More Information About Mosquito Control

The following laws define the functions and responsibilities of the Mosquito Control District: Chapter 2-9 of the St. Lucie County Code of Ordinances and Compiled Laws (as extracted from Chapter 29502, Acts of 1953, Laws of Florida, amending Chapters 22460, Acts of 1943 and 13369, Acts of 1927), Chapter 388, Florida Statutes, and Rule 5E-13, Florida Administrative Code.

As set forth in Section 2-9-29 of the St. Lucie County Code of Ordinances and Compiled Laws, "...all depressions, marshes, ponds, lakes, lagoons, ditches and other places wherein mosquitoes and sandflies incubate or hatch are hereby declared to be public nuisances, as harmful or inimical to the comfort, health and welfare of the inhabitants and are to be abated as hereinafter provided." Pursuant to Section 2-9-20, the Mosquito Control District is directed to do any and all things necessary to control and eliminate mosquitoes and sandflies and is further authorized to erect and install pumps, dikes and other structures and equipment and apply such chemicals and other substances necessary to fulfill this duty. The abatement of nuisance arthropods (including mosquitoes and sandflies) has been declared to constitute a public purpose necessary for the maintenance of the health of the inhabitants of the District.

Personnel

The District employs 21 full-time and 19 part-time or temporary persons (26.3 full-time equivalent) in the following four divisions: administration, biology/inspection, adulticiding operations, and impoundment operations. The administrative division is staffed by the Director, one Executive Assistant, and one Senior Accounting Clerk. The biology/inspection division is staffed by the Inspection Manager, two Entomological Inspector III's, three Entomological Inspector II's, two Entomological Inspector I's, and one Executive Assistant. The biology/inspection division oversees the adulticiding operations division, which is staffed by one part-time Fog Truck Supervisor, 11 part-time Equipment Operators, and up to five temporary Equipment Operators. The impoundment operations division is staffed by two Impoundment Foremen, two Heavy Equipment Operator II's, two Heavy Equipment Operator I's, two Impoundment Operator II's, and two Impoundment Operator I's.

Facilities

District headquarters is at 3150 Will Fee Road, Fort Pierce, FL 34982, and shares the County compound with the Road and Bridge Division, the Parks and Recreation Division, and the Central Services Department. Facilities on-site include: administration building, biology/inspection division facility, equipment repair bays (currently jointly used by Central Services), chemical storage bay, chemical mixing/storage building, parts storage/maintenance building, exterior equipment storage areas,  covered vehicle storage bay (all on about 1 acre). Other items include: approximately 4000 acres of coastal mosquito impoundments, 41 miles of dikes and perimeter canals, 1040 feet of weirs, more than 240 lagoon-fringing culverts, 24 pump stations, 24 aerator stations, educational signs, boardwalks, 41 miles of walking and cycling trails, four covered picnic tables, eight fishing piers, eight crabbing docks, two birdwatching platforms, two observation towers, five canoe launches, and 12 parking lots for the impoundment parks.

Equipment

The District operates eight fog trucks, eight fog/inspection dual use vehicles, two administrative vehicles, four field pickups/service vehicles, a pump truck, a lift-truck, a front-end loader, a backhoe, a 1-ton dump truck, a 12-cubic-yard dump truck, 50 electric pumps, a portable larviciding tank, two mules (not the animal) and a variety of other small equipment.

Monitoring Programs

District employees monitor many environmental parameters (water quality, wind speed and direction, tide water levels, rainfall, relative humidity, etc.), in order to effectively manage the impoundments, as part of the overall District-wide control effort. Mosquito population samples are collected four times a week from 22 Mosquito Magnets (traps) and once a week from about 30 other Magnets.  Scheduling of control measures is based on those trap counts along with landing rate counts and requests for service from the public.

Seven sentinel chicken flocks are maintained, monitored, and tested for detection of Saint Louis Encephalitis and West Nile Virus (along with a dead wild bird reporting network).

Types of Control

The primary types of control for mosquitoes and sandflies are source reduction, larviciding, adulticiding, and biological methods.

Source reduction is the prevention of complete development of mosquitoes through physical manipulation or chemical control of breeding sites. Source reduction is the only effective way to control salt marsh sandflies.

Larviciding is the temporary control of mosquito larvae by liquid, powder, or granular insecticides or growth regulators.

Adulticiding is the temporary control of adult mosquitoes by ultra-low-volume (ULV) insecticide aerosol sprays.

Biological control is accomplished by stocking predators (e.g., mosquitofish) and other enemies (e.g., parasites) of mosquitoes.

