h a gi ven control m easure i s used, i s det e rm i n ed by th e pest speci es and popul at i on, th e envi ronm ent i n whi c h th e pest popul at i on i s located, and hum an factors expressed in political and econom ic term s. De term ining which control options are available and how mu ch funding will be allocated to each, coupled with an understanding of the pest popul at i on, shoul d al l o w act i on th reshol ds t o be creat ed.

c. Prevent i on and C ontrol

. As a general rul e , prevent i on refers t o m a i n t a i n i ng a pest popul at i on bel o w an act i on th reshol d for control , whereas control refers t o bri ngi ng a pest popul at i on back down under the threshold for control. The line between the two, however, is blurred enough that there is little conceptu al reason t o separat e th em . C l eari ng a bl ocked di t c h so th at l a rvae are fl ushed out i s a short

- t e rm control m easure wi th l ong-t e rm prevent a t i v e effect s. Source reduct i on i s th e pri m ary prevent i on t echni que for m o squi t o control

. M a i n t a i n i ng wat e r fl ow th rough drai nage net w orks i s th e pri m ary freshwat e r m o squi t o control t echni que whi l e di t c hi ng (previ ousl y ) and open m a rsh wat e r m a nagem e nt (cu rren tly) are d e sig n e d to elim in ate th e iso l ated , sh allo w p a n n e s in wh ich sal t

- m a rsh m o squi t o es breed. Program s th at do not st

ress source reduct i on cannot m a ke l ong-t e rm reduct i ons i n m o squi t o popul at i ons. That bei ng sai d , th ere are cases where source reduct i on i s not possi bl e. The m o st obvi ous are areas where source reduct i on woul d i m pact an endangered speci es or where th e t y pe of source reduct i on necessary woul d severel y i m pact th e wet l a nd resource. In M a ss achuset t s any al t e rat i on i n such an area mu st undergo NHESP revi ew. Less obvi ous but equal l y real are cases where propert y owners deny perm i ssi on for source reduct i on project s or where th e breedi ng area i s si m p l y t oo l a rge for source reduct i on t o be econom i cal l y feasib le. Publ i c educat i on i s a second vi t a l com ponent of prevent i on. An educat ed publ i c shoul d be m o re willing to cooperate in elim inating m a n-m a de breed ing habitats, should better understand the trade-offs between the various available cont rol techniques, and should be m o re willing to fund m o re expensive approaches i f th e expense can be just i f i e d by a bet t e r l ong-t e rm benefi t
. A si de benefi t from publ i c educat i on i s that lines of com munication are usually strengthened, so that the econom ic and political aspects of m o squito control, areas often controlled by non- m o squito-control personnel, bear a str onger relationship to the realities of

m o squi t o control

.Co n tro l, in th e strict sen s e o f k illin g m o sq u ito es, is d o m in ated b y ch em ical u s e. Fo r ad u lt m o sq u ito es,

n o cu rren t co n tro l altern ativ e to p e sticid es ex ists. Ho wev e r, o p tio n s ex ist fo r larv al co n tro l. Bio l o g i cal co n tro l usi ng m o squi t o fi sh i s possi bl e. Expandi ng on th e concept of control t o underst a nd th at what i s bei ng control l e d i s th e negat i v e i m pact of m o squi t o es, rath er th an m o squi t o es th em sel v es, th en al l effort s desi gned t o reduce hum an exposure t o

m o squitoes constitute control. Public awareness b ecom e s a vital com ponent. This does not m ean teaching people to live with m o squito bites. It does m ean teaching people how to m a ke inform ed decisions about

m o squi t o control

. Thresholds are vital to the cont rol process because only through thre sholds can a rational response be

m a de to unusual circum stances. A quality IPM program cannot “fail” in the strict sense because it has control techniques available for each step in pest population increase (or, in the cas e of a disease threat, each increase i n th e ri sk of contract i ng th e di sease). Source reduct i on i s adequat e when m o squi t o breedi ng i s absent or l o w. Larv icid in g is trig g e red b y in creasin g larv al n u m b e rs. Lo calized ad u lticid in g is trig g e red wh en ad u lt populations pass a given thres hold. Finally, aerial adulticiding is av ailable when populati ons explode and/or the disease threat is high. d. Evaluation. Each control step is ev aluated for efficacy and fu ture actions m odified
to im p r o v e co n tro l o rred u ce n e g a tiv e im p acts. Field ev alu a tio n will g e n e rally u s e th e sam e m o n ito rin g techniques described above and the im portant criteria will be ch anges in the m o squito population and/or envi ronm ent
. Over t i m e, a st eady st at e shoul d devel op where real i s t i c th reshol ds tr i gger effect i v e responses. B. Aspects of IPM currently in place in Massachusetts m o squito control program s. 1. IPM Quest i onnai r e. Al ong wi th th e general quest i onnai r e sent t o th e pr oject s i n 1996, a separat e page concerni ng IPM was i n cl uded. In i t , project s were request ed t o provi de a de fi ni t i on of IPM and th en ei th er agree or disagree with a seri es of st at em ent s about IPM (Tabl e s 15 and 16).Tabl e 15. Project responses t o IPM Quest i onnai r e as gi ven. No Agree Disagree R e sponse 14. M o squi t o breedi ng out si de th e Program has an i m pact on adul t m o squi t o 7 1 popul at i ons wi th i n th e Program

. 1. The Program already practices IPM. 6 1 1 4. Quant i f y i ng hum an annoy ance i s di ffi cul t 6 2 2. The wi de range of breedi ng habi t a t s t o be m oni t o red m a kes i m pl em ent i ng 2 6 IPM difficult. 3. The wi de range of areas i n whi c h adul t m o squi t o es are a probl em m a kes 3 4 1 i m pl em ent i ng IPM di ffi cul t
. 5. C ontrol t echni ques and opt i ons are m o re oft e n det e rm i n ed by a vocal 5 3 m i n o r ity rath er th an the com munity average. 6. Li ght tr ap cat ches are i n fl uenced by t oo m a ny fact ors unrel at ed t o m o squi t o 2 6 population densities to be used as a reliable indicator of actual problem s. 7. C u rrent fundi ng provi des a rough m easure of a com muni t y ’s percei ved need 3 5 for m o squito control. 8. Personnel short a ges prevent col l ect i on of dat arequi red for IPM deci si ons. 4 4 9. Knowl e dge gaps prevent i m pl em ent a t i on of IPM

. 2 6 10. The wi de range of speci es of m o squi t o es t o be control l e d m a kes 3 5 i m pl em ent i ng IPM di ffi cul t
. 12. Predi c t i ng adul t m o squi t o popul at i ons from l a rval m oni t o ri ng i s not 4 4 sufficiently accurate. 1 3

. W a itin g u n til ad u lt m o sq u ito es are b itin g is to o late to in itiate co n tro l. 4 4 11. IPM i s not possi bl e i n m o squi t o control

. 0 8

The m o st encouragi ng aspect of th e answers i s th at none of th e ei ght project s respondi ng fel t th at IPM was not possi bl e i n m o squi t o control (St a t e m e nt 11) and si x of th e ei ght fel t th ey were al ready pract i c i ng som e form of IPM (S1). On a l e ss opt i m i s t i c not e, th ere was strong feel i ng th at quant i f y i ng hum an annoy ance i s di ffi cul t (S4). Of th e t w o (C ape C od and East M i ddl esex) th at di d not th i nk quant i f y i ng hum an annoy ance i s di ffi cul t , C a pe C od i s dom i n at ed by th e sum m e r t ouri s t season and i s probabl y i s not very hard t o fi gure out whether or
not m o squitoes should be controlled, the answer being, “Yes!” An a dditional concern when attem p ting to estab lish HATs is th at m o st o f th e p r o j ects felt th at v o cal m i n o r ities h a v e m o re say in m o sq u ito co n tro l th an d o e s th e co m mu n ity av erag e (S5 ) . Th ere is little q u e stio n th at th e HAT co n cep t, wh ile th eo retically o f v a lu e,

m a y be based on i n correct assum p t i ons about th e dri v i ng forces behi nd control deci si ons. Equal l y tr oubl i ng from a control perspect i v e i s th at m o st project s fel t th at m o squi t o breedi ng out si de th ei r Table 16. Project responses to IPM Questionnaire sort ed from highest num ber of “ag ree” responses to lowest. No Agree Disagree R e sponse14. M o squi t o breedi ng out si de th e Program has an i m pact on adul t m o squi t o 7 1 popul at i ons wi th i n th e Program

. 1. The Program already practices IPM. 6 1 1 4. Quant i f y i ng hum an annoy ance i s di ffi cul t 6 2 5. C ontrol t echni ques and opt i ons are m o re oft e n det e rm i n ed by a vocal 5 3 m i n o r ity rath er th an the com munity average. 8. Personnel short a ges prevent col l ect i on of dat arequi red for IPM deci si ons. 4 4 12. Predi c t i ng adul t m o squi t o popul at i ons from l a rval m oni t o ri ng i s not 4 4 sufficiently accurate. 1 3

. W a itin g u n til ad u lt m o sq u ito es are b itin g is to o late to in itiate co n tro l. 4 4 3. The wi de range of areas i n whi c h adul t m o squi t o es are a probl em m a kes 3 4 1 i m pl em ent i ng IPM di ffi cul t
. 7. C u rrent fundi ng provi des a rough m easure of a com muni t y ’s percei ved need 3 5 for m o squito control. 10. The wi de range of speci es of m o squi t o es t o be control l e d m a kes 3 5 i m pl em ent i ng IPM di ffi cul t
. 2. The wi de range of breedi ng habi t a t s t o be m oni t o red m a kes i m pl em ent i ng 2 6 IPM difficult. 6. Li ght tr ap cat ches are i n fl uenced by t oo m a ny fact ors unrel at ed t o m o squi t o 2 6 population densities to be used as a reliable indicator of actual problem s. 9. Knowl e dge gaps prevent i m pl em ent a t i on of IPM

. 2 6 11. IPM i s not possi bl e i n m o squi t o control

. 0 8

di stri ct has an i m pact on adul t m o squi t o popul at i ons wi th i n th ei r di stri ct (S14). The onl y project th at di d not was C a pe C od, whi c h i s m o re i s ol at ed th an are th e other project s. IPM program s th at stress wat e r m a nagem e nt of l a rval popul at i ons mu st be fl exi b l e enough t o al l o w project s t o control adul t s m o squi t o es com i ng i n from other areas. Looki ng at som e speci fi cs by project , Norfol k and Essex both agree wi th th e th ree st at em ent s (S2, S3, and S10) rel a t i ng t o th e wi de range of m o squi t o habi t a t s . Though th ese program s have both sal t

- m a rsh and freshwat e r com ponent s, th ei r di stri but i on of effort i s not m a rkedl y di fferent from Pl y m outh or Suffol k Co u n ties, wh ich d i sag r eed with all th ree statem en ts. No rfol k and Essex al so were th e two projects that agreed wi th th e st at em ent th at , “Knowl e dge gaps prevent i m pl em ent a t i on of IPM ” (S9). As both Norfol k and Essex M C Ps are act i v e i n pushi ng for stronger, m o re ecol ogi cal l y sound m o squi t o control , th ei r responses m a y be l e ss an i ndi cat i on of th ei r di ssat i s fact i on wi th IPM and m o squ i t o control and m o re an i ndi cat i on of th ei r desi re t o

see m o squi t o control IPM i m proved. 2. M o squi t o C ontrol IPM as pract i ced i n M a ssachuset t s t oday

.The strat e gy of IPM as devel oped for agri cul tu ral ecosystem s is an ecologica lly-based concept (Axtell 1979). It has y e t t o be ful l y appl i e d t o m o squi t o m a nagem e nt program s. IPM i s a strategy for m a nagi ng i n sect popul at i ons not a m e thod fo r co n tro llin g th em . It is m o re th an in teg r ated co n tro l wh ich is sim p ly th e

com b i n i ng of several control m e thods. M o squi t o contro l has a l ong hi st ory of i n t e grat i ng di fferent control

m e thods. The general feeling am ong m o st MC practitioners is that any significant larval population within flight range of residential areas will probably result in som e hum an annoyance and therefor e should be controlled. Few MC program s in the U.S.A. have developed annoyance thres hold levels for their com munities. No Project in Massachusetts has undertaken such an effort. In the Metropolitan MC District in Minneapolis/St. Paul, it was found th at th e HAT was 2 bi t e s/ 5 m i nut es bet w een 7-9 PM on t y pi cal sum m e r eveni ng. Thus, th e

m i ni mu m goal of th i s Di stri ct i s t o keep th e hum an bi t i ng rat e at or bel o w 1 bi t e / 5 m i nut es. Thi s num ber i s so low, however, that few projects are lik ely reach it consistently throughout their district. Therefore, whether or
not a gi ven breedi ng si t e i s l a rvi c i d ed i s m o re a funct i on of econom i c s th an of absol u t e m o squi t o num bers. Al though m a ny M C program s regul arl y m oni t o r adul t popul at i on l e vel s (wi th l i ght tr aps and l a ndi ng counts) they do it to evaluate larval control effectiveness and the need for adulticiding; not to determ ine when i m m e di at e l a rval control i s needed as i n th e case of agri cul tu ral IPM program s. However, l i ght tr ap count s, landing rates and com p laint calls are used to create a ge neral pi cture of th e need for m o squi t o control and project s wi th l ong-t e rm experi ence devel op l a rvi c i d i ng pl ans based on th i s hi st ori cal dat a . It

woul d be benefi ci al i f t echni ques for predi c t i ng futu re adul t bi t i ng annoy ance from l a rval count s could be developed. One way this could be accom p lished by m a rking different larval populations (for exam ple with Geim sa stain) and then assessi ng the subsequent contri bution of m a rked fem a les to the population biting hum ans i n nei ghbori ng areas (Fi s h & Josl y n 1984, Josl y n et al . 1985). A si m p l e r t echni que i s t o m a rk adul t s with a fluorescent dust, release them at the breeding site, and attem p t to recover them in adj acent biting areas (M orri s, et al . 1991). Thi s can show whi c h areas are be i ng affect ed by whi c h breedi ng areas. The drawback t o these types of is the need to do it for each species in question and, due to the large num ber of site-specific vari abl e s, for m a ny breedi ng si t e s. R e gardl e ss, studi es l i k e th i s woul d requi re a research el em ent not present i n the current Massachusetts system

