City of Davis 

Integrated Pest Management Program 

2008 Annual Report 

Submitted to the Natural Resource Commission on March 23, 2009 

Prepared by: Martin Guerena, IPM Specialist and 

John McNerney, Wildlife Resource Specialist. 

2008 Integrated Pest Management Report 1
1.0 Overview 

The purpose of this report is to provide the Natural Resource Commission (NRC) with an 

overview of City efforts to control pests in a variety of settings in and around the community. 

As outlined in the report, staff employs a number of methods to achieve the functional, public 

safety, and aesthetic vegetation control standards that have been established for City managed 

areas. The report also reviews the policy decisions that shaped the City’s current approach to 

weed management and provides analysis of several factors that influence program decisions. 

2.0 Introduction and Background 

In the 1980’s the City of Davis’ pesticide use was similar to other cities and agricultural 

operations. Much of the maintenance of park, greenbelts, landscaping, bike paths, streetscapes 

and open space consisted of scheduled applications of fertilizers and pesticides. The pesticides 

used were a mixture of Category I (Danger), II (Warning) and III (Caution) compounds. 

In 1989 the city established an Integrated Pest Management (IPM) program where new methods 

of managing public landscapes were imposed, these included: 

• First IPM Policy developed by the Parks and Community Services department. 

• First IPM specialist hired by the City of Davis. 

• Issuing written pesticide recommendations. 

• Consolidate and centralize pesticide storage in upgraded facilities. 

• Cooperating with UCD in experimenting and utilizing beneficial insects and other 

practices. 

• Minimize toxic pesticide use. 

• Increased staff training and education on IPM. 

Seven years later in 1996, the city council approved the creation of an IPM task force which was made 

up of UCD experts including IPM specialist, entomologist, weed scientist and plant pathologist as well 

as representatives of the US Forest Service and private landscapers. The task force primary goals were 

to: 

• Reduce the pollution load of pesticides within the City of Davis 

• Increase awareness and use of IPM by citizens via education & outreach 

• Provide recommendations that will assist in improving the IPM program 

• Reduce the use of pesticides within the city, by businesses and retail operations via technical 

assistance and education programs 

The IPM task force report was completed in 1998 with the following conclusions: 

• Identify the conditions causing pest problems. 

• Devise ways to change conditions so as to discourage reoccurrence of pests. 

• Select least hazardous combination of strategies to control the pests. 

• Conduct on going training and IPM advisory assistance. 

2008 Integrated Pest Management Report 2
In 1998 the Environmental Protection Agency (EPA) awarded the City of Davis a PESP (Pesticide 

Environmental Stewardship Program) Grant Award for IPM Education. The IPM demonstration signs 

and “garden friendly” posting throughout the parks and greenbelts are remnants of that funding. 

The IPM program came under review in 2000 by the Natural Resources Commission with the following 

recommendations: 

• Continue reducing category II applications. 

• Continue posting for pesticide applications. 

• Continue the native grasses area conservation. 

• Study the IPM coordinator option. 

• Continue training efforts with citizens and staff. 

2000 – 2007 Environmental resource supervisors (Open Space), wildlife resource specialist and the 

environmental compliance coordinator oversaw and reported on the IPM program. 

2001 Local interest group requested the County Agricultural Commissioner to investigate herbicide 

use and reporting within the city. The investigation revealed only minor deficiencies with 

recordkeeping due to the size of the three departments. Each department would maintain records and 

coordinate IPM activities. 

2005 Public Works develops an IPM plan, which includes: 

• Less reliance on chemical controls. 

• Maintenance of positive relations between the city’s departments, regulatory agencies, and 

concerned public entities. 

• Balancing weed controls within departmental economic constraints. 

2007 Citywide pesticide use policy developed and IPM specialist hired. 

2008 IPM Policy developed. 

The citywide IPM Specialist position was staffed in the fall of 2007. The IPM Specialist 

coordinates citywide IPM activities, evaluates and trains field staff on alternative pest control 

methods, and keeps records for all departments. The position is currently funded between Parks 

& General Services (PGS) and Public Works (PW) departments. 