These four control techniques complement each other, and are part of an integrated pest management (or IPM) strategy.

Adult Control Agents

Adulticiding and larviciding employ chemical and biological (e.g., natural bacteria) agents to achieve effective mosquito control. Available mosquito adulticides are limited in number and type. They belong to several general groups, including artificial and natural pyrethroids, organophosphates, and carbamates.

Artificial pyrethroids are used by the District for ground adulticiding, and include permethrin, etofenprox, sumithrin, and resmethrin, which can be synergized (for greater effectiveness) with natural piperonyl butoxide, and mixed with carrier mineral oils.

Aerial adulticiding is conducted during public health emergencies or as a preventive measure when mosquito-borne virus transmission is detected locally (e.g., in sentinel chickens).  The organophosphate compound naled is used. It is particularly effective against the mosquito species that carry Saint Louis Encephalitis and West Nile Virus.

Carbamates and other organophosphates are not currently used by the District.

Wetland Management

The District's Impoundment Program uses an ecosystem management approach for salt marsh mosquito control, following adaptive strategies based on biological and chemical research. The impoundments are open to natural tides most of the year but are kept flooded (partly closed, with constant water exchange) during the summer breeding season to minimize the amount of exposed mud available for mosquito egglaying, a procedure known as rotational impoundment management (RIM).

The District's land acquisition/mitigation/donation program is a critical component of its impoundment management effort.  This program has been successful in helping to acquire: Bear Point Sanctuary, Vitolo Family Park, Blind Creek Park (ocean to river), Ocean Bay, Queens Island, Kings Island, Indrio Blueway, Harbor Branch Preserve, and Wildcat Cove.

The Bear Point Impoundment is an approved mitigation bank for which mitigation credits have been sold since 2005, mainly to the Florida Department of Transportation for public road and bridge projects.

Public ownership of the impoundments and adjacent natural coastal communities is necessary to achieve maximum public benefits and ecological improvements. This leads to better mosquito control through non-chemical methods and enhanced public access and recreational opportunities along the Atlantic beachfront and Indian River Lagoon.

Acquisition and restoration has been accomplished through various Preservation 2000 and federal grant programs, including: Florida Communities Trust, Conservation and Recreation Lands, Save Our Rivers, Save Our Coast, and State of Florida Recreation and Parks (Additions & In-Holdings).  Special thanks go to the National Coastal Wetlands Restoration Act Grant Programs for their unwaivering support of coastal wetlands preservation and restoration in St. Lucie County.

Research

Partnership studies have been conducted with several public and private research organizations such as Harbor Branch Oceanographic Institution, South Florida Water Management District (Surface Water Improvement and Management Program), Smithsonian Institution, Swedish EPA, State of Florida Marine Research Institute, Indian River Lagoon National Estuary Program, Florida Medical Entomology Laboratory, Ocean Research and Conservation Association, and Florida Institute of Technology.

Studies have focused on improving water quality in the impoundments and estuary and also increasing the breadth of  faunal use of impoundments (wading birds, fish, etc.), as part of general efforts to increase biodiversity and productivity of the Indian River Lagoon ecosystem.

Education

Public awareness of these issues is enhanced through our "Mangroves, Mosquitoes and Man" elementary education program, 4-H site visits, H₂O Camps, Job Training Center ("Restore the Environment and Lagoon"), public lectures, and other educational walking and boating trips.

Achievements

Some of the District's many achievements include:

The Secretary's Environmental Award for Wetland Enhancement and Restoration from the Florida Department of Environmental Protection in 1990.

The Achievement Award for Mosquito Control from the National Association of Counties in 1991.

Jim David, Mosquito Control Director, was named the Saint Lucie County Environmentalist of the Year by the Conservation Alliance of Saint Lucie County in 1999, for administering the District Land Acquisition and Preservation Program (more than 55% of the coastal barrier islands in St. Lucie County now are under public ownership).

The Walter B. Jones Memorial Award for Excellence in Local Government (Coastal Zone Management) from the National Oceanic and Atmospheric Administration in 2001.

A Major Challenge

As the St. Lucie County human population grows, the District must continue to develop more effective and efficient techniques and to encourage better water management practices (such as surface water conservation areas, alternative water supplies, canal aquatic weed control, microjet grove irrigation), in order to continue to be effective in its control efforts. 

With the westward spread of urban development, humans will encounter larger mosquito populations, which are a direct result of limited surface water management in rural areas. Providing increased service in these fringing areas and effective response to any mosquito-transmitted viruses detected there creates future budgetary and management challenges.

For more information please contact us at:

(772) 462-1692
Byersb@stlucieco.gov