.Assessm ent of the cos t/benefits resulting from outdoor recreati onal activities have been dealt with extensively in the literature (Pierce & Napier 1977, Bear dsley 1971, Moeller et al. 1976). The theoretical basis for m o st of th ese anal y s es i s found i n general wel f are th eory (Pi e rce 1971, Prest & Turvey 1965, W a l s h & W illiam s 1969). W h en applied to the assessm ent of econom ic benefits, these analyses represent attem p ts to establish the consum er surplus" (Blaug 1968). This surplus represents the consum ers willingness to pay" (W IP) for a specific service or facility e.g., a m o squ ito-free cam pground or park. Once determ ined, the W I P is used as a proxy for benefi t s em anat i ng from th e servi ce (M i s han 1976). John et al . (1987) est abl i s hed th e W I P for a Texas com muni t y t o be $22.44 per househol d ($18.96 pe r rent er househol d). Once th e benefi t s and cost s of m o squi t o control are assessed, i t i s possi bl e t o est abl i s h Econom i c Threshol ds (e.g., th e m o squi t o densi t y at wh ich th e co st o f co n tro l is eq u a l to th e v a lu e (estim at ed benefi t s ) forthcom i ng from th e control s (Edens & C ooper 1974, Edens 1977). A m a jor concern in all of these cost/benefit analyses is that they com p are dollar costs of various control techniques or discu ss consum er willingness to pay but they do not address ecological costs associated with m o sq u ito co n tro l. Du e to th e lo wer an d m o re sp ecific to x i cities o f n e wer p e sticid es, water m a n a g e m e n t

m a y not al way s be l e ss ecol ogi cal l y dam a gi ng th an pest i c i d e appl i cat i on. There i s no study t o dat e of th e cost s and benefi t s of M a ssachuset t s m o squi t o control program s. There i s good reason t o bel i e ve, even i f such studi es were done, th at th e resul t s woul d refl ect l o cal , current thought , as opposed t o som e underl y i ng “true” cost / b enefi t for m o squi t o control

. Vari abl e s th at woul d affect percei ved cost/benefit include relative econom ic st rength of the local com munity and of the state, recent weather patterns and th ei r i n fl uence on m o squi t o breedi ng, th e rat e and di rect i on of devel opm ent wi th i n th e com muni t y , and th e techniques available for m o squito cont rol. Regardless of the underlying vari ability of any cos t/benefit analysis, worki ng t o wards an underst a ndi ng of th e cost s and benefi t s of m o squi t o control i s desi rabl e. The fol l o wi ng i n form at i on woul d ai d i n such work: 1) Est abl i s h hum an annoy ance th reshol ds (HAT) 2) Docum e nt how hum an act i v i t y pat t e rns rel a t e t o HAT and econom i c fact ors 3) Determ ine cost/benefit analys is of control (willingness to pay) 4) Correlate HAT with a standard non-biting sam p ling m e thod (e.g. light trap) 5) Correlate densities of im m a tures with future levels of biting annoyance6) Est abl i s h th e ecol ogi cal cost s of vari ous control t echni ques. The cost / b enefi t of vari ous control opt i ons (e.g., perm anent vs. t e m porary control ) al so has been evaluated in recent papers (Ofiara & Allison 1986a, 1986b) but this should not be confused with the
cost / b enefi t of control program s. 3. Im provi ng Phy s i cal C ontrol

. Reducing pesticide use is not a prim ary goa l of IPM (Robinson 1996). Reducing unnecessary pest i c i d e appl i cat i ons and i m provi ng th e effect i v eness of pest i c i d e appl i cat i ons are goal s , and i m provi ng our knowl e dge of how a sy st em works oft e n resul t s i n pest i c i d e-use reduct i on, but th ere i s nothi ng i n th e concept of IPM th at m a ndat e s reduci ng pest i c i d e use. Indeed, at E ssex C ount y , when th ey est abl i s hed a l a ndi ng count rat e of 1 per five m i nutes for adulticidi ng, they found that the total area th at qualified for adulticiding jum p ed dram at i cal l y (W al t e r M ont gom ery , personal com muni cat i on) . Th at b e in g said , p e sticid e u s e rem a in s an issu e and i m provi ng non-chem i cal control s i s a desi rabl e goal

.

M o st organi zed M C project s i n M a ssachuset t s e ngage i n source reducti on acti v i t y . C u rrentsourcered u c tio n effo rts g e n e rally co n s ist o f clean in g an d rep airin g d itch e s an d o t h e r water co n t ro l stru ctu r es b u ilt previ ousl y rat h er t h an wi t ht

h e const r ucti on of new st ru ct ures. New const r ucti on i s l i m i t e d by St at e and Federal wetl and prot ecti on l a ws and regul ati ons. Al so, t h e ec onom i c s of source reducti on program s i s an i m port ant

co n s id eratio n . Th e h i g h e r in itial co st o f th is sem i -p erm an e n t co n t ro l strateg y m u st b e am o rtized o v e r th e m u ltip le y ears of anti c i p at ed benefi t
. It cannot be i m pl ement e d at al l when l i m i t e d annual budget s prevent M C Ps from acqui ri ng t h e l a rge up-front capi t o l sum s t h at are needed for m a jor source reducti on project s. Anot her short c om i ng

o f

th e cu rren t reg u l atio n s , as th ey ap p l y to m o sq u ito co n t ro l, is th ey fail to ad eq u ately d i fferen tiate b e tween n atu ral and m anm ade wetl ands. One m a jor advance al ready underway i s vastl y i m proved m a ppi ng t h rough Geographi c Inform ati on System s (GIS). GIS wetlan d s m a p p i n g can b o t haidm o sq u ito co n t ro l ag en cies in d e term in in g co n t ro l p rio rities but can be used by m o squi t o cont rol agenci es t o i n t e grat e t h ei r work wi t hot her l and-use agenci es (Gut he 1993). Very det ai l e d m a ps can al so be m a de when pl anni ng wat e r m anageme nt project s (Get tm an 1995).

a. Sal t m arsh m a nagem e nt Th ere are two m a j o r strateg i es fo r m an a g i n g tid al waters to ach iev e co n t ro l o f saltm arshm o sq u ito es: (1 ) l ong-t e rm fl oodi ng or i m poundment of t h e hi gh m a rsh t o prevent m o squi t o egg l ay i ng and encourage l a rvi vorousfi sh, or (2) drai nage of t h e hi gh m a rsh t o prevent wat e r from st andi ng for t h e 6+ day s requi red for t h e com p l e ti on of m o squi t o l a rval devel opment
. Some com b i n ati on or m odi fi cati on of t h ese tw o m i ght be consi d ered as a t h i r d
st

rat e gy . Perm anent or seasonal i m poundi ng of t h e enti r e hi gh m a rsh i s not a vi abl e opti on i n New Engl and' s grassy sal t m a rshes wi t hwi de ti d al fl uct u ati on (Provost 1969). Early source reduction work in grassy salt m a rshes consisted of grid ditches, initially dug by hand. .Everyone concerned now seem s to agree that such a blanket approach t o sal tm arsh di t c hi ng i s overl y dest ructi v e and l e ss effecti v e t h an m o re cust om i zed desi gns t hough t h e act ual i m pact s have been debat e d (B ourn & C o t t am 1950, Lesser et al . 1976, Provost 1977, Dai b er 1986, B u chsbaum 1994). Thi s approach i s no l onger practi ced or

reco m me n d e d , b u t m an y o f th ese o l d , sq u a re-b o tto me d d itch e s still criss-cro ss Massach u s etts salt m a rsh e s. Man y h a v e b eco me silted

- in sh allo w d e p r essio n s in wh ichm o sq u ito es b r eed . To av o i dth is, so me MC p r o j ects co n tin u e to clean an d m ain tain at least so me o f th e o l d g rid d itch e s. C ont our di t c hi ng grew out of t h e real i zati on t h at gri ddi t c hes oft e n fai l t o fl ush wi t ht

h e ti d es and therefore, unless continuously m aintained , they eventually silt in and form breeding. Contour ditches are m o re strategically placed and follow the natu ral topography of the m a rsh. Cont our ditching scheme s are essentially i n t e grat ed ext e nsi ons of nat u ral ti d al creeks and t h ey bet t e r t a ke i n t o account t

h e hy drody nam i cs of ti d al m a rshes. Although they are a m o re intelligent appr oach to ditch design, they are still ineffective in pr eventing m o squito breedi ng i n m any shal l o w pans and i s ol at ed, i rregul ar depressi ons whi c h charact eri ze t h e upper part of m any Massach u s etts salt m a rsh e s. An obvi ous al t e rnati v e t o m ai n t ai n i ng gri dor cont our di t c hi ng woul d be t o upgrade t h e gri d -di t c h sy st em s t o OM W M sy st em s. In a Rhode Isl and sal t m a rsh such a conversi on consi s t e d of creati ng a reservoi r wi t h i n an exi s ti ng di t c h, cl eani ng out t

hose secti ons of di t c h t h at functi oned as connect ors from t

h e reservoi r t o breedi ng p an n e s, an d u s in g th e sp o il to fill in d itch i n g th at was n o t serv in g a m o sq u ito -co n t ro l fu n c tio n . As a resu lt, breeding densities of hundreds per dip we re reduced to virtually none and la rviciding practically elim inated (C hri s ti e , personal com m

uni cati on). Thi s t y pe of work i s occurri ng i n M a ssachuset t s but coul d probabl y be increased. b. Fresh wat e r m a nagem e nt Natu ral W e tlan d s . Over the past decade there has grown up a tremendous force for the preservation of all wetlan d s , th e “n o - n e t-lo ss” p o licy. Th is p o licy is b a sed o n th ree assu m p tio n s :1) each and every wetland is of infinite value 2) t h at al l wetl ands are of equal val u e 3 ) th at an y actio n s o r o t h e r p r o p e rties sacrificed to m ain tain a wetlan d m u st h a v e less v a lu e th an th e wetl and i t s el f. (Gat es 1995). Th e ch allen g e fo r m o sq u ito co n t ro l p r o g r am s is to en su re th at a m o re b a lan cedset o f assu m p tio n s co me s to th e fore as our underst andi ng of wetl ands, m o squi t o es, and vect or cont rol i n creases. No IPM program for m o squi t o control can be adequately developed if the areas in which control takes place are off lim its to m anipulation. Just as

m o squi t o -cont rol personnel m u st become m o re aware of t h e ecol ogi cal cost s of m o squi t o cont rol , so t oo m u st advocat es of wetl ands preservati on become m o re aware of t h e benefi t s of m o squi t o cont rol

