Mosquito Control District
|5/23/19: Recent sampling of floodwater areas and wetlands have revealed significant numbers of mosquito larvae. As a result, the Mosquito Control District will be using a helicopter to treat 20 to 30 locations between Ridgefield and the area south of Vancouver Lake over the next several days. Aerial treatment is not occurring in residential areas.|
Public Health and the Mosquito Control District work together to control mosquitos in Clark County. District activities are guided by the work plan adopted by the Mosquito Control Board of Trustees to address mosquito nuisance abatement and threats of West Nile Virus.
Abatement and operations
The Clark County mosquito crew conducts surveillance and abatement activities through the active mosquito season, usually April 1 through October 1, each year. The priority is to attack mosquitoes at their source, by treating mosquito larvae as they hatch. It is far more effective to reduce mosquito populations at their source, before they fly into neighborhoods, than to fog large, open areas in attempt to eliminate adult mosquitoes. It is very difficult to reduce mosquito populations once they have spread from the breeding source.
Control measures used by the crew comply with policies adopted by the Board of Trustees of the Mosquito Control District and with state and Environmental Protection Agency regulations. Biological control methods are used that have the least adverse effect on humans, pets, wildlife, and the environment.
The crew implements an Integrated Pest Management (IPM) program and uses a variety of equipment to control mosquitoes. Treatment methods in Clark County include larvicide applied by helicopters, broadcast from trucks, all-terrain vehicles, amphibious vehicles, and on foot from backpack applicators. Larvicide briquettes are placed into storm drains and catch basins. Limited treatment is applied to adult mosquitoes due to the limited effectiveness of this method and the short duration of the materials. Due to legal restrictions, the Mosquito Control District cannot spray or fog neighborhoods or private residences.
The Clark County mosquito control crew works April 1 through October 1 each year. During that time requests for service or information regarding mosquito control can be made through either the 24-hour service request line at 360.397.8430 or on-line service request.
When reporting an area of standing water, please provide the following information:
- Your first and last name (please speak clearly and slowly, and spell your last name).
- Your address, including city and zip code.
- Your telephone number.
- Description and location of the problem.
A mosquito crew will visit the problem area and determine treatment or monitoring needs. You will receive a phone call only if additional information is needed to find the problem site
- Mosquito Larvicide Bti
- Mosquito Larvicide Treatments Fact Sheet
- Don't give mosquitoes a place to breed
- West Nile Virus Alert Level for Clark County
- West Nile Virus information for Washington State
- Zika Virus (Note: There is currently no threat of Zika Virus in Clark County)