Parks maintenance personnel in the PGS department as well as contractors are involved in pest 

control activities, mostly weed control throughout the parks, greenbelts, open space, and 

landscaped street medians. Public Works has three divisions involved in pest control activities. 

The Wastewater Treatment Plant (WWTP) personnel maintain the grounds around the plant, 

lagoons, overland flow, associated open space and treatment wetlands. Challenges posed here 

are maintaining the function of the overland flow process by controlling broadleaf weeds like 

curly dock, mustards and perennial pepperweed. The wetlands are constantly threatened by the 

spread of invasive weeds such as star thistle (Centaurea solstitialis ) and perennial pepperweed 

(Lepidium latifolium). The transportation division maintains streets, roadsides, bike paths, and 

the old landfill/ pistol range site. Most weed control is done by a contractor who treats problem 

roadsides and non-landscaped traffic medians with herbicides in the late fall. The Collections 

division is in charge of maintaining stormwater flow within drainage channels, right of way 

2008 Integrated Pest Management Report 3
access and is responsible for maintaining the sanitary sewer system. Current pest control 

response is dictated by the results of pest population monitoring by field staff. Monitoring 

results are compared to action thresholds. Action thresholds include functional impairment, fire 

hazard, and aesthetic degradation. Functional impairments are infestations that impair the 

operation of a City facility, program, and/ or objective. Stormwater conveyance, for example, 

may be inhibited due to dense growth of invasive plants. In some instances aggressive pest 

species such as yellow starthistle (Centaurea solstitialis), and perennial pepperweed (Lepidium 

latifolium) are treated prior to threshold realization to prevent rapid colonization and habitat 

damage. Dense weed growth on City property, adjacent to private or public structures, creates a 

fire hazard. Weed infestations that occur in parks, bike or sidewalk paths, and road medians are 

considered hazardous and/ or of poor aesthetic value. 

The following section presents the 2008 calendar year activities with regards to the City’s IPM 

Program. IPM policies apply to all City departments. However, this report details P&CS and PW 

activities, as they have primary pest management responsibility. 

3.0 Program Achievements in 2008 

3.1 IPM Innovator Award 

This award from the California Department of Pesticide Regulation (DPR) is given to 

organizations recognizing their efforts to reduce chemical pesticides via cultural, biological and 

mechanical control methods. Throughout the years DPR has given out more than 100 IPM 

Innovator awards to honor California organizations that emphasize pest prevention, favor leasthazardous pest management, and share their successful strategies with others. The awards are 

part of a comprehensive, reduced-risk pest management strategy aimed at homes, schools, farms, 

and the environment. 

3.2 Our Water Our World (OWOW) Program 

The OWOW program continued to be implemented at three pesticide retail stores in Davis 

(Davis Ace, Redwood Barn and Nursery, and Longs Drugs) in 2008. This program provides 

“Less Toxic” fact sheets and shelf tags set adjacent to pesticides. In addition to the written 

materials, store employees are given training regarding what products are environmentally 

conscience alternatives for pest control. 

3.3 IPM Comic “The Exterminator” 

The IPM and Stormwater Pollution Prevention Programs partnered to create a comic book for 

youth and young at heart that demonstrates least toxic approaches to managing urban household 

pests. 

2008 Integrated Pest Management Report 4
3.4 Alternative Pest Control Practices 

Staff continued to work with alternative pest control methods including: 

 

• “Green pesticides”: products derived from soap, acetic acid, herbal oils or 

microorganisms. 

• Biological control: use of predatory organisms such as nematodes for grub controls on 

ball field turf, and promoting birds-of-prey to eat pest rodents. 

• Mechanical control: removal of weeds by “weed wackers”, tractor implements or hoes. 

• Grazing: use of goats and sheep at Mace Ranch wildlife habitat. 

• Mulching: use of wood chips to cover open ground, smothering weeds. 

• Sheet Mulching: mulching but with cardboard or weed cloth barriers. 