. Mo st p e rm an en t wetlan d s o ffer few o p tio n s fo r water m an a g e me n t . Drain i n g o r fillin g n atu ral wetlan d s are no longer considered acceptable practices. Extensive ex isting drainage networks are currently m aintained by the Mosquito Control Projects but new ditching is rarely perm itted. Most ex isting system s were not originally dug with m o squito control in m i nd. Unfo rtunately, a ditch system , once in place, alm o st invariably breeds m o squitoes i f

i t

i s not m ai n t ai n ed. A pri m ary goal for m o squi t o -cont rol program s and st at e agenci es shoul d devel op cri t e ri a for conti nued drai nage m ai n t e nance, usi ng t h e New Jers ey gui del i n es (New Jersey DEP 1997) and t h e Nort h East Massachusetts Mosquito Control and W e tlands Manageme nt District “Standards for Ditch Maintenance” as
st arti ng poi nt s. The prospect for source reducti on acti v i t y i n t h e t housands of acres of wooded swam ps com m on t h roughout t

h e east e rn t h i r d of M a ssachuset t s i s sl i m . The pri m ary vect or m o squi t o , C s . melanura , produced i n these swam ps is essentially an after dark, passerine bird feeder, and is unlikely to transm it EEE to hum ans and horses (Nasci & Edm an 1981a, M o rri s et al . 1980). Therefore, any effort t o cont rol t h i s m o squi t o i s perhaps

m

i splaced, though some success has been had with aerial applications of Altosid pellets (Henley 1992). If the vector(s) of EEE virus to m am m a ls were known, control effo rts directed against this m o squito would be a m o re logical and efficient way to interrupt disease transm ission during threatened ep id em ics. Th e m o st lik ely can d i d ates for such attention are Cq. perturbans, Ae. vexans, and Ae. canadensi s . Vernal pool s are bot h a val u abl e resource and a rel i a bl e source of m o squi t o es. Thei r si ze m a kes t h em

m o re amen ab le to h a b itat m o d i ficatio n b u t th eir v a lu e as nurseri es for am phi bi ans and ot her sem i -aquati c ani m al s

m a kes their preservation im portant. In rare cases, how ever, ditching (when possible) or filling sm all woodlandpool s i n cl ose proxi m i t

y t o hum an popul ati ons m ay provi de suffi ci ent benefi t s t o outwei gh t h e l o ss of some of these tem porary aquatic habitats. Vernal-pool certifi cation by NHESP will, over time, bring under protection of
t h e Di vi si on of Fi sheri e s and W i l d l i f e t

hose vernal pool s whi c h shoul d be l e ft undi st urbed. M o st vernal pool s slo w ly fill in n atu rally wh ile n e w o n e s are co n s tan tly b e in g createdin th e ro o t cav ities createdb y b l o w n o v e r trees. M a ssachuset t s forest s are currentl y m at u ri ng so ' b l o wdowns' and new vernal pool s m ay be i n creasi ng. Popul ati ons of t r ee-hol e Ae. triseria tu s seldom reach serious densities in Massachusetts at present but this could change. Because this species is a daytime biter, adap ts readily to discarded tires, and is a potential vector of La Crosse encephalitis, it bears careful monitoring. The city of La Crosse inW i sconsin has m ounted an effective

cam p aig n to n early elim in ate h u m an cases o f LAC en cep h a litis b y sim p ly rem o v i n g o l dtires an do t h e r sm all water-holding contai ners and filling in tree holes near residential areas (Parry 1983). This m odel for source reducti on of t r ee-hol e m o squi t o es i s undoubt edl y t h e m o st effecti v e way t o presentl y deal wi t h Ae. triseria tu s in areas where it become s a lo calized problem species. R e servoi rs and dug ponds . The m a jori t y of sm al l perm anent ponds and l a kes i n M a ssachuset t s are m an-m a de. They were creat ed by dredgi ng nat u ral seepage areas or by dam m

i ng stream s. M any M a ssachuset t s reservoi rs are old, having been built to provide pow er and water for adj acent factories built between the m i ddle of the 19th century and the depression years of this century. Some have become badly silted and eutrophic. Nearly all of
t h ese bodi es of wat e r creat e some m o squi t o habi t at , at l east al ong veget at e d shorel i n es and i n shal l o w upper reaches distal to the dam

. Anophel e s and Cu lex are the principal m o squitoes asso ciated with these wetlands and, when cattail or water willow invade along the shoreline, C q . pert urbans b eco me estab lish e d as well. Also , sm all perm anent ponds or reservoirs within wooded habitats often hatch large broods of univoltine Aedes along l eaf-packed borders duri ng spri ng fl oodi ng. Ol der dam s sel dom have fl exi b l e wat e r l e vel cont ro l st ruct ures. Thus, wel l

- est a bl i s hed pri n ci pl es for

m anagi ng m o squi t o es i n i m pounded wat e rs (Edm an 1964) can not be appl i e d i n m o st M a ssachuset t s reservoi rs. All new and rebuilt structures should include adequate control capabilities so that water level m anageme nt can become a m o squi t o cont rol opti on i n al l i m poundment s i n t h e fut u re. The m ai n feat ures of wat e r l e vel cont rol pl ans are: (1) m a xi m u m pool l e vel s when fl ood-wat e r Aedes are l ay i ng eggs, (2) gradual sum me r drawdown wi t h weekl y surcharges t o st rand fl oati ng debri s and keep wat e r out of t h e shorel i n e veget ati on t h at prot ect s Culex and Anophel e s l a rvae from wave acti on and predat ors, and (3) duri ng t h e spri ng egg hat c h peri od, keep pool l e vel sfrom rising above the levels m aintained during the previous year' s univoltine Aedes egg-l ay i ng peri od. Grass and scrub m a rshes creat ed by drai nage di srupti o n . M o st seri ous pest / v ect or pr oblem s associated with these h a

b itats are created in situ atio n s wh ere v e g e tatio n fav o r ab le to th e cattail m o sq u ito , C q . pert urbans has i nvaded t h e

m a rsh. Thi s m o squi t o i s di ffi cul t t o cont rol by conven ti onal l a rvi c i d es, i s an aggressi ve bi t e r of hum ans and domestic anim als, and m ay play a role in EEE epidem ics. Spring Aedes , and sum me r Anophel e s and Cx.

sa lin a r iu s p r o b l em s m ay b e asso ciatedwithth ese m a rshh a b itats as well. Also , a u n i v o ltin e b i rdfeed er, Cs. moristans , which m ay play a role in enzootic cy cles of EEE virus (Morris and Z i mme r m a n 1981), breed p r in cip a lly in th is categ o r y o f wetlan d

. There are tw o pot enti a l habi t at m anageme nt st

rat e gi es fo r elim in atin g b r eed i ng associated with these wetl ands and nei t h er i s popul arl y practi ced. One i nvol ve s rem ovi ng t h e veget ati on whi c h support s breedi ng (e.g., cattails). This can be done with a dragline provided the vegetation is still restricted to the pond border. Altern ativ ely, selectiv e h e rb icid in g o r h an drem o v a l wh en in v a siv e p l an ts lik e cattails first b eco me estab lish e d al ong t h e shore m ay be effecti v e i n some si t u ati ons. A second m anageme nt st

rat e gy i s t o correct t

h e drai nage disruption which created the wetland situa tion in the first place. This m ay be as sim p le as installing or lowering a cul v ert
. In cont rast , i t m ay be so com p l e x and expensi v e t h at i t

i s not a vi abl e opti on. W h en feasi b l e , rest ori ng natural drainage will perm anently elim in ate the wetland. This m ay be consider ed unacceptable despite the fact that
t h ese wetl ands are m an-m a de and of l i m i t e d l i f e expect ancy . The bui l d ers of roads, rai l r oads, and power or pi pe l i n es are responsi b l e for t h e m a jori t y of t h ese wetl ands. Expecti ng cont ract ors t o ret r oacti v el y address, at great expense, t h e publ i c heal t hand nui sance probl em s t h at t

h ey have creat ed i s perhaps unreal i s ti c . However, al l new const r ucti on whi c h i nvol ves si gni fi cant changes i n t opogra phy and nat u ral drai nage shoul d be revi ewed by an agency such as t h e SRM C B t o assess i m pact on wat e r fl ow and creati on of new wetl ands whi c h m ay produce pest / v ect or m o squi t o es. R o adsi de di t c hes and ti r e rut s . A m a jor source of refl ood Aedes are ditches that fail to co m p letely drain because of a l ack of cul v ert s or cul v ert s t h at are l o cat ed above t h e l e vel of t h e di t c h bot t o m . Heavy equi pment and t r act or ti r es l eave perm anent rut s i n soft t

u rf whi c h i s anot her m a jor source of refl ood breedi ng si t e s associ at ed wi t hdi t c hes and l o w-l y i ng fi el ds. B o t hof t h ese cat egori e s of m a n-m a de wetl ands can be prevent e d by proper engi neeri ng, construction, and m aintenance practices. W h ere these br eeding sites already exist, they can be perm anently el i m i n at ed by appropri at e l o weri ng of cul v ert s and re gradi ng work. Tapered cement aprons at bot h ends ofcul v ert s and cement l i n i ngs i n t h e bot t o m of roadsi de di t c hes i n resi denti a l areas wi t hpoor drai nage charact eri s ti c s can al so assi st i n preventi ng t h e creati on of t h ese breedi ng si t e s. M uni ci pal and st at e road crews shoul d be
cauti oned agai nst m o wi ng when t h e sod i s t oo soft t o ful l y support m o wi ng equi pment wi t hout creati ng depressi on in th e d itchb o tto m . St orm cat ch det e nti on and ret e nti on basi ns, orname nt al pool s, ti r es, and ot her m an-m a de cont ai ners . Good sani t a ry practi ces prom ot ed t h rough homeowner educati on can el i m i n at e m o st of t h e wat e r-hol di ng vessel s whi c h support container-breeding m o squitoes. The policy of m any landf ills to charge extra for accepting used rubber tires and appliances has created undesirable stoc kpiles in m any backyards or illegal dum ping along isolated ro adsides. Tires can be el i m i n at ed as breedi ng sources by cut ti ng 3-4 l a rge hol es on ei t h er si de, but t

hose m o st l i k el y t o dum p ti r es illegally are least likely to care about cr eating breeding habitat. Tire dum ps create a special problem that can best be dealt with through recycling plants which are now be ing built in m any areas. Re treading operations frequently
sto c k p ile larg e n u m b e rs o f u s edtires th at are awaitin g p r o cessin g . If tires are sto r ed in o p e n su n lit area, th ey will
not be col oni zed by Ae. triseria tu s . Culex pipiens , which will colonize sunlit c ontainers and underground catch basi ns are not a m a jor pest or vect or probl em i n M a ssachuset t s . Cu lex sa lin a r iu s is th e o n l y Cu lex frequentl y t a ken i n m i d t o l at e sum me r hum an bi ti ng col l ecti ons i n t h e Nort heast and i t does not norm a l l y breed i n cat ch basi ns or ot

her cont ai ners. The urban aut ogenous form of C x . pi pi ens (i.e. molestus ) report e dl y bi t e s hum ans (Spi el m an 1973) but out door pest popul ati ons of t h i s form are not wel l document e d i n t h e Nort heast

. In any event , wel l designed and regularly cleaned catch basins should not retainrunoff water. Cities in Massachusetts with old sewer system s still contain m any catch basins which produce Cu lex . The act ual pest st at us of m o squi t o es produced i n catch basins should be well established by each com m

unityprior to control consider ations. New detention and retention basins are frequently built ar ound new m a lls and sim ilar large construc tion site to m anage rainwater and p r o t ect n earb y wetlan d s fro m ru n o ff p o llu tio n an dsiltatio n . In m an y cases th ese b a sin s are b eco m i n g a m o sq u ito probl em ( Cu l ex, Anophel e s, Aedes , and even Co q u illettid ia ). B e t t e r desi gn and m ai n t e nance coul d hel p t o al l e vi at e t h i s growi ng probl em . About 12 y ears ago t h e Asi an ti g er m o squi t o , Ae. al bopi ct us , was accidentally introduced into Texas, presum ably via used tires from northern Asia (Moore 1986) . Since its introduction, this day-active, m an-biting pest and pot enti a l vect or speci es has spread i n t o 17 st at es i n cl udi ng several i n t h e Nort h. It has been found i n Marylan d an d m ay ap p ear in Massach u s etts. Bitin g d e n s ities o f 3 0 p e r m i n u t e alread y h a v e b een rep o rted inTex a s, Lo u i sian a an d Illin o i s. Th is sp ecies is m o st co m m o n in tires b u t will o ccu p y a v a riety o f m an - m a d e

co n t ain e rs. Its co n t ro l is lik ely to b eco me an im p o rtan t p rio rity in th e No rth east with in a few years.VII. STANDARDS FOR M O SQUITO CONTROL

A. St andards for M oni t o ri ng and C ontrol : Pest i c i d e appl i cat i ons i n an IPM program requi re m oni t o ri ng insect populations and com p ari ng data with pre-established thresholds fo r treatm e nt. In addition, post-treatm e nt eval uat i on i s requi red t o ensure th e tr eat m e nt worked as pl anned and di d not have uni nt ended si de-effect s. 1. Larval Popul at i ons: The pri m ary t echni que for l a rval popul at i on count s i s th e di p count . It i s hard t o st andardi ze di ppi ng t echni que but , for th e purposes of th is d o c u m en t, it is assu m e d th at d i p s are tak e n in undisturbed pools (the fi eld person is aware that disturbing the wate r and/or casting a shadow over the water will

cause m o squi t o es t o di ve, th ereby l o weri ng count s) known by th e fi el d personnel t o be t y pi cal of th e breedi ng area being m onitored. For large-scale work , dipping will be done at perm anent, m a rk ed (or easily located) dip stations. For sm all sites such as drainage basi ns and woodland pools, dips will be take n at random throughout the site. Up to twenty dips per site will be taken unless the count for treatm e nt and/or water m a nagem e nt is exceeded with a

sm al l e r num ber of di ps. Speci fi cs for vari ous t y pes of work are gi ven i n Tabl e 17.

a. Larval Identification. Fi el d i d ent i f i cat i on of l a rvae t o genus i s desi rabl e. The fol l o wi ng genera shoul d be recogni zabl e m o st of th e t i m e: Aedes, Anopheles, Coquillettidea, Culex, Culiseta, Psorophora, and Ura n e ta en ia . Program s shoul d rear out suffi ci ent num bers of l a rvae (or i d ent i f y l a rvae t o speci es) to allow correlation between adult m o squ ito species and larval populations. B ecause there m a y be situations where
treatm e nt will depend on the species (as opposed to the genus ) present, program s are encouraged to have a staff

m e m b er train e d in larv al (4 th in star) id en tificatio n b. Pre-control Larval M oni t o ri ng. Larval popul at i ons are m oni t o red t o det e rm i n e whether or
not control i s requi red and, i f so, whether short

