Types of Vector Control

The purpose of the Williams County Vector Control District (WVCD) is to manage mosquito populations in and around the major population centers of Williams County, excluding Tioga as they have their own Vector Control District. WVCD conducts both aerial and truck mounted spraying operations during the summer months.

Williams County Vector Control routinely operates truck mounted sprayers which can apply ground based larvicide and adulticide treatments. Aerial treatments are conducted by contracted certified aerial applicators. Annual aerial larvicide and adulticide missions are also conducted in collaboration with the U.S. Air Force Reserve based out of Youngstown, Ohio.

Multiple factors are taken into consideration when deciding if, and when a treatment will occur. Williams County Vector Control staff routinely collect mosquito samples five days a week from traps located throughout Williams county. An increasing mosquito population coupled with favorable weather conditions inform the decision of whether or not a treatment is necessary.

The District is divided into spray blocks, which can be visualized in the map below.

Larvicides refer to pesticide products used to prevent the larval mosquito population from growing into biting adults. Williams County Vector Control uses a variety of ecologically-friendly larvicides like B.t.i (Bacillus thuringiensis israelensis).

Larvicide treatments are conducted using helicopters, fixed wing aircraft, and Unmanned Aerial Systems (UAS), or more commonly referred to drones. The helicopters and fixed wing aircraft treat large areas of mosquito larvae. UAS use granular product to treat mosquito breeding sites that are inaccessible from the ground and too small for full-size manned aircraft. UAS can be used to treat an area of anywhere from an acre or less up to about 100 acres.

Adulticides refer to pesticide products used to manage adult mosquito outbreaks. Williams County Vector Control only uses mosquito control products that are registered with the EPA and approved for use over residential and agricultural areas. Vector Control typically uses the product Zenivex (active ingredient: etofenprox), but may use the product Imperium (active ingredient: Deltamethrin) at times. Collaborative missions with the U.S. Air Force Reserve occasionally use Trumpet EC with Naled.

The EPA’s evaluation process for mosquito control products includes assuring that when such products are used according to the product label directions, they do not pose risks to vulnerable populations, including children and pregnant women and that they do not pose risks of concern to the general population or to the environment. Information about the EPA process can be found on their mosquito control website.