• Flaming: use of propane flamers to burn down broadleaf weeds. 

• Solarization: use of clear plastic during the summer to pasteurize the soil, killing or 

debilitating most weed seeds. 

• Flooding: use of flooding in the wetlands to deprive weeds of air. 

3.5 City of Davis IPM policy incorporating Pesticide Hazard Avoidance and Exposure 

Reduction (PHAER) zones. 

The city IPM Specialist revised the citywide IPM policy with the incorporation of the Pesticide 

Hazard and Exposure Reduction (PHAER) zones program. This strategy gives structure to the 

implementation process of the IPM policy in parks and greenbelts by allowing supervisors the 

needed flexibility in their management options and informing the citizens about the general level 

of pesticide hazard present on a site-by-site basis. These zones are designated as Green, Yellow 

and Special Circumstance Zones, with Green Zones providing the lowest potential for pesticide 

hazard and exposure. Each Zone has a corresponding pesticide list determined by existing 

toxicological data. Mace Ranch and Central Park are the first parks in the city to have the 

PHAER zone program implemented. Contracted landscape maintenance and pest control 

companies have been presented with this program and are expected to abide by it. Staff training 

of contracted company employees regarding this policy and project has been conducted in 

Spanish. 

3.6 City partnership with the UC Davis Arboretum and volunteers on the Central Park 

demonstration garden project. 

In 2007, city staff from both PW and P&GS participated in the design and development of the 

Central Park demonstration garden project. This project demonstrates the use of drought tolerant 

and native plants, zone irrigation, and alternative pest control. The city continues to collaborate 

with the arboretum with public outreach events related to the garden. 

2008 Integrated Pest Management Report 5
3.7 PW and PGS field staff received Pesticide Applicator Certificates 

Developed and conducted preparatory courses for City of Davis staff seeking Qualified 

Applicators Certificates. Lead a class once a week for a month before the scheduled exams 

covering materials such as pesticide safety, laws and regulations, and IPM practices. 

3.8 City of Davis IPM Web Site 

Online information on the City’s IPM program including access to the city’s IPM and pesticide 

use policies, details on how to deal with local pests, links to other useful sites as well as details 

on the Pesticide Hazard and Exposure Reduction (PHAER) zones program. The Exterminator 

comic is also available to download. 

4.0 Alternative Pest Control Activities

Several alternative pest control methods were continued in 2008 to reduce reliance on pesticides 

and meet IPM objectives. 

4.1 Weed management

Mechanical Removal: Mowing, weed trimming, and tilling continued to be utilized by City 

crews to control weeds and stimulate native grass growth. Extensive mowing and tilling were 

used in 2008 at the WWTP, Davis Wastewater Treatment Wetlands (Wetlands), park and 

greenbelt facilities and various open space areas. Some of these efforts resulted in higher costs 

associated with labor and equipment maintenance, but helped to reduce herbicide use. Feasibility 

of future reliance on these methods may be reduced due to budgetary constraints. 

Hand Removal: Seasonal employees and volunteers were utilized at the WWTP, Wetlands, and 

community garden sites to pull weeds from around landscaping and native plant restoration 

areas. Similar to mechanical removal this control method increases labor. Cuts in City labor 

force could reduce feasibility of this method; however, volunteer service may help to reduce 

costs. 

Flooding: Water level management continued to be effective at controlling weeds and Canada 

goose nest density at the local stormwater detention basins and the Wetlands. Water levels were 

raised onto the seasonal benches during winter months and allowed to remain into spring. 

Rx Burning: Prescribed fire was used at the Wetlands to stimulate native grasses and reduce 

weed seed production. 

Grazing: Livestock grazing is utilized at the Mace Ranch Community Park habitat area and Yolo 

County Grasslands burrowing owl preserve to meet burrowing owl habitat objectives. Livestock 

are free ranged for 2 months to meet this goal. 