- t e rm or l ong-t e rm control i s preferred. C r i t e ri a for wat e r m a nagem e nt i n sal t m a rshes are gi ven i n m o re det a i l i n Appendi x D. Project s shoul d devel op th ei r own cri t e ri a for freshwat e r wat e r

m a nagem e nt work, though som e gui del i n es are gi ve n bel o w under st andards for phy si cal control

.Tabl e 17. Speci fi cs for m oni t o ri ng l a rval (& pupal ) popul at i ons of m o squi t o es for det e rm i n i ng control

. No Treatm e n t Pesticid e W a ter m a n a g e m e n t #Sites fo r larg e-scale wo rk Appl i cat i on Sal t M a rsh <1 per 10 di ps 1+ per 10 di ps 5+ per di p a 1 di p st at i on per 250 acres Freshwater Ground <1 per 5 di ps 1+ per 5 di ps Vari abl e Not appl i cabl e Aeri al <1 per 10 di ps 1+ per 10 di ps Not appl i cabl e 1 di p st at i on per 250 acres

a Num e rous addi t i onal fact ors go i n t o det e rm i n i ng wat e r m a nagem e nt opt i ons for OM W M

.

c. Post-control or post-alteration m onitoring will be conducted as follows:

Treat m e nt Techni que Eval uat i on Si t e s Ti m e Peri od Num b er of Di ps Aerial applications each dip station within two bus iness days. Ten dips Ground appl i cat i ons one of every t e n si t e s wi th i n t w o busi n ess day s Ten di ps W a ter m a nagem e nt each dip station for two years post-alteration Three dips

d. Addi t i onal W a t e r M a nagem e nt R e qui rem e nt s. Project s have an obl i g at i on t o ensure th at al l al t e rat i ons funct i on as i n t e nded w i thout adverse effect s on th e envi ronm ent
. Post -al t e rat i on work for wat e r

m a n a g e m e n t (Ap p e n d i x 4 fo r OMW M ) will also m o n ito r v e g e tativ e re-g ro wth , ch an g e s in fau n aan d n o t es o n whether or not th e hy drol ogy of th e si t e i s as i n t e nded.

e. Pre-hatch W o rk. On occasion, pre-hatc h treatm e nt is desirable. In such cases, the project shoul d have hi st ori cal dat ath at est abl i s hes a pat t e rn of breedi ng at a gi ven si t e . Pre-tr eat m e nt work i s lim ited to Categ o r y IV larv icid es. 2. Adult Populations. No adulticiding program will be conducted on a routine, pre-scheduled basis (i.e. once per week, regardless).

a. Mo n ito rin g fo r Ad u lticid in g Mo n ito rin g Mech an ism Rate to trig g e r ad u lticid in g Light traps Hum a n-biting m o squ ito counts exceed five per night Landing counts Landi ng count rates exceed one per m i nute Com p laint calls W h en com p laint ca lls exceed two per geographical area (th i s area will v a ry b u t assu m e ap p r o x i m a tely o n e sq u a re m ile)

b

. Co n s id eratio n s fo r ad u lticid in g . Ad u lticid e ap p licatio n s fo r m o sq u ito co n tro l req u i re particular care as they are generally m a de wi th rath er broad-spectrum pest i c i d es (for exam pl e, resm ethri n i s ofconcern near fi sh wat e rs) i n areas of hi gh hum an use. Pest i c i d e aerosol s, whi l e an effect i v e t echni que for usi ng

sm al l am ount s of pest i c i d e t o i m pact l a rge num bers of m o squi t o es, al so i n crease concerns over dri f t i n t o non-t a rget areas such as apiaries and organic farm s. As is always th e case, read in g an d fo llo win g th e p e sticid e lab e l is essential. Also, adulticide operators should have a m a p of no-treatm e nt zones with them on their routes and they should be aware of variations in weather conditions (high wind) that would affect, or even cancel, a treatm e nt.

c. Further notes on com p laint calls. Becau se different people co m p lain at different

m o squito population levels, program personnel will conduct la nding counts and/or place light traps within adulticide
zones at i n t e rval s th roughout th e season t o det e rm i n e what m o squi t o popul at i on l e vel s are tr i ggeri ng what l e vel s of

com p l a i n t cal l s . C h roni c com p l a i n t cal l e rs shoul d be checked by conduct i ng l a ndi ng count s and/ or hangi ng l i ght trap s at th e lo catio n o f th e co m p lain er. d. Adul t Ident i f i cat i on. Li ght tr ap m o squi t o es shoul d be sort ed and up t o 100 i ndi vi dual s (random l y sel ect ed from th e l a rger pool ) shoul d be i d ent i f i e d, where possi bl e, t o speci es. If tr ap count s are bei ng

u s ed to m o n ito r water m a n a g e m e n t wo rk , sp ecies id en tificatio n (p articu l arly o f Aedes ) is m o re critical th an if trap s are b e in g u s ed fo r ad u lticid e m o n ito rin g . At least ten m o squitoes from each landi ng count should be identified to species. Com p laint callers should be asked th e tim e of day at which biting occurs.

e. Post-Adulticide Monitoring. Although determining the exact effect of a given adulticide application is difficult, proj ects should increase their efforts to understand the im pact of adulticiding on m o squitoes. Projects should cross-reference com p lain t calls with adulticide applications and record the num ber of calls com i ng i n th e week before an appl i cat i on and i n th e fol l o wi ng week (thi s work m a y be done duri ng th e wi nt er for th e previ ous season). In addi t i on, project s shoul d conduct be fore and aft e r l a ndi ng count s and/ or l i ght -trap count s for ten percent of their adulticide applications. Landi ng counts should be taken w ithin 48 hours pre- and postappl i cat i on at th e sam e l o cat i on both t i m es. Li ght tr ap sa m p l e s shoul d be from th e sam e tr ap and for th e sam e t i m e peri od before and aft e r tr eat m e nt . W h ere possi bl e, non-tr eat ed areas si m i l a r t o th e tr eat ed area shoul d be checked t o det e rm i n e popul at i on tr ends out si de th e spray zone. Projects should keep a log of com p laint calls receive d post-treatm e nt Such com p laints m a y be of nontarget effects such as fish or bird kills, or of hum an exposure to the treatm e nt. W h ile establishing a link between an adulticide application and a specific probl em is very difficult, such com p laints m a y provide insight into the efficacyof th e appl i cat i on or m a y al ert control project s t o probl em s wi th spray equi pm ent , tr eat m e nt t i m i ng and/ or tr eat m e nt

area. C

. St andards for Phy s i cal C ontrol

. Al t e ri ng orel i m i n at i ng m o squi t o breedi ng si t e s range from proper di sposal of t i r es th rough anal y z i ng drai nage sy st em s t o cr eat i ng ent i r e new open m a rsh wat e r m a nagem e nt sy st em s. All m o squito control program s should create a m a p of their area of responsibility on which they have roughl y dem a rcat ed endangered speci es est i m at ed habi t a t s and si gni fi cant habi t a t s as l i s t e d i n th e Natu ral Heritag e Atlas . Thi s shoul d be referred t o before any m a i n t e nance or new work i s done and speci fi c m a ps wi th i n th e At l a s checked when work is taking place near such an area. Any work with such an area, mu st go through NHESP. Fo r th is sectio n Ph ysical Co n tro l refers sp ecifically to alteratio n s to b r eed in g h ab itat to p r ev en t m o sq u ito es from m a tu ri ng t o adul thood. Phy s i cal C ontrol i s di vi ded further i n t o th ree t y pes: So u r ce Elim in atio n : Co m p letely elim in atin g th e b r eed in g site not just th e m o squi t o breedi ng. Source el i m i n at i on i s general l y l i m i t e d t o breedi ng habi t a t s creat ed by hum ans i n non-wet l a nd areas. Source M a i n t e nance: M a i n t a i n i ng pot ent i a l breedi ng sources i n such a way th at m o squi t o es cannot becom e a probl em . So u r ce Red u c tio n : Red u c in g th e ab ility o f an area to b r eed m o sq u ito es. It d i ffers fro m so u r ce m a in ten a n ce in th at th e ex istin g h ab itat is b r eed in g m o sq u ito es wh ereas, if a m a in ten a n ce p r o g r am i s runni ng as desi gned, m o squi t o breedi ng shoul d not occur. Once a source reduct i on project i s co m p leted , it will, in m o st cases, req u i re at least so m e so u r ce m a in ten a n ce in o r d e r n o t to retu rn to bei ng a m o squi t o -breedi ng habi t a t
. Al though th e th ree t y pes of Phy s i cal C ontrol bl end i n t o one another, th ere i s val u e i n recogni zi ng th e di fference, part i c ul arl y bet w een m a i n t e nance and reduct i on. Here the critical issu e is the need to docum ent

m o squi t o breedi ng. W h i l e unwarrant ed di t c hi ng i s not desi rab l e, n e ith er is it d e sirab l e to p r ev en t m a in ten a n ce o f exi s t i ng di t c hi ng t o th e poi nt where m o squi t o breedi ng begi ns i n an area th at has been m o squi t o free i n th e past . It is im p o r tan t to stress th at n o m o sq u ito -co n tro l activ ity th at wo u l d resu lt in th e p e rm an en t lo ss o f tru e wetlan d (as opposed to tem porarily flooded areas resulting from hum an m i sm anagem ent) can be accepted as a standard practice. 1. Source El i m i n at i on.

a. Tires. All m o squito-control program s should have a system in place for contacting depart m e nt s of publ i c works wi th i n th e project so th at th e t i r es can be rem oved. W h ere t i r es are bei ng i n t e nt i onal l y st ored, project s shoul d at t e m p t

t o cont act th e propert y owner and expl ai n th e breedi ng pot ent i a l of th e t i r e dum p. Projects are not responsible for ensuri ng com p liance with tire-disposal regul ations; their sole responsibility is ed u catio n o f p r o p e rty o w n e rs an d n o tificatio n o f ap p r o p r iate lo cal au th o r ities.b. B l ocked drai nage. In th i s si tu at i on, th e assum p t i ons are th at th e st agnant wat e r woul d
not be present i f

not for th e bl ockage and th at th e drai na ge i n quest i on has not been part of an on-goi ng m a i n t e nance program (see source m a i n t e nance bel o w). In th i s case, m o squi t o breedi ng mu st be docum ent e d wi th i n th e bl ocked di t c hi ng for m o squi t o control program s t o re-open th e di t c h (wi thout m o squi t o breedi ng th e di t c h m a y be re-opened by Hi ghway or Publ i c W o rks Depart m e nt s for drai nage reasons).

c. R e si dent i a l probl em s. Such si tu at i ons woul d i n cl ude pool s, refuse dum ps, t i r e tr acks, and other l o cal i zed, m a n-m a de probl em s. As i s th e case w i th t i r e rem oval , project s can onl y advi se propert y owners

o f

th e b r eed in g p o t en tial an d/ o rn o tify th e ap p r o p r iate au th o r ities o f a p r o b l em . d. Drai nage basi n desi gn. A pri m ary t e net of IPM i s t o avoi d creat i ng pest probl em s th rough good pl anni ng. Project s are strongl y recom m e nded t o m a ke avai l abl e t o l o cal agenci es th e speci fi cat i ons for drai nage basi n desi gn l o cat ed i n Appendi x 5. Proj ect s shoul d eval uat e vari ous basi n desi gns for breedi ng pot ent i a l and shoul d educat e l o cal offi ci al s about th e probl em s basi ns can cause. 2. Source M a i n t e nance

a. St orm w at er runoff and di t c h m a i n t e nance. A pri m ary goal of any m o squi t o control program i s t o m oni t o r exi s t i ng drai nage t o ensure th at i t

i s worki ng as desi gned. W i th i n exi s t i ng drai nage, any bl ockage m a y be rem oved regardl e ss of m o squi t o breedi ng. As an exam pl e of th e t y pe of gui del i n es project s shoul d use for this ty pe of work, the standards for the North East M a ssachuset t s M o squi t o and M a rsh R e st orat i on Project are gi ven i n Appendi x F. R ecord keepi ng for m a i n t e nance purposes shoul d be i m proved. Project s shoul d m a i n t a i n at th ei r headquart ers a l i s t of al l drai nage th at i s m oni t o red and m a i n t a i n ed. Thi s l i s t shoul d i n cl ude l o cat i on and approxi m a t e cross-sect i on and l e ngth. Project s shoul d al so m a i n t a i n a record of when and where m a i n t e nance was done. In i n st ances where di t c hi ng has not been m a i n t a i n ed, and no hi st ori cal docum ent a t i on of m a i n t e nance exi s t s , the projects should request a review of the proposed work by DEP’s W a ter Qua lity Certification program to ensure

com p liance. In th e l ong run, project s shoul d devel op pri o ri t y l i s t s for di t c h m a i n t e nance based on th e pot ent i a l for

m o squi t o breedi ng, th e proxi m i t y of hum an act i v i t y , th e ecol ogi cal cost i n reduced wet l a nd benefi t s from th e area bei ng drai ned, and th e rel a t i v e val u e or scarci t y of th e wet l a nds resource affect ed. M a i n t e nance shoul d be based on breedi ng pot ent i a l and ecol ogi cal fact ors.Drai nage basi n m a i n t e nance i s al so i n cl uded wi th i n th i s area. Som e basi ns th at do not produce m o squi t o es when m a intained properly, will becom e breeding sources if left unm ai ntained. Projects should conduct yearly checks of drai nage basi ns t o ensure th at pool i ng wi th i n th e basi n i s not i n creasi ng t o a poi nt where breedi ng m a y occur. In deeper basi ns, i nvasi on by cat t a i l or em ergent grasses m i ght al so creat e breedi ng habi t a t
. Basin ownership and m a intenance responsibility are often difficult to determ in e. Mosquito Control Program s need to rem i nd the appropriate authorities that basin m a intenance is an im portant issue and should be

m oni t o red by th e B u i l d i ng Inspect or’s offi ce or other responsi b l e agency . b. Sal t

