# Best Management Practices

for Integrated Mosquito Management

American Mosquito Control Association

December 2, 2009OVERVIEW OF INTEGRATED MOSQUITO MANAGEMENT

Integrated Pest Management (IPM) was first conceive d as a means of achieving sustained, effective cont rol of agricultural pests through concomitant employment o f a wide range of control methodologies. IPM has be en in widespread usage for many years and its success as a general strategy has led to usage of the term to describe an increasing number of approaches to control strategi es – often leading to misunderstanding of its actua l conceptual framework. In order to clarify the conce pt in terms of its relationship to the unique natur e of mosquito prevention/control methodologies, we will use the term Integrated Mosquito Management (IMM) i n lieu of IPM.

Integrated Mosquito Management is a comprehensive m osquito prevention/control strategy that utilizes a ll available mosquito control methods singly or in com bination to exploit the known vulnerabilities of mo squitoes in

order to reduce their numbers to tolerable levels w hile maintaining a quality environment. Integrated mosquito management methods are specifically tailored to saf ely counter each stage of the mosquito life cycle. Larval control utilizing natural biological control method s, water sanitation practices, and water or vegetat ion management or other types of source reduction measu res where compatible with other land management use s, are prudent mosquito management alternatives - as i s use of EPA-registered larvicides and adulticides. When

source elimination or larval control measures are n ot feasible or are clearly inadequate, or when face d with imminent mosquito-borne disease, application of adu lticides by certified applicators trained in the sp ecial handling characteristics of these products may be n eeded. Adulticide products are chosen based upon th eir demonstrated efficacy against species targeted for control, resistance management concerns and minimiz ation of potential environmental impact. IMM does not emphas ize mosquito elimination or eradication.

Full implementation of modern-day IMM entails signi ficant expenditure of resources that may be beyond the capabilities of many mosquito control programs, par ticularly in light of collapsing state, county and municipal budgets. IMM requires a thorough understanding of m osquitoes and their bionomics by control personnel; careful inspection and monitoring for their presenc e and conditions favoring their development; and pr evention of oviposition and human/mosquito contact through e ffective public education, sanitation and facility maintenance. All mosquito control programs should strive to employ these IMM components to the extent possible, but resource availability may limit what any individual program can do.

In IMM programs, all intervention measures are driv en by a demonstrated need based on surveillance dat a and action thresholds. Applying mosquito larvicides or adulticides on a pre-determined schedule absent a documented need is not acceptable practice in any I MM program.INTRODUCTION

Since the need for mosquito control was recognized in the early twentieth century, increased knowledge of mosquito biology has driven the formulation of a va riety of methodologies designed to successfully red uce both mosquito nuisance levels and mosquito-borne disease transmission. As the technologies and knowledge ba se from which these methodologies were derived have ma tured, they have been increasingly seen as mostly complimentary or synergistic in nature, providing o ptimal control as part of an overall strategy. This has ultimately evolved into a strategy termed Integrate d Mosquito management (IMM). IMM has been developed to encourage a balanced usage of cultural and insectic idal methodologies and habitat manipulations in ord er to minimize adverse environmental impacts. IMM is know ledge-based and surveillance-driven, and when prope rly practiced is specifically designed to accomplish th e following:

1. Protect human, animal and environmental health.

2. Promote a rational use of pesticides.

3. Reduce environmental contamination to soil, ground water, surface water, pollinators, wildlife and endangered species.

4. Utilize natural biological controls to conserve and augment other control methods.

5. Use target specific pesticides to the extent possib le.

6. Emphasize the proper timing of applications.

7. Minimize pesticide resistance problems.

The circumstances necessitating formation of a mosq uito control program, however basic, are unique for each jurisdiction in terms of available resources, topog raphy, hydrology, and the bionomics of the mosquito species to be controlled. For this reason, considerable jud gment must be exercised in allocation of limited re sources to extract the maximum benefit for both the citizenry and the environment. It must be emphasized that pro gram funding and other extrinsic factors will dictate th e extent to which individual programs can implement the Best Management Practices (BMPs) described herein.

To assist in this calculation, the following docume nt will outline a series of BMP program elements th at constitute a fully integrated approach to mosquito management. These BMPs should be viewed as minimums that should be performed in concert with any genera l or individual National Pollution Discharge Elimin ation System (NPDES) permits that might issued for mosqui tocide use in accordance with the Clean Water Act (CWA) requirements.