2008 Integrated Pest Management Report 6
Use of Native Vegetation in New Landscaping Projects: The City continued to utilize native 

trees, shrubs, and grasses in municipal landscape projects. Native plants were included in the 

landscaping of the new Central Park Garden. Native grasses were seeded along several pond 

benches at the Wetlands. Once established native vegetation can successfully out compete weed 

species. This helps to reduce weed management activity. Native plants also require less 

irrigation, which reduces risk of offsite movement of fertilizers or pesticides into the stormwater 

system. The use of native plantings increases the costs of the project. Reliance on the use of 

native plants may be reduced due to budgetary constraints. 

Weed Habitat Removal: P&GS landscape contractors and park field staff continued to maintain 

mulch around landscaped areas. Mulch helps to smother weeds and reduces the need for 

fertilization and water. 

Proper Timing of IPM Control Activities: Continued monitoring of weed development led to 

proper timing of weed management. Growth stage of weeds often dictates type of management 

method to be used. 

Organic Herbicide: Trials with these products continue be tested and are showing promising 

results. Concentrated acetic acid (vinegar) in combination with a soap based herbicide or with 

the herbal oil based herbicides have shown promise in burning down annual broadleaves. This is 

encouraging for areas that are sensitive to conventional pesticide use due to human and pet 

exposure or wildlife habitat. Work will continue in other areas as well, especially those that 

relate to water quality issues. 

Weed Flaming: Propane flamers are utilized when conditions of high humidity reduce the 

options for other forms of weed control. This technique is effective on small, recently 

germinated broadleaf weeds. 

4.2 Other Pest management

City Stormwater Basins and Wetlands Pest Control: Mosquito control within the local 

stormwater retention basins and at the Wetlands continued to be through water level 

manipulation and biological control only. Bringing water levels down during the peak mosquito 

production time allows predatory species to access larvae. All areas continued to support 

sufficient populations of predatory mosquito fish (Gambusia affins). 

Rodents were controlled in a couple of parks by placing secure baiting stations in strategic areas. 

Results were achieved in a couple of weeks. Musk rats and ground squirrels within stormwater 

basins, WWTP, Wetlands and parks were removed as needed via both non-lethal/non-toxic live 

trapping and least toxic baiting. The city has also implemented a barn owl nest box installation 

program in parks and neighborhoods. The program aims to increase the population of natural 

predators to help regulate rodent pest species within the city planning area. 

Hackberry tree aphid control on some parks and parking lots are preformed using imidacloprid to 

control the aphid and thus the production of honeydew. This product is also occasionally used to 

2008 Integrated Pest Management Report 7
control beetle grubs on the fields at Playfields Park. Predatory nematodes are used as a 

preventative on these grubs but if population thresholds are exceeded the insecticide is used. 

Sewer line root control is conducted by the Collections division of PW as part of a 

comprehensive sanitary sewer maintenance program. This regulatory mandated program aims to 

prevent sanitary system overflows or system failure by controlling, among other things, root 

intrusion. Root control includes, but is not limited to, the use of Vaporooter, a class one category 

pesticide. Prior to 2008, this product was not included in pesticide use reporting due to a 

misunderstanding of product registration. Since becoming aware of this error, changes have been 

made to include the product in pesticide reporting and ensure that it is used in accordance to the 

City’s pesticide application policy. Mechanical methods as well as alternative herbicides will be 

evaluated to determine the most efficient and safe way to control root intrusion in the sewer 

lines. 

 

5.0 Public Outreach and Education 

The City continued to provide public outreach and education on pesticides using several forms of 

communication. City staff was also educated on weed and pest control techniques and current 

trends in IPM. Outreach and education efforts included: 

• Development of City of Davis’ IPM website. 

• Development of IPM comic “The Exterminator”. 

• Notification of City herbicide application activities in parks and greenbelts via the 

Pesticide Hotline. 

• Tips and alternatives to pesticide use provided in the annual PW sponsored “Utility 

Connections” and citywide “Focus” newsletters. 