- m a rsh Di t c hi ng. It i s general l y not recom m e nded th at th e open di t c h sy st em s be

m a in tain ed as is. h o w ev er, p r o j ects will self-d eterm i n e th e n eed fo r m a in ten a n ce o f ex istin g d itch i n g v e rsu s conversi on t o OM W M , underst a ndi ng th at conversi on i s preferred.

c. W a st e Di sposal . Project s are not responsi b l e for wast e di sposal but th ey can and shoul d

m oni t o r areas known for probl em s wi th ei th er t i r e dum pi ng and/ or i m proper general wast e di sposal , part i c ul arl y where i t bl ocks drai nage. The purpose of th i s work i s not t o get project s i nvol ved i n pol i c i ng dum p si t e s, but rath er t o get th em t o m ove from a passi ve strat e gy of tr eat i ng known t i r e pi l e s t o an act i v e strat e gy of el i m i n at i ng such areas and preventing their return. 3. Source R e duct i on.

a. Open M a rsh W a t e r M a nagem e nt . Open M a rsh W a t e r M a nagem e nt (OM W M ) i s th e preferred t echni que for sal t

- m a rsh source reduct i on. W h en done properl y , OM W M can resul t i n vi rtual el i m i n at i on of breeding without any loss of wetland. Although each proj ect with salt m a rsh will develop its own standards, the
st andards of th e North East M a ssachuset t s M o squi t o C ontrol and W e t l a nds M a nagem e nt Di stri ct are i n cl uded as Ap p e n d i x 4 as g u i d e lin es fo r estab lish i n g an OMW M system th at will co m p ly with all state an d fed e ral reg u l atio n s . New open t i d al di t c h sy st em s are not recom m e nded ex cept as an integral part of an OMW M system
. b. Freshwat er wet l a nds. Source reduct i on i n freshwat e r sy st em s, excl usi v e of exi s t i ng drai nage net w orks, does not have an equi val e nt t o OM W M in salt m a rsh e s. At th is tim e th ere can b e n o stan d a rd s fo r water m a n a g e m e n t with in fresh water system s ex cep t th at an y su ch wo rk mu st b e ev alu a ted b y th e ap p r o p r iate

au th o r ities o n a case-b y -case b a sis. An ad d itio n a l co n s id eratio n is wetlan d s rep licatio n , th e process by whi c h exi s t i ng wet l a nds m a y be al t e red and new wetlands created. W h ile m o squito control projects should not be the authors of such work, they will bei nvol ved i n m oni t o ri ng such areas. Further, recl assi fy i ng som e areas as wet l a nds repl i cat i on si t e s m a y wel l al t e r th e ext e nt t o whi c h wat e r m a nagem e nt work and/ or l a rvi c i d i ng can or shoul d be done. For th i s reason, project s shoul d be m a de aware of al l wet l a nds repl i cat i on project s. As wi th drai nage basi n desi gn, project s shoul d l i k ewi s e devel op a worki ng rel a t i onshi p wi th t o wn Zoni ng B o ards and B u i l d i ng Inspect ors so th at m o squi t o control program s are i n cl uded i n th e revi ew process for wet l a nds re st orat i on, repl i cat i on or creat i on project s.

c. Cattail co n tro l. In o r d e r to p r ev en t in creases in Coquillettidea perturbans, project s shoul d discourage the creation of deep-water (t wo feet p l u s ) cattail m a rsh e s (Drain ag e b a sin s ) in resid e n tial areas. Failin g i n th at , project s shoul d request th at such m a rshes be de si gned so th at wat e r m a y be drai ned from th e m a rsh for a peri od of several weeks i n l a t e sum m e r. D. St andards for B i ol ogi cal C ontrol

. 1. Larvi vorous fi sh. OM W M i s dependent on nat i v e fi sh i m m i grat i ng i n t o th e newl y creat ed di t c h and reservoi r sy st em . Project s shoul d expl ore th e i d ea of st oc ki ng nat i v e fi sh speci es i n deep-wat er drai nage basi ns. 2. Other bi ol ogi cal control agent s . Excl usi v e of th e B t i and Bacillus sphaericus product s (l i s t e d here under pest i c i d es), th ere are no current bi ol ogi cal cont rol agent s avai l abl e for use for m o squi t o control i n Massach u s etts o th e r th an larv iv o r o u s fish . Mo sq u ito co n tro l p r o g r am s in Massach u s etts are n o t research in stitu tio n s and cannot be expect ed t o devel op bi ol ogi cal control agen t s wi thout ext e nsi v e research support

. Shoul d research uncover possi bl e control agent s , project s are encouraged t o experi m e nt wi th th em . E. St andards for publ i c not i f i cat i on, publ i c awareness and educat i on. 1

. Pu b lic No tificatio n . Pro j ects mu st co m p ly with reg u l atio n s fo r aerial ap p licatio n s o f p e sticid es. For truck-m ounted adulticiding, projects should notif y the public through the pr int m e dia, between March 1st and May 1st of each year, as to the areas that m a y be tr eated, the pesticide to be used and a num ber to contact for

m o re i n form at i on or t o request excl usi on from tr eat m e nt
. Al l project s shoul d m a i n t a i n , ei th er at th ei r headquart ers or at a desi gnat e d publ i c l i b rary , a copy of th i s GEIR an d co p i es o f th e lab e ls an d MSDSs o f all th e p e sticid es th ey u s e. it is fu rth e r reco m m e n d e d th at th ey in clu d e copi es of any educat i onal m a t e ri al s th ey have put out
. 2. Publ i c Awareness and Educat i on. As educat i on i s a pri m ary aspect of an IPM program , project s are encouraged t o devel op educat i onal fl y e rs coveri ng such aspects of their work as pesticide use, waterm a nagem e nt , and propert y - owner m o squi t o control

. Fl y e rs m a y ei th er be devel oped i n -house or be obt ai ned from
th e st at e or other agenci es. Exam pl es of educat i onal m a t e ri al s m a y be found i n Appendi x 7. 3. Staff Developm ent. Aside from the pesticide applicator recertification requirem e nts, program s are urged to provide opportunities for staff to increase th eir knowledge about m o squitoes, wetland, and m o squito control. Mem b ership in professi onal organizations, accessing inform ation through university Libraries or the Int e rnet , and devel opi ng good worki ng rel a t i onshi ps wi th fede ral , st at e and l o cal offi ci al s whose t a sks overl ap th at of m o squi t o control are al l good way s t o i m prove th e knowl e dge and perform ance of st aff. F. Standards for EEE m onitoring and DPH liaison. 1. Role of Program s in EEE Surveillance. The M A DPH i n cooperat i on wi th th e Execut i v e offi ce of Envi ronm ent a l Affai r s (EOEA) and th e regi onal

m o squi t o control di stri ct s of east e rn M a ssachuset t s devel oped th e “Vect or C ontrol Pl an t o Prevent East ern Equi ne Encephalitis (1991, currently being revised) . This plan outlines and defines polic y for vector control of m o squitoes that transm it the EEE virus and provides guidance for the coordinati on of state, regional, and local efforts during EEE outbreaks, This plan requires the ac tive cooperation of MCDs in the EEE Risk Area. At clearly defined levels of EEE risk, based upon surveillance data collected by DPH, MCDs are asked to assist DPH in assessing vector species abundance levels and control op tions in their com munities. The coope rative efforts of the MCDs working with DPH helps effect targeted, species -specific vector control when warranted . At the Level of EEE Public Health Em ergency (see Appendi x B ) , th e M C Ds work i n conjunct i on w ith DPH to carry o u t all p h a ses o f th e co n tro l effo rt. 2. Standard Operating Pro cedures during EEE problem

. W h en surveillance data points to increasing leve ls of EEE risk, DPH notifies the SRMCB and regional MCD superintendents. The EEE Surveillance Program inform s MCD superintendents of is olations of EEE in their districts and the districts, in turn, provide feedback to DPH regardi ng population and life stag e indices for critical

m o sq u ito sp ecies. At certain d e fin e d in terim lev e ls o f risk as o u tlin ed in th e “Vecto rCo n tro l Plan ,” MCDs m a y b e asked to increase their ground control larvicide and/or a dulticide applications in re sponse to increased EEE virus
act i v i t y . The SR M C B i s responsi b l e for contract i ng wi th appropri a t e m o squi t o control appl i cat ors i n th e event th at aerial EEE vector control is recom m e nded by DPH.VIII. SUM M A RY AND RECOM M E NDATIONS

A. Legal , Organi zat i onal and Fi scal As pect s of M a ssachuset t s M o squi t o C ontrol The organi zat i onal structure and fundi ng for M a ssachuse t t s m o squi t o control program s, be th ey regi onal or t o wn based, rest s predom i n at el y at th e l e vel of t o wn gove rnm e nt , al though th e st at e l e gi sl at i v e bodi es have a di rect i n fl uences over ei ght of th e ni ne M C Ps’ annual budget s (onl y East M i ddl esex i s not so affect ed). In contrast , th e

o v e rseer o f m o sq u ito -co n tro l activ ity in Massach u s etts is th e State Reclam atio n an d Mo sq u ito Co n tro l Bo ard

. Th is i s a l oose arrangem e nt for del i v eri ng a publ i c servi ce th at i s best appl i e d at a regi onal l e vel

. Lack of control effort i n one t o wn can great l y effect th e effi ci ency of control effort s i n nei ghbori ng t o wns. En ab lin g leg i slatio n h a s b een written in a p a tch w o r k m a n n e r so th at th ere is cu rren tly little co n s isten c y from project t o project . For exam pl e, t o wns i n B a rnst abl e C ount y (and form erl y i n B e rkshi r e) are al l m e m b ers of
th ei r respect i v e regi onal M C project and no i ndi vi dual com muni t y m a y wi thdraw from th e program wi thout changi ng th e l e gi sl at i on as di d C h ap. 119 of th e Act s of 1982 i n th e case of B e rkshi r e C ount y . Thi s provi des an assurance of fiscal and organizational st ability that is lacking in other program s. For exam ple, the Essex County and C e ntral M a ssachuset t s project s both went th rough c onsi d erabl e upheaval s i n m e m b ershi p bet w een 1988 and 1993. Fortunately, the other projects have rem a ined rem a rkably stable ove r the past decade. Maintaining and im proving stability, both in m e m b ership and funding, is a desirable goal. Thi s uncert a i n fi scal pi cture i s further com pounded by th e fact th at al l M C project s i n M a ssachuset t s are seri ousl y under-funded. In other st at es, wi th progressi ve M C program s, th e per capitaexpendi tu re vari es from $2 upward. In Massachusetts, it averages about $0.50 (based on $2 per household of 4 peopl e). In addition, m a ny other st at es provi de suppl em ent a l st at e funds t o encourag e non-chem i cal control effort s and for support i v e research and educational activities. No such state support exists in Massachusetts. W h en supplem ental state support has

com e , it has been for chem ical adultic iding in the wake of EEE threats. To a l a rge ext e nt , fundi ng di ct at es th e control approaches th at can be pursued. IPM , source reduct i on, 1arval control , and adul t control represent th e four m a jor opt i ons i n th ei r order of decreasi ng cost and effi ci ency . Thus, poorl y funded program s are forced i n t o m o re rel i a n ce on l e ss effi ci ent and m o re controversi a l t echni ques. Larger, bet t e r-funded, and st abl e regi onal project s can i nvest i n bet t e r pai d and tr ai ned em pl oy ees, bet t e r surveillance and public education program s, and expensiv e equipm ent such as helicopters which can broaden theopt i ons for safer and m o re effi ci ent l a rval control (e.g., granul ar l a rvi c i d i ng wi th B t i and m e thoprene). Giv e n th e fact th at sev e ral d i fferen t state ag en cies are co n cern e d with m o sq u ito co n tro l activ ities, th e current system of interagency res ponsibility for overseeing MC activities (i.e ., State Reclam ation and Mosquito C ontrol B o ard represent i ng 3 di fferent st ate agencies) is perhaps the best co m p rom i se arrangem e nt . On th e other hand, the level of general support services that projects a nd towns receive from this Boar d seem s to be inadequate. R ecom m e ndat i ons That new and com p rehensi v e enabl i ng l e gi sl at i on be draft e d, revi ewed, appropri a t e l y revi sed, and passed into law, which will bring all MC c ontrol activity in Massachusetts under th e sam e organizational, fiscal and operat i onal gui del i n es. Thi s l e gi sl at i on shoul d provi de for th e fol l o wi ng: 1. The St at e R ecl am at i on and M o squi t o C ontrol shoul d have th e fol l o wi ng personnel :