The extent and manner to which control agencies exe rcise these BMPs should be ultimately based on the best professional judgment of district/agency personnel, often undertaken in consultation with local health and government authorities in addition to resources ava ilable. It is important to emphasize that adherence to these BMPs to the maximum extent practicable is to be con sidered the necessary minimum to undertake or perfo rm for purposes of regulatory compliance with general or individual NPDES permits for mosquitocide use.Best Management Plans for Mosquito Management

Best Management Practices (BMP) should form the fun damental approach to mosquito management for all mosquito control programs. It is acknowledged that individual agencies/entities charged with mosquito management responsibilities may not have the resour ces to practice all of the specific sub-elements di scussed herein. Nevertheless, agencies should strive to adh ere to these BMPs to the maximum extent practicable , given resource availability. Programs are encouraged to m aintain documentation as to how they intend to empl oy the 9 BMP components listed below.

1. Surveillance – Should be the backbone of all IMM programs. Iden tifies problem species and population

trends in order to direct and evaluate control meth ods.

a. Visually check jurisdiction for potential large-sca le larval habitat and larval populations themselves that could contribute to unacceptable ad ult mosquito populations and determine if larval control is appropriate within resource const raints.

i. Rural - swamps, salt & freshwater marshes, woodland pools, flooded fields/ pastures, roadside ditches, storm water retention ponds, tree holes, rice fields, etc.

ii. Urban - flower pots, tires, trash containers holdin g water, gutters, tree holes, septic ditches, roadside ditches, lawn swales, non-functio nal swimming pools, stagnant bird baths, street catch basins, junk yards, depressions in tarp covers, etc.

a. Determine population levels of adult mosquitoes usi ng professionally acceptable techniques, including public complaints or landing rate counts (if appropriate), to establish needs for action.

b. Determine if problem species are peridomestic. Peri domestic mosquito species oviposit primarily in containers around human habitation. Their presen ce as the primary pest species will dictate prevention/control strategies directed toward remov al of oviposition sites through public

education.

2. Mapping – Utilize township/city/county maps to continually monitor major sources of larval/adult mosquitoes in addition to areas where control measu res have been instituted.

3. Set Action Thresholds – Decisions to apply public health pesticides shou ld be based on the analysis of either larval or adult mosquito surveillance data. Programs must establish a mechanism on which

decisions to institute control measures are based.

a. Determine which methodology shall be used to determ ine if and when control measures are

instituted.

i. For larval mosquito control this methodology can co nsist of numbers of larvae observed in larval dip counts or observation of larval prese nce in water sources.

ii. For adult mosquito control this methodology can con sist of:

1. Number and pattern of citizen’s service requests.2. Visual – numbers of mosquitoes landing on inspector /applicator within 1-minute periods. When practicable, landing rate counts shou ld be taken near or at times of peak mosquito activity for the species of concern. Performance of landing rate counts is only advised in areas or at times without significant mosquito-borne disease activity.

b. Determine threshold values that trigger control mea sures.

4. Physical Control or Source Reduction –Source reduction (the elimination, removal or red uction of larval mosquito habitats) typically is the most eff ective and economical long-term method of mosquito control, but this may not be practicable for many l arval habitats. Source reduction can be as simple as overturning a discarded bucket or disposing of a wa ste tire. These efforts often minimize and/or eliminate the need for mosquito larviciding in the affected habitat in addition to greatly reducing th e need for adulticiding in nearby areas.

a. Determine feasibility of removing or modifying ovip osition sites.

b. Maintain liaison with city/county agencies responsi ble for ditch/impoundment maintenance.

c. Maintain familiarization with jurisdiction health n uisance abatement policy.

5. Biological Control – These control methodologies are often resource-i ntensive and not usually practicable for many programs. Nonetheless, their f easibility should be explored.

a. Stocking of certain species of fish known to be pre dators of mosquito larvae, if allowed by applicable state or local authorities, may provide significant reductions in larval mosquito populations in basic programs where management of l arge perennial oviposition sites is to be the primary control strategy.

b. Utilization of bats, birds, dragonflies and other p utative predators of mosquitoes is both ecologically problematic and ineffective as a prima ry control strategy and is therefore not recommended as a major component of any control str ategy.