• Distribution of IPM educational literature at community events. The city partnered with 

the Master Gardener Program to provide free advice at the Celebrate Davis event. The 

Davis Green Home and Garden Expo provided opportunities to display the city’s effort at 

least toxic pest control. Tables featured the OWOW program, bat and owl boxes as well 

as pamphlets and handouts on our pest control programs among other things. 

• Periodic presentations at local schools regarding stormwater quality including tips and 

alternatives to pesticide use. 

• Presentations on least toxic pest control at the community gardens, Central park garden 

and the Mace Channel Herb Garden. 

• City sponsored annual Horticulture Pest Control Seminar where continuing education 

units are available to city staff and other pest control professionals from the school 

district and surrounding communities. 

• Pesticide safety training for City field staff. 

• Attendance at IPM conferences by departmental staff involved with IPM coordination. 

• Annual presentations to the city council and citizen advisory commissions. 

• Encouraging local pesticide venders to participate in the OWOW program. 

• Use of positive posting at location where alternatives to chemical pest control were in 

use. 

2008 Integrated Pest Management Report 8
6.0 2008 Pesticide Use 

TABLE 1: Summarizes pesticide use1 by product for calendar year 2008 with comparison to 

2005 through 2008. 

Product EPA Category 2005 Use 2006 Use 2007 Use 2008 Use 

Round-up [3] III 101 gal 100 gal 180 gal 127 gal 

Vaporooter [7] I No data No data No data 19.5 gal 

Surflan As III 0 gal 0 gal 0 gal 0 gal 

Prepair III 0 lbs 7.7 gal 0 gal 0 lbs 

Atrimec III 13.5 gal 0 gal 0 gal 0 gal 

Safer Soap III 0 gal 2.7 gal 6.1 gal 0 gal 

Garlon 4 III 3.7 gal 20.8 gal 22 gal 1.1 gal 

Goal [1] II 17.8 gal 100 gal 180 gal 21.2 gal 

Manage III 2.2 lbs 0.006 lbs 0.9 g 1.3 g 

Turflon III 1.1 gal 0.2 gal 0.03 gal 3.1 gal 

Transline III 0.26 gal 1 gal 0.3 gal 1.3 gal 

Telar III 10.8 oz 17 oz 36.1 oz 8.7 oz 

Fusilade III 0 gal 0.02 gal 0.06 gal 0.25 gal 

Aquamaster [8] III 13.3 gal 1.5 gal 3.9 gal 1.8 gal 

Merit III 8.4 gal 8.5 gal 0 gal 0 gal 

Direx 4L III 6.8 gal 2.5 gal 4.7 gal 0.5 gal 

Snapshot III 4825 lbs 2922 lbs 3325 lbs 5900 lbs 

Shark III 0 gal 0.03 gal 0 gal 0 gal 

Clarity [2] I 1 gal 2.6 gal 1.1 gal 0.7 gal 

Weedar 64 [2] I 5 gal 1.9 gal 3.4 gal 2.2 gal 

Barricade III 0 gal 0.2 gal 5.2 gal 2.3 gal 

Greenmatch [6] III 0 gal 0 gal 1.3 gal 0 gal 

Zenith 75WSP III 0 gal 0 gal 0.3 gal 0.4 gal 

Sedgehammer III 0 lbs 0 lbs 3.8 g 104.3 g 

Payload III 0 gal 0 gal 2.7 gal 2.5 gal 

Pendulum III 0 gal 0 gal 0 gal 500 lbs 

Scythe II 0 gal 0 gal 0 gal 1.3 gal 

Landmark III 0 gal 0 gal 2.3 gal 0.9 gal 

Milestone III 0 gal 0 gal 2.9 gal 0.5 gal 

Notes: 

[1] Used primarily in native grass restoration sites with limited public access (e.g. outlying open spaces and Davis 

Wetlands). Includes Goaltender. 

[2] Use of this material is restricted to the Overland Flow process of the Wastewater Treatment Plant. Public access 

is prohibited. 

[3] Combined Round-up products (Ultra, Pro, Weather max). 

[6] Organic herbicide 

[7] Used in sewer lines to remove intruding roots 

[8] Includes Rodeo, the old name for Aquamaster (aquatic glyphosate formulation)

 

1

 Includes City contracted pest control applications. 