a. An Execut i v e Di rect or @ approxi m a t e l y $45,000 per y ear b. An Engi neer @ approxi m a t e l y $35,000 per y ear

c. An Ent o m o l ogi st @ approxi m a t e l y $35,000 per y ear Not onl y woul d th i s st affi ng perm i t th e st at e t o conduct research i n t o m o squi t o control , i t woul d provide a team for rapid response to EEE thr eats in com munities that are not m e m b ers of
est abl i s hed M C Ps. Thi s st aff woul d al so provi de servi ces such as i n corporat i ng DEP st orm w at er

m a nagem e nt gui del i n es i n t o M a ssachuset t s M C P Upl a nd W a t e r m a nagem e nt operat i onal procedures. 2. An operat i ons budget , above and bey ond th e norm a l needs of th e SR C M B , for research and devel opm ent
. A m i ni mu m of $50,000 per y ear i s suggest ed. 3. A com p etitive grant fund (funded by the state, adm i nistered by the Execu tive Director of SRMCB and advi sed by an ad hoc panel of out si de expe rt s) t o support IPM rel a t e d research and del i v ery program s wi th i n th e st at e m o squi t o control ent e rpri se. Thi s shoul d provi de support for studi es such as: cost / b enefi t anal y s i s of m o squi t o -control program s; devel opm ent of hum an annoy ance th reshol ds (HAT); i m proved m e thods for m oni t o ri ng and predi c t i ng m o squi t o popul at i on l e vel s ; devel opm ent , eval uat i on, and i m pl em ent a t i on o£ new, non-chem i cal m o squi t o m a nagem e nt t echni ques (e.g., open m a rsh m a nagem e nt and bi ol ogi cal control ) ; m a nagem e nt of pest i c i d e resistance, drift and other use exposures; im p act of MC activities on surface and ground water,and on non-t a rget organi sm s; and th e bi ol ogy and rol e of sel ect ed speci es i n di sease tr ansm i ssi on. 4. The SRMCB should establish a com m ittee to work with their staff to de velop best m a nagem e nt p r actices (BMPs) fo r all asp ects o f m o sq u ito co n tro l, th e resu lts o f th eir wo rk b e in g u s ed to update the GEIR on a regular basis. The co m m ittee should include four m o squito-control superi nt endent s, four represent a t i v es of envi ronm en tal agencies (federal, state or private) and one
at -l arge m e m b er t o serve as chai rperson. Thei r fi rst order of busi n ess shoul d be t o devel op a set of B M Ps for freshwat e r drai nage m a i n t e nan ce for m o squi t o control

. These B M Ps shoul d
est abl i s h stri ct defi ni t i ons for project s i n whi c h th e m o squi t o control exem pt i on from th e W e t l a nds Prot ect i on Act m a y be appl i e d. 5. M C Ps mu st have th e authori t y t o deny request s for m a i n t e nance work th at does not have a

m o squito-control com ponent. Because these reque sts are often m a de by the sam e persons or

municipalities which provide fundi ng to the MCPs, the SRMCB mu st be willing to act as an appeal s board, t o whi c h a request for work m a y be sen t b y an ap p lican t in th e ev en t th e m o sq u ito
control program deni es th e request
. 6

. Lim it m o sq u ito co n tro l activ ity to reg i o n a lly based regi onal m o squi t o control program s whi c h can be organi zed by th e appropri a t e publ i c vot e. The SR M C B shoul d organi ze th e regi onal based

m o squi t o control program s and appoi nt project or di stri ct com m i ssi oners. The SR M C B shoul d select Com m i ssioners from candida tes proposed by authorized Bo ards/individuals from the cities and t o wns of th e m o squi t o control project s or di stri ct s. 7. A fl exi b l e and appropri a t e sy st em of t a x assessm ent whi c h al l o ws for budget s th at are adequat e t o provi de for th e i m pl em ent a t i on of th e m o st cont em porary and l east ri sky strat e gi es for control l i ng

m o sq u ito es. 8. A l e gal sy st em whereby al l m a jor zoni ng and constr uct i on pl ans i n th e C o m m onweal th are revi ewed by th e execut i v e di rect or of SR M C B and th e appropri a t e count y M C di rect or for th ei r pot ent i a l i m pact on m o squi t o popul at i ons and hum an heal th

. B

. Operat i onal Aspect s of M a ssachuset t s M o squi t o C ontrol Operat i onal program s i n M a ssachuset t s coul d l e gal l y be usi ng chem i cal s (approved by EPA and th e Massachusetts Pesticide Board) that are significantly m o re hazardous than those used in current practice. Thissuggests that knowledge and sensitivity fo r the environm ent and hum an safety ar e generally being considered by the exi s t i ng control program s. As al ready i ndi cat ed, fundi ng l e vel s sel dom al l o w project s t o fol l o w th e opt i mum operat i onal course. Despi t e th ese fi scal constr ai nt s, proj ect s have si gni fi cant l y changed th ei r operat i onal m e thods i n recent years toward m o re source reduction work such as the Open Marsh W a ter Managem e nt projects in Essex, Norfol k and Pl y m outh C ount i e s. M o st project s al so use m o re sel ect i v e and envi ronm ent a l l y com p at i b l e l a rvi c i d es such as B t i and m e thoprene. The operat i onal recom m e ndat i ons th at fol l o w are pr edi cat ed on addi t i onal and adequat e fundi ng bei ng available for im plem entation. R ecom m e ndat i ons 1. Al l M C Project s shoul d bui l d th ei r program s around th e IPM strat e gy of keepi ng hum an annoy ance bel o w th reshol d l e vel s as gi ven i n th e St andards of th i s GEIR

. 2. C ontrol m e thodol ogy shoul d be source reduct i on whenever possi bl e and l a rvi c i d al control when i t is not. Projects should work closely with th e DEP water quality certification program and the Natu ral Heri t a ge Endangered Speci es Program t o m i ni m i ze negat i v e i m pact s of source reduct i on t o wet l a nd habi t a t and/ or rare or endangere d species. The m o st target-selective and envi ronm ent a l l y com p at i b l e l a rvi c i d es (e.g., B t i , m e thoprene) shoul d be used whenever possi bl e regardl e ss of cost consi d erat i ons. 3. Sal t m arsh m o squi t o control effort s shoul d em phasi ze OM W M . Al l OM W M proposal s shoul d in clu d e p l an s fo r fillin g m a n y o f th e o l d g r id d itch e s in Massach u s etts salt m a rsh e s wh ich d o n o t funct i on i n a product i v e way and whi c h mu st regul arl y be cl eaned i n order t o prevent breedi ng i n th e d itch e s th em selv es. Th is will g r ad u a lly elim in ate th e co n tro v e rsy o v e r th e co n tin u i n g n eed to clean these ditches and the problem of what to d o with th e resu ltin g sp o il th at is created

. 4. Docum e nt l o cat i on, l e ngth, and cross-sect i on(s) of al l drai nage sy st em s m a i n t a i n ed by th e project and have th at i n form at i on avai l abl e i n an easi l y underst ood form at for publ i c i n spect i on. Ex em p tio n fro m th e p e rm ittin g p r o cess ex ten t s o n l y to th o s e d r ain a g e system s fo r wh ich ad eq u a te historical records of m a in ten a n ce wo rk ex ist. 5. The SR M C B shoul d creat e a l i s t of pest i c i d es approved for m o squi t o control i n M a ssachuset t s . Adulticides should be from Categories III and IV and larvicides should be from Category IV.6. Adulticiding should only be carried out in em ergency situations involving disease threats or pest densities which consistently exceedthe hum an annoyance threshold. 7. For large-scale adulticiding, only ULV-cold fogging should be used. For spot treatm e nt around recreation areas or other areas where public even t s are t o be hel d , port abl e m i st bl owers usi ng perm ethri n as a resi dual pest i c i d e can be used. 8. Aeri al appl i cat i ons shoul d be restri ct ed t o gra nul ar formul at i ons i n areas where dri f t coul d be a si gni fi cant probl em . Som e t i m es som e dri f t i s de sirable so as to reduce the chance of gaps bet w een appl i cat i on swathes. In such cases a l i qui d formul at i on m a y be a bet t e r choi ce. At th i s t i m e l i qui d formul at i ons are al so si gni fi cant l y cheaper, m a ki ng l a rger appl i cat i ons, and m o re effectiv e co n tro l, easier. In creased u s e o f h e lico p t ers fo r aerial larv icid in g in co o r d i n a tio n with
th e use of dri f t

- suppressi on agent s and t echnol ogi es shoul d be encouraged (part i c ul arl y for enhanced larval control in in accessible habitats such as salt m a rshes, wooded swam ps, vernal pool s, et c.). 9. Project s shoul d fi l e a post

- tr eat m e nt report for aeri a l appl i cat i ons wi th th e Pest i c i d e B u reau whi c h gives location and acreage actually treated. The pre-application form s do not always accurately represent what actual l y happened. 10. Chem ical-use reporting needs to be m onitored to ensure uniform ity and accuracy in reporting. Previ ous report s cont ai ned such probl em s as no uni t s are gi ven on th e 1993 th rough 1995 C a pe Cod report for Bactim os (BTI), tw o di fferent EPA regi strat i on num be rs for B act i m os are gi ven i n th e 1993 C a pe C od and C e ntral M a ssachuset t s M C Ps report s , and bri quet s are vari ousl y report e d i n t e rm s of num ber of bri quet s , pounds of bri quet s or pounds of act i v e i ngredi e nt . The Pest i c i d e Bureau should insist that yearly chem ical-use reports be fille d out according to standardized procedures. R e port s shoul d be checked as th ey com e i n t o ensure th at st andardi zed report i ng procedures are followed. 11. Al l pest i c i d e st orage areas shoul d be equi pped w i th sm oke, fi re and securi t y sy st em s. A st andard procedure shoul d be devel oped for th e di sposal of al l i n sect i c i d al m a t e ri al s used i n M a ssachuset t s for m o squi t o control

. The St at e Pest i c i d e B o ard shoul d encourage m a nufacturers of such product s t o m a rket reusabl e cont ai ners. A st andard pr ocedure shoul d be devel oped for th e cl ean-up ofaccidental spills of insecticides. Proper use of absorbent m a terials and the disposal of such

m a terials are necessary. Proper attire during formul ation and application of insecticides should be

m a de m a ndat o ry for al l i ndi vi dual s i nvol ved i n th ese processes. C. Research Needs There i s a need i n th e m o squi t o control process i n M a ssachuset t s for a strong, operat i onal l y focused, research effort i n freshwat e r wet l a nds, excl usi v e of chem i cal appl i cat i on t echni ques. Thi s i s not t o condem n current research efforts, for we know m o re about EEE m o squitoes than ever before, have im proved saltm arsh m o squito
control dram at i cal l y , and have m a de i m provem e nt s i n bot h chem i cal s used and m e thods of chem i cal use over th e past decade. But there is a need fo r research to assess the environm ental im pacts and efficacy of the current MCP p r o g r am s relativ e to th e fresh water en v i ro n m en t. Addi t i onal research on t opi cs such as l ong-t e rm effect s of OM W M , econom i cal l y vi abl e control of Cq

. pert urbans , and m o squi t o control i n endangered speci es h ab itats also req u i re atten tio n . R ecom m e ndat i ons 1. For wat e r m a nagem e nt pract i ces, m oni t o r i m pact s on ani m al s on a case-by -case basi s, dependi ng on th e si t e and est abl i s h veget a t i on tr ansect s t o docum ent changes i n wet l a nd veget a t i on. 2. Devel op a uni fi ed dat abase th at docum en t s m o squi t o popul at i ons on an ongoi ng basi s from regul ar m oni t o ri ng si t e s. Est abl i s h st at e st andards for m oni t o ri ng m o squi t o es and provi de tr ai ni ng t o m o squi t o control project st aff i n dat acol l ect i on and m a nagem e nt
. 3. C onduct com p arat i v e studi es wi th di fferent m a na gem e nt approaches (e.g. pest i c i d e appl i cat i ons vs. wat e r m a nagem e nt ). 4. Devel op a Geographi c Inform at i on Sy st em (GIS) wi th known breedi ng si t e s and areas of h i sto r ical water m a n a g e m e n t activ ities. 5. Qual i f y si t e s on th e basi s of need for control , based on breedi ng (pot ent i a l or actual ) , m o squi t o sp ecies, p r o x i m ity to h u m an activ ity, lev e l an d typ e of hum an act i v i t y , and t y pe of wet l a nd habi t a t affected. 6. C r eat e an ongoi ng research part nershi p wi th NHE SP t o docum ent wet l a nd t y pes, et c.. M o squi t o C ontrol Project s have knowl e dge and expert i s e a bout wet l a nds th at coul d be i nval u abl e t o NHESP.IX. W R ITTEN COMMENTS ON GEIR NOTE: CONTACT THE STATE RECLAM ATION AND M O SQUITO CONTROL BOARD TO OBTAIN COPIES OF THESE DOCUMENTS

A. C o m m e nt s on Not i ce of Project C h ange (1996). B

. C o m m e nt s on Spri ng 1997, R ough Draft

. C

. C o m m e nt s on Fi nal R ough Draft (1997-98).