6. Chemical Control – Handling, disposal, personal protective measures and applications must be made in full accordance with product label specifications.

a. Larvicides – Often may be the primary control metho d in natural or man-made wetlands (salt marshes or tidal wetlands, riverine bottomlands, wo odland pools, freshwater marshes, meadow swales, roadside ditches, stormwater management pon ds, etc.). These can also be a primary control method in locations where mosquito populati ons are determined to be arising from defined, concentrated sources in urban areas or in close proximity to houses. Due to continual influx of adult mosquitoes from outlying areas, lar viciding programs may have limited visible effect on mosquito populations in jurisdictions lac king resources to adequately larvicide outlying production areas.

i. Several materials in various formulations registere d by EPA are labeled for mosquito larviciding. Choice of active ingredient and formul ation chosen will depend on sitespecific factors and resistance management, and may include:

1. Organophosphate - temephos

2. Microbial larvicides – Bacillus thuringiensis israe lensis (Bti) and Bacillus sphaericus (Bs)3. Growth regulators – methoprene

4. Monomolecular surface films

5. Oils – petroleum or mineral-based

6. Chitin synthesis inhibitors – diflubenzuron

ii. Larvicides, if used, should be specific for mosquit oes, minimize impacts to non-target organisms and must, in many instances, be capable o f penetrating dense vegetative canopies. Larvicide formulations (e.g., liquid, gra nular, solid) must be appropriate to the habitat being treated, accurately applied and based on surveillance data.

iii. Larvicide application equipment should be calibrate d and maintained per equipment manufacturer’s specifications and timetable, or per instructions from product registrant.

b. Adulticides – Adulticiding based on surveillance da ta is an extremely important part of any IMM program, and often forms the primary treatment meth od for basic programs. In fact, the general public typically associates basic mosquito control programs with spray trucks or “foggers,” not realizing the existence or importance of the other parts of the integrated program. Adulticides are applied so as to impinge upon the mosquito target i n flight or at rest on vegetation.

Adulticides utilized in basic programs are typicall y applied as an Ultra-Low-Volume (ULV) spray where small amounts of insecticide are dispersed by aircraft or truck-mounted equipment. A vast majority of mosquito control programs don’t have ae rial application capabilities, but most have some type of ground delivery system for adulticidin g. In some jurisdictions, adulticides may also be applied via “thermal fogs”, utilizing heat to at omize droplets. Adult mosquitoes may also be targeted by “barrier treatments”, which involve app lication of a residual insecticide to vegetation where mosquitoes are known to rest.

i. Adulticides should only be applied when established spray thresholds have been

exceeded.

ii. Non-residual adulticides applied to the air column in order to impinge upon mosquitoes in flight should only be applied when the target sp ecies is active.

iii. Adulticides should be applied strictly according to label specifications. This will produce minimal effects on non-target organisms and promote efficacy. Adulticides should not be applied in rainy or windy conditions.

iv. Adulticides should only be applied by personnel tra ined or state certified in their usage and handling, or when operating under the supervisi on of an individual having state

certification.

v. Adulticides labeled for mosquito control in part ma y include:

1. Organophosphates – malathion and naled

2. Natural pyrethrins

3. Pyrethroids – permethrin, resmethrin and sumithrin

4. Pyrethroid derivatives – etofenproxvi. Adulticides should be applied at label rates that a re efficacious as determined by monitoring. Applying doses lower than those that pr ovide adequate control can in fact

result in the need for additional adulticide treatm ents and can also encourage insecticide resistance by treating with sub-lethal doses.

c. Adulticide application equipment should be calibrat ed and maintained per equipment manufacturer’s specifications and timetable, or per instructions from the product registrant.

7. Monitoring for Efficacy/Resistance – Resistance management techniques attempt to mini mize the risk of mosquitoes becoming resistant to the existing ch emicals and should be practiced in even basic

programs.

a. Basic resistance management techniques can include:

i. Do not use the same class of chemical against both immature and adult mosquitoes.

ii. Apply pesticide at rate recommended on the label. D o not underdose.

iii. When possible, utilize a different chemical class a t the beginning and end of treatment

season.

iv. If possible, assess susceptibility at the beginning and sometime during the mosquito

season.

b. Resistance management can also involve utilizing su rveillance methods following larvicide or adulticide applications to continually check for co ntrol efficacy.

8. Public Education & Community Outreach – Education of the general public should be encour aged to teach residents how they can aid mosquito control b y disposing of (or modifying) containers.

a. The public should be notified via appropriate means of upcoming spray operations as soon as the

need is determined.

b. Beekeepers or persons not wishing their premises to be treated should be notified of any adulticiding operations per label specifications pr ior to application operations.

9. Record-keeping – Operators/applicators should record the followin g for each application and maintain the records for the time specified by the lead regu latory agency:

a. Applicator’s name, address and pesticide applicator certification number (if applicable)

b. Application date and time of day

c. Product name and EPA registration number

d. General location of application and approximate siz e of area treated

e. Amount of material applied

f. Application rate