2008 Integrated Pest Management Report 9
6.2 Comparison of 2008 Usage to 2007 Usage

Use of liquid products in 2008 was 45% lower than in 2007 (416 gallons vs. 187 gallons). Solid 

products were used more (56%) in 2008 than in 2007 (5900 pounds vs. 3325 pounds). The data 

suggests that in years where pre-emergence herbicides increases, post emergence use decreases. 

This year the use of pre emergence is lower in the first two months and is expected to reduce for 

the rest of the year. The use of post emergence herbicide is also expected to decrease somewhat 

because of the increased use of “green herbicides” as a substitute in some situations. 

6.3 Pesticide Use by Management Area

 The City currently manages 1736 acres of land that are subject to IPM. This acreage is divided 

into 6 major management areas including: Parks, greenbelts, and streetscapes (528 ac.); Open 

Space (548 ac.); Transportation System (30 ac.): Stormwater System (101 ac.); Wastewater 

System (489 ac.); and Facilities (40 ac.). The 6 major areas are further divided into sub areas. 

Table 3 details the sub areas and offers a percentage of total annual use by major area, 

Table 3: Percentage of total pesticide use by major area in 2008 with 2007 comparison. 

Major Area Sub Area Acres % of Total Use 2008/ 

2007 

Parks, greenbelts, and 

streetscapes 

528 46/ 60 

Open Space 548 2/ 2 

Agricultural buffers 

Restoration areas 

Mitigation habitat 

Transportation System 30 7/ 8 

Street median and Shoulders 

Sidewalks 

Bike paths 

Stormwater System 101 <1/ <1 

Detention/habitat ponds 

Drainage stations 

Conveyance channels 

Wastewater System 489 34/ 28 

Wastewater Plant 

Davis Wetlands 

Sewerline Root Control 10/NA 

Facilities 40 1/ 2 

Old landfill/ pistol range 

Corp yards, facility parking 

and landscaped areas 

1736 100 

2008 Integrated Pest Management Report 10
2008 Integrated Pest Management Report 11

7.0 Program Goals and Challenges for 2009 

7.1 IPM Goals for 2009 

PW and P&GS will continue to investigate and utilize feasible alternative pest control methods 

as directed by the IPM Specialist. PW will continue to implement its herbicide reduction plan to 

further refine pest control activities for less reliance on conventional pesticides. 

The following parks will be included in the PHAER zones program: 

• Winter of 2009: Central Park and Mace Ranch Park 

• Spring of 2009: Arroyo Park, Walnut Park and Community Park. 

• Summer 2009: Pioneer Park, Slide Hill Park, Chestnut Park, Sandy Motley Park. 

• Fall 2009: Westwood Park, Barovetto Park, North Star Park and Sycamore Park. 

The IPM Coordinator will continue to work on outreach such as an “Adopt-a-Park” program that 

recruits volunteers to participate in alternative weed control at select parks in Davis. 

Public outreach and education on IPM will continue through literature and staff presentations at 

various public events. 

Trainings will continue for P&GS and PW staff on pesticide safety and IPM practices. 

Crew supervisors from PW will continue to test alternatives to current sewer line root control 

methods. Tests on alternative herbicides and methods will continue in order to find a less toxic 

alternative. 

7.2 Anticipated Challenges for 2009 

 

Pest control strategies are dictated by weather, pest persistence and staff availability to 

implement management techniques. Persistence of infestations and budgetary constraints may 

hinder alternative control methods and cause an increased reliance on conventional methods 

primarily because the service level standards expected by the community. While the majority of 

staff has accepted and works with IPM practices, some concern over effectiveness of alternative 

methods continues. Primarily, the concern is that alternative methods are not cost effective and 

may not be suitable in certain applications. The IPM specialist will continue to work with staff 

and management to keep them informed on pesticide regulation updates, safety, and conduct 

field trial to demonstrate alternatives, their effectiveness, limitations and costs.