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. B

. Jr. and A.H. Dao. Pul m onary di rofi l a ri asi s : a di agnost i c chal l e nge. South. M e d. J. 77,372 (1984). Ai zawa, H. M e t abol l c M a ps of Pest i c i d es, Academ i c Press, New York (1982). Allo , A.Y., A. Isaq an d I.F. Do lfin i. Field trial o n th e im p act o f Oreochromis sp ilurus spilurus on m a l a rl a tr ansm i ssi on l n Northern Som a l i a . W HO/V8C 85,910 (1985). Am brose, A.M

. and D.J. R obbi ns. C o m p arat i v e t oxi c i t y of py reth ri ns and al l e th ri n. Fed. Proc. 10,276 (1951). Anderson, J.F. and S.L. R i ngo. Ent o mopht hora aquat i c a sp. n. i n fect i ng l a rvae and pupae of fl oodwat er m o squi t o es. J. Invert . Pathol . 13,386-393 (1969). Anderson, J.R ., D.E. Egert e r and J.O. W a shburn. The bi ol ogy and bi ol ogi cal control pot ent i a l of Lambornel l a cl arki (C i l i ophora: Tetr ahy m eni d ae), an endoparasi t e of th e W e st ern tr eehol e m o sq u ito , Aedes sierrensis . Proc. C a l i f . M o sq. Vect or C ontrol Assoc. 54,149 (1986). An d r ead is, T.G. an d L.A. Mag n a relli. Eryni a aquat i c a in a salt-m a rsh m o sq u ito , Aedes cant at or . J. Invert. Pathol . 42,277-279 (1983). Arnott, J.J. and J.D. Edm a n. Mosquito vectors of dog heartworm , Dirofilaria Lm m itis in W e stern M a ssachuset t s . M o sq. News 38,87 (1978). Ax tell, R.C. Prin cip l es o f in teg r ated p e st m a n a g e m e n t (IPM) in relatio n to Mo sq u ito Co n tro l. Mo sq . News 39,710 (1979). B a l l i ng, S.S. and V.H. R e sh. Arth ropod com muni t y res ponse t o m o squi t o control reci rcul at i on di t c hes i n San Franci sco B a y sal t m a rshes. Envi ron. Ent o m o l

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### APPENDIX A

GENERAL ENVIRONMENTAL IMPACT REPORT 1996 QUESTIONNAIRE MASSACHUSETTS MOSQUITO CONTROL PROGRAMS

NOTE: CONTACT THE STATE RECLAMAT ION AND MOSQUITO CONTROL BOARD TO OBTAIN COPIES OF THIS DOCUMENT

.APPENDIX B DPH EEE RISK ASSESSMENT, RISK CATEGORIES, STRATEGY FOR VECTOR CONTROL (from the Vector Control Plan to Prevent EEE)

VI. RISK ASSESSMENT The potential risk for EEE disease in humans is cate gorized into one of four levels according to an assessment of EEE surveillance data from the current and previous year. The risk levels are (1)Low (2)Moderate (3)High and (4)Public Health Emergency. Under Risk Leve ls 2, 3 and 4, the character ization of risk includes a definition of areas of concern. The c oncept of "area of concern" is importa nt in defining the magnitude of the EEE risk and selecting appropriate intervention options. There are three components within the conceptual construct of area of concern: study area, risk area and treatment area. (1) The study areais the geographical area where mo st human and equine EEE cases in Massachusetts have occurred. This area is shown in Figure 3 and includes Plymouth, Norfolk, Suffolk, Bristol, Middlesex and Essex Counties. Personal protection measures are emphasized in this area through a public information campaign that intensifies at each level of risk. (2) The risk areais the geographical area where most of the human EEE cases have occurred. This area is shown in Figure 4 and includes Plymouth, Bristol and Norfolk Counties, and parts of Middlesex and Suffolk Counties. Vector control e fforts may be implemented by state agencies or Regional Mosquito Control Districts within this area. Vector control efforts may be extended outside of this area, if surveillance data i ndicate the probability of multiple human EEE cases occurring outside the area of hi storical disease prevalence. (3) Treatment areas are defined by EEE surveillance data and ar e used to guide vector control efforts. The basic cell is defined by a mosquito trap site and is approximately 100,000 acres. These treatment cells are calculated to be the set of "best-fit" polygons that represent the areas around trap sites. The area for treatment will be define d by the GIS polygon inclusive of all towns with more than 20% of their area with in the unit. Vector control intervention will be dependent upon viral isolation from mosquito pool s trapped at the DPH site. The treatment area for a positive EEE virus isolation from a horse or human is defined by a circle a pproximately 2 miles in radius around the case. Within a treatment area, larviciding is recommended in areas where significantlevels of vector species larvae are present, a nd treatment would be expected to reduce adult emergences in proximity to large numbers of people. Adulticiding of a treatment cell is recommended if predetermined risk indices are met and significant numbers of vector species adults are present.

At a Moderate or High level of EEE risk, vector control is cons idered within an area following identification of EEE virus in the e nvironment. Following a positive finding supplemental surveillance is done to assess the need for a vector control intervention. Additional trapping will be implemented in the treatment area to determine the age structures and populati on abundance of vector species. Larval surveys may also be initiated after significant rainfall events. EEE occurs disproportionately by area within eastern Massachusetts. The human cases of EEE by county have been 25 in Plymouth, 19 in Norfolk, 13 in Middlesex, 9 in Suffolk, 5 in Bristol, 1 in Essex, 1 in Barnstable, and 1 in Hampden. A disease prevention strategy must re spond to this disproportionate distribution of risk by providing supplemental mosquito control funding (and/or st ate or federal assistance delivered through independent contractors) for high risk areas and by coordinating efforts among Mosquito Control Districts that share common risk areas. The epicenter of EEE appears to be the contiguous area where Pl ymouth, Norfolk and Bristol Counties join. This area should be the primary target of coordinated mosquito control efforts under the direction of a state office. In the event that fiscal, sta ff, and equipment resources available to regional mosquito control districts are insufficient, the state must be prepared to assist in the effective control of mosquitoes to help prevent or minimize human EEE cases.RISK CATEGORIES (1) LOW - A LOW LEVEL OF EEE RISK exists if all of the following conditions are met: Current Season 1. EEE virus isolates in Cs.melanura <10 2. Population of Cs. melanura below long-term mean Previous Season 1. No human or horse cases 2. Cs. melanura below long-term mean 3. EEE virus isolates <20 At this level surveillance activitie s are routine and supplemental control efforts are not recommended. Mosquito control efforts should be standard in accordance with established plans for integrated pest management (IPM). IPM is an ecologically based strategy for managing insect populations with the goal of keeping pest levels below predetermined threshold levels. Mosquito Control District (MCD) IPM programs may include source reduction, ground or truck spray adulticide, larvicide, a nd other control activities in response to human annoyance thresholds (HATs) as determined by the MCDs operating under the State Reclamation and Mosquito Control Board.

(2) MODERATE - A MODERATE LEVEL OF EEE RISK exists if any of the following conditions exist: Current Season 1. EEE virus isolates from Cs. melanura >10 2. Cs. melanura populations approaching long-term mean 3. 1-2 presumptive or confirmed horse cases Previous Season 1. 1-2 human cases or 2-4 horse cases 2. Cs.melanura population above the long-term mean 3. EEE virus isolates from Cs. melanura >20 At this level, mosquito control interventions should be directed only against those species suspected as epidemic vectors (capable of EEE viru s transmission to humans). Regional mosquito control efforts should be intensified only in EEE virus positive treatment areas. These efforts may include larv iciding and ground or truck spray adulticiding based upon surveillance data that indicates significant larval and/or adult popula tions of bridge vector species.(3) HIGH - A HIGH LEVEL OF EEE RISK exists if any of the following conditions exist: Current Season 1. Confirmation of 1 human case 2. 3 or more presumptive or confirmed horse cases 3. Cs. melanura population above the long term mean and MIR in Cs.melanura >1 4. EEE virus isolate from bridge vector species Previous Season 1. 2 or more confirmed human cases or 5 or more presumptive or confirmed horse cases. These indices trigger intensive su rveillance of bridge vector species and recommendations for state-funded vector control interventions which may include ground or targeted aerial larviciding and/or adulticiding. Treatments would be undertaken only in EEE virus positive treatment areas, defined by EEE viru s isolates and horse or human cases, as surveillance of bridge vector popul ations indicate.

(4) PUBLIC HEALTH EMERGENCY - DPH will forward a recommendation immediately to the Governor’s Office to declare a PUBLIC HEALTH EMERGENCY in th e event that any of the following conditions exist: Current Season 1. 2 human cases are confirmed 2. More than 10 horse cases are confirmed Surveillance data indicating that multiple hum an cases of EEE will occur without intervention These criteria will be considered sufficient for a r ecommendation that an emergency be declared, if they occur at a time when seasonal and biol ogical conditions present a continuing hi gh risk of EEE human disease. The declaration of an Emergency may trigger state supported mo squito control efforts using wide area aerial application of mosquito larvicide or adulticide. A recommendation for a wide area aerial adulticide application will be made only if surveillance data indicate a risk of multiple human cases and biological c onditions are favorable for continuing risk. When such control strategies are recommended, treatment areas will be defined by DPH surveillance data. Areas targeted for aerial pesticide application will immediately be notified and all media sources utilized to alert residents to the timi ng and scope of the application. Envi ronmental monitoring will be done before and after treatment and rare and enda ngered species habitat excluded from the spray zone in affected areas. In addition a 500-1000 foot setback will be observed when sp raying around water bodies. The objective of this option is to cause a significant reduction in all species capable of EEE transmission. This inte rvention is successful if thetarget species are temporarily reduced th ereby interrupting the amplification of the virus within its avian reservoir. The timing of this late season option is critical and is intended to be a one-time intervention.

VII. STRATEGY FOR VECTOR CONTROL A vector control plan must be safe, economical, minimize environmental effects, and minimize the risk of human EEE disease. To achieve these ends, the plan must be, to the maximum extent possible, geographically and vector species specific. Vector cont rol measures are chosen according to sp ecies, seasonal and climatic conditions, and vector life stage indices.Three options will be available for vector control: larviciding; targeted small scale adulticiding; and widearea aerial adulticiding; with specific activities chosen by analysis of surveillance data. Treatment areas will be defined by mosquito trap sites and/or human/equine case locations. Within a treatment area, the use of larviciding or adulticiding interventions will be guided by additional field information and surveillance data to limit the area of intervention to the extent possible, taking into account the uncertainty of risk data. All state supplemented vector control interventions will be done under the author ity of Regulation 304-CMR. Section 50.08 (3)(a). The number of mosquito species that potentially coul d serve as epizootic vectors of EEE is extensive; however the three species most often thought to be responsible for human and equine infection are Coquillettidia perturbans , Aedes vexans and Aedes sollicitans (Tsai 1991). Recent studies suggest that Anopheles species and Culex salinarius should also be considered as epidemic EEE vect ors (Edman et al 1993, Vaidyanathan et al. 1997). An historical analysis of the epid emidology of EEE in Massachusetts and mosquito abundance and isolation data indicate that Ae. vexans , Ae. canadensis and Cq. perturbans are likely vectors involved in human disease transmission in Massachusetts. Ae. sollicitans may also be a vector for cases locat ed closer to the coast, and may be targeted in areas where known human and/or equine cases have occurred. Cq. perturbans , a permanent water species, breeds in cattail marsh areas, common in the disturbed sections of wetlands. This species has one ge neration per year, emerging by mid J une and reaching p eak populations by early to mid July. An aggressive human biter, Cq. perturbans presents a difficult contro l problem because its larvae develop attached to the roots of emergent vegetation in permanent marsh areas. The insect growth regulator methoprene in the form of slow release Altosid formulations has proven to provide effective larval control of this mosquito (Sjogren et al. 1986). This chemical is relatively nonpersistent in the environment and exhibitsmorphological rather than direct toxic action by interfering with larval development. Aedes vexans, Aedes sollicitans , and Aedes canadensis , are reflood mosquitoes whose abundance levels are directly related to rainfall and floodw ater or moon tide events sufficient to flood intermitten tly flooded oviposition areas. All of these species may exhibit peak populations mid to late summer concurrent with peak EEE virus activity in birds and may be treated at the larval stage using the biological control product, Bacillus thuringiensis

