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Pests and pest control in Washington

Pests to know in Washington

Why each one matters here is cited in the sections below.

Pests documented in Washington

From public GBIF occurrence records since 1990. A record means a species was documented in Washington, not that it's common near you.

Many public records (502)

Fewer public records (151)

Range named by extension sources (6)

Termites in Washington

Washington has two native termites: the dampwood termite and the subterranean termite.[2]

Invasive species reported here

The Washington State Department of Agriculture runs an ongoing Japanese beetle eradication project with a quarantine area.[3]

Pests local experts flag

  • The hobo spider is one of the most commonly found funnel-web spiders in parts of Washington, and recent research has not shown it to be harmful to people.[4]
  • Tick-borne diseases acquired in Washington include anaplasmosis, babesiosis, Lyme disease, Rocky Mountain spotted fever, tick-borne relapsing fever, tick paralysis, and tularemia.[6]

Public agencies that handle pests

Each mosquito season, the Washington State Department of Health traps and tests mosquitoes for West Nile virus and supports testing by local health jurisdictions and mosquito control districts.[7]

Hiring a licensed company

Washington's pesticide regulatory agency is the Washington State Department of Agriculture (Pesticides and Fertilizers).[1]

Licensing agency: Washington State Department of Agriculture — Pesticides and Fertilizers[1].

See also how to check a pest control license.

Free local help

WSU's Pestsense site provides fact sheets on managing common indoor pests using integrated pest management.[8]

Local guides in Washington

Through the year

Summer to Fall
Dampwood termites in Washington swarm in late summer or fall, especially after rain.[2]
Summer to Fall
Yellowjackets are especially aggressive in late summer and fall and sometimes sting without being provoked.[5]
Spring to Fall
West Nile virus detections in Washington have occurred as early as May and as late as October.[7]

Sources

  1. National Pesticide Information Center, “State Pesticide Regulatory Agencies.” npic.orst.edu/reg/state_agencies.html (accessed 2026-10-06)
  2. Washington State University (Pestsense), “Termites.” pestsense.cahnrs.wsu.edu/fact-sheet/termites/ (accessed 2026-10-06)
  3. Washington State Department of Agriculture, “Japanese Beetle.” agr.wa.gov/departments/insects-pests-and-weeds/insects/japanese-beetle (accessed 2026-10-06)
  4. Washington State University (Pestsense), “Hobo spider.” pestsense.cahnrs.wsu.edu/fact-sheet/hobo-spider/ (accessed 2026-10-06)
  5. Washington State University (Pestsense), “Yellowjackets.” pestsense.cahnrs.wsu.edu/fact-sheet/yellowjackets/ (accessed 2026-10-06)
  6. Washington State Department of Health, “Ticks.” doh.wa.gov/community-and-environment/pests/ticks (accessed 2026-10-06)
  7. Washington State Department of Health, “West Nile Virus.” doh.wa.gov/you-and-your-family/illness-and-disease-z/west-nile-virus (accessed 2026-10-06)
  8. Washington State University, “Pestsense.” pestsense.cahnrs.wsu.edu/ (accessed 2026-10-06)

Updated 2026-10-06. Every statement on this page comes from the cited state, federal or university source. Spot an error? Tell us.