var. israelensis (Bti). The success of such applications, may be hampered, however, by the small treatment window available due to rapid larval development and by the di fficulty of application through the dense canopy and thickunderbrush of late summer. Bti is a natural microbial agent toxic to most mosquito and blackfly larvae. It is nontoxic to bees but some mortality to other Diptera has occurred at mosquito-c ontrol application rates. In all EEE vector interventions standardized larval surveys will be conducted pre and post application. Aedes vexans is the most predominant summer reflood mosquito in Massachusetts. The appearance of this species is dependent on the frequency and spacing of major ra ins. Broods have been observed from the latter part of June throughout the summer and into the fall. Although the window for effective larval treatment is narrow due to the rapid development of this species, Bti applications have been used successfully for control. Aedes sollicitans breeds in the high salt marsh that is normally only flooded by moon tides at the full and

new moon. Aedes sollicitans is an aggressive biter know to travel great distances from its breeding habitat. This species can be effectively controlled with Bti and treatment is made easier by the predictability of its life cycles. Aedes canadensis is primarily a univoltine species that appear s from late spring through mid summer. A second brood can develop in early fall if rainfall is sufficient. These mosquitoes develop in temporarily flooded woodland depressions and vernal pools th at are often inaccessible, particularly late in the summer, due to heavy underbrush making ground control difficult if not impossible to accomplish. Due to the heavy tree canopy and dense underbrush of this habitat, aerial larval control of Aedes canadensis is also very difficult. Anopheles mosquitoes inhabit permanent water, and may be found along the edges of slow moving streams. In the latter part of the summer they may also be found in temporary pools and puddles caused by summer rainfall. Culex salinarius is classified as a permanent water species. This species is multivoltine with peak populations occurring late in summer. Cx. salinarius is an active human biter and although mammalophagic, it is more likely than other potential epidemic species to feed on birds thus increasi ng its chances of a playing a role in EEE virus transmission (Vaidyanatha n et al 1997). The larvicide Bacillus sphaericus has been found to be effectiveagainst Culex species. Bacillus sphaericus is a naturally occurring bacterium with the same mode of action as Bti but with an even more narrow toxicity range. This larvicide is more effective than Bti in the highly organic water favored by Culex species. The spores of this bacterium ar e slowly removed from the water column and B. sphaericus may undergo limited recycling in certain environmen ts thereby increasing its availability to target organisms. Granular formulations of B. sphaericus have been found to work effectively against Anopheles species (Arrendondo et al. 1990). Altosid formula tions have also been used successf ully as larval control agents. Small-area, targeted, ground or aeria l adulticiding with ULV malathion or resmethrin may also be utilized if specific risk conditions are met. This effort will be ai med at all potential vector species in the target area where population and life stage studi es indicate treatment is required. Wi de-scale aerial adulticiding may only be employed during a public health emergency if it is determined that use of such treatment is needed to prevent further human disease transmission. An effective adulticide provides a sufficient reduction in vector species such that there is insufficient time for reinfection of a subsequent brood of vector species be fore the end of the mosquito season. Late season risk following a wide area intervention is usually limited by lack of virus availability in avian species, the low probability of significant numbers of infectious human biting mosquitoes surviving, and cooler weather that limits the activity of mosquitoes. All state supplemented aerial adulticide treatments w ill use ULV malathion. A comprehensive review of aerial applications of insecticide fo r mosquito control concludes that UL V applications are efficacious, cost effective and can be used effectively over dense foliage or open housing (Mount et al. 1996). Malathion has been chosen because of its effectiveness ag ainst adult mosquitoes and its relative safety for humans and other vertebrates (Edman and Clark 1990). The efficacy of all adulticiding treatments will be de termined by a comparison of pre and post-spray DPH trap site mosquito abundance levels.Literature Cited Arrendondo-Jimenez J.I., T. Lopez, M.H. Rodriguez, and D.N. Bown. 1990. Small scale field trials of Bacillus spaericus (strain 2362) against Anopheline and Culicine mosquito larvae in southern Mexico. J. Am. Mosq. Control Assoc. 6(2):300-305. Edman J.D. and J.M. Clark 1990. Draft generic environmen tal impact report on mosquito control in Massachusetts Edman J.D., R. Timperi, and B. Werner. 1993. Epidemio logy of Eastern Equine Ence phalitis in Massachusetts. J. Florida. Mosq. Control Assoc. 64: 84-96. Komar, N. 1997. Reservoir capacity of communally roosti ng passerine birds for eastern equine encephalitis (EEE) virus. Ph.D. diss., Department of Tropical Public Health, Harvard School of Public Health. Mount, G.A., T.L. Biery and D.G. Haile. 1996. A review of ultralow-volume aerial sprays of insecticide for mosquito control. J.Am. Mosq.Control Assoc. 12(4):601-618. Sjogren, R.D., D.P. Batzer and M.A. Juenemann. 1986. Evaluation of methoprene, temephos, and Bacillus thuringiensis var. israelensis against Coquillettidia perturbans larvae in Minnesota. J. Am. Mosq. Control Assoc. 2(3):276-279. Tsai, T.F. 1991. Arboviral infections in the United States. Infectious Disease Clinics of North America. 5: 73- 101. Vaidyanathan, R., J.D. Edman, L.A. Cooper, and T.W. Scott. 1997. Vector competence of mosquitoes (Diptera:Culicidae) from Massachusetts for a sympatric isolate of eastern equine encephalomyelitis virus. J. Med. Entomol. 34:346-352. Villari, P., A. Spielman, N. Komar, M. McDowell, and R.J. Timperi. 1995. The economic burden imposed by a residual case of eastern encephalitis. Am J. Trop. Med. Hyg. 52: 8-13.

### APPENDIX C

GENERAL ENVIRONMENTAL IMPACT REPORT PESTICIDE LABELS AND MSDS MASSACHUSETTS MOSQUITO CONTROL PROGRAMS

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.

### APPENDIX D

GENERAL ENVIRONMENTAL IMPACT REPORT NORTHEAST MASSACHUSETTS MCP STA NDARDS FOR OPEN MARSH WATER MANAGEMENT

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.APPENDIX E STORMWATER MANAGEMENT

The following is a brief summary of information relevant to mosquito control found in the three state publications: Stormwater Management. Volume One: Stormwater Policy Handbook. (March 1997) Stormwater Management. Volume Two: Stormwater Technical Handbook. (March 1997) Both prepared by the Massachusetts Department of Environmental Protection and the Office of Coastal Zone Management. Massachusetts Erosion and Sediment Contro l Guidelines for Urban and Suburban Areas. Prepared by the Franklin, Hampden and Hampshire Conservation Districts and available through the Department of Environmental Protection. These documents should be referenced di rectly for more detailed information. The two concerns addressed by these publications are water quality (pollutant s) and water quantity (flood control). They are primarily concerned with preventing pollutants from flowing into waterways and wetland systems, and with controlling runoff from developed sites. For mosquito control, ther efore, the regulations are generally not directly applicable (except in rare cases of new construction) but come into play when MCPs are asked to conduct mosquito control within these constructed systems. This results in the odd situation where Best Management Practices for stormwater management are not evaluated for their mosquito-breeding potential. However, failing to address mosquito control in the desi gn phase may result in a larger-than-necessary number of stormwater management systems that contribute to mosquito problems. In endemic eastern equine encephalitis areas, creating additional breeding habitat for bridge (bird-to-human) vectors such as Cq. perturbans or Ae. vexans is unwise. Wet (Retention) Basins and Constructed [Stormwater] Wetlands may do precisely that. A significant limitation of the handbooks for mosquito control is that they discuss new construction of manmade systems only. Maintenance of existing and/or natural systems is not discussed. The Erosion and Sediment Control Guidelines should be referred to for information about working in and around existing drainage though even here the issue of maintenance within the existing channel is not discussed. Four issues regarding stormwater management exis t for MCPs and are addressed in order of importance (most important first).1. The expectation that MCPs will maintain drainage systems even when MCP actions did not cause the problem (road sand into a stream). Standard #9 of the “Stormwater Management Form” (page 1-11 of the Policy Handbook), relates to the Operation/maintenance plan for control designs. Although th is particular form is optional, the requirement for a maintenance plan should not be. Where MCPs will be expect ed to monitor for mosquito breeding, they should have access to the maintenance plan for the st ormwater system in question and shoul d be able to request maintenance onsite where mosquito breeding is caused by a breakdown in the system’s operation. Suggested maintenance requirements for each BMP are given in the Technical Handbook. MCPs should also be able to request system alterations in the event a system is continually breeding mosquitoes. Where maintenance responsibility is clear-cut, maintena nce work should be done by the responsible party. Unfortunately, the vast majority of drainage channels ha ve no official maintenance plan and MCPs have routinely assumed or been assigned responsibility for maintenance. In these cases, MCPs should, wherever possible, adhere to the maintenance requirements as given for the BMP that most closely describes the system in question. In most cases this will be the Drainage Channel. 2. The erosion and sediment control standards relating to (exempted) maintenance work done by MCPs. Despite the fact that MCP maintenance work is exempted from the Wetlands Protection Act, the best interests of the MCPs are served by minimizing disruption during maintenance work. Temporary erosion and sediment controls shoul d be used when necessary. Ve getation bordering the channels should be left as undisturbed as possible. Again BMPs for maintenance in existing systems should be developed. 3. System design and the extent to which mosquito breeding is considered prior to construction. BMPs for stormwater management in urban and s uburban areas must include some consideration of mosquito-breeding potential. That the current publication does not is an indication of the need to improve communication between mosquito control and other agencies invol ved in stormwater mana gement. The best place to practice mosquito control in manmade drainage systems is in the design phase. Clearly there is cause for concern over the BMP Constructed [Stormwater] Wetlands, where pools ranging from 6 to 18 inches deep are desired

.4. New construction by MCPs. New drainage construction is not exempted from the Wetlands Protection Act and MCPs should refer to the policy and technical handbooks when designing any new work.

### APPENDIX F

GENERAL ENVIRONMENTAL IMPACT REPORT NORTHEAST MASSACHUSETTS MC P STANDARDS FOR DITCH MANAGEMENT

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### APPENDIX G

GENERAL ENVIRONMENTAL IMPACT REPORT EDUCATIONAL FLYERS REGARDING MASSACHUSETTS MOSQUITO CONTROL PROGRAMS

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### APPENDIX H Preparer Qualifications: George D. Christie CHRISTIE MOSQUITO CONTROL 36 Ewing Road North Kingstown, RI 02852-2020 Tel. (401) 885-7055 FAX: (401) 885-0877 E-Mail: chripest@ids.net EDUCATION : MS, Entomology, U. of California, Riverside, CA June 1984 BS, Entomology, Cornell University, Ithaca, NY Jan. 1981 Continuing Education: Courses in Environmental Planning and Community Development, Dept. of Community Planning, URI 1987-88 EXPERIENCE : Director of the Portsmouth Vector Control Program (14 years), and of mosquito control programs for Tiverton (13 years), Warren (11 years), Bristol (9 years), Lincoln (8 years), and Westerly (5 years). Currently assisting Warwick Mosquito Control Program (12 years). Mosquito Control Consultant for Nantucket , MA 1990 - 1993, 1996 - 1998. Have designed and marketed elementary-school-level classes in Entomology. Assisting Warwick in implementation of city-wide integrated pest management program 1993-1995.

MEMBER : American Mosquito Control Association 13 Years Northeastern Mosquito Control Association 13 Years Member, Board of Directors: 1994-1997 Entomological Society of America 7 Years

### EDITORIAL EXPERIENCE : Editor: Northeaster . The newsletter of the Northeastern Mosquito Control Association. SELECTED PUBLICATIONS : Christie, G. D. 1995. Guidelines for the use of pesticides on cityowned property . Warwick, RI. 54 pp. Christie, G. D. 1993. Business and political skills in mosquito control. Wing Beats . 4(3): 17-18. Christie, G. D. 1992. Non-toxic bait trapping for yellow jackets. Pest Control 60(5): 30-32. Christie, G. D. and R. A. LeBrun. 1991. Culiseta minnesotae and further notes on Aedes aegypti in Rhode Island. J. Am. Mosq. Control Assoc . 6: 742. Christie, G. D. 1990. Salt marsh mosquito control in Portsmouth, Rhode Island. J. Am. Mosq. Control Assoc . 6: 144-147. MOSQUITO CONTROL TALKS ( all talks at the Annual Meeting of the Northeastern Mosquito Control Association unless otherwise noted) 1996 Information on a Fungal pathogen of Aedes canadensis in Vernal Pools. Mosquito Control through Marsh Restoration in Portsmouth, RI 1995 Killer Pathogen, Probably Fungus, appears in Bristol, Rhode Island 1994 Community-level Application of IPM for Medically Important Arthropods 65th Annual meeting, Eastern Branch, Entomological Society of America 1993 When the Edge Meets the Middle: Mosquito Breeding during Intermittent Tides Open Marsh Water Management on Nantucket 1992 Reaching out for Resource Tools and Development Altosid Pellets in Nantucket 1991 Report on Mosquito Control in Rhode Island Monitoring Mosquito Populations for Eastern Equine Encephalitis in 1991 in Rhode Island 1990 Encephalitis in Tiverton, Rhode Island 1989 Open Marsh Water Management in Portsmouth, RI 55th Annual Meeting, American Mosquito Control Association 1987 Private [business] Mosquito Control Endeavors 1986 Overview of Mosquito Control in Portsmouth, RI.