Local guide · WA

Pests and pest control in Kennewick, WA

Pests to know in Kennewick

Mosquito · Subterranean termites · Non-Biting Midges · Japanese Beetle

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

Termites in Kennewick

WSU says dampwood termites in the area swarm in late summer or fall, especially after rain, while subterranean termites may swarm any time of year.[3]

Invasive species reported here

WSDA urges people working in Yakima, Benton or Franklin counties, including farmers, nurseries and landscapers, to help prevent the spread of invasive Japanese beetle.[8]

Pests local experts flag

  • Benton County is listed with 22 mosquito species, and the Benton County Mosquito Control District has physically trapped 16 of them.[5]
  • The district says large numbers of midges, often mistaken for mosquitoes, hatch locally as soon as winter turns to spring.[7]

Climate

Central Kennewick (ZIP 99336) is in USDA plant hardiness zone 7b, where the average coldest winter night is 5 to 10°F.[12]

Public agencies that handle pests

  • When Benton County Mosquito Control finds a positive mosquito sample, it notifies Benton-Franklin Health, which shares the information with the public and health providers.[1]
  • Benton County Mosquito Control District serves Kennewick, including Finley, as one of seven municipalities in its boundaries.[4]
  • The Benton County Mosquito Control District tests mosquitoes for West Nile virus, St. Louis encephalitis virus and western equine encephalitis virus.[6]

Local rules and responsibilities

County laws in Benton, Franklin, Yakima and Walla Walla counties require backyard fruit tree owners to control pests that could infest nearby commercial orchards.[9]

Hiring a licensed company

In Washington, a WSDA Structural Pest Inspector license is required to inspect for wood-destroying organisms, their damage, or conditions that encourage them.[11]

Licensing agency: Washington State Department of Agriculture — Pesticides and Fertilizers[13].

See also how to check a pest control license.

Free local help

Benton-Franklin Master Gardeners hold an in-person plant clinic May through October; from November to April, questions go through the Kennewick office.[10]

Through the year

Summer to Fall
Benton-Franklin Health says West Nile virus cases occur during mosquito season, which begins in summer and runs through fall.[2]

Sources

  1. Benton-Franklin Health District, “Mosquito-Borne Diseases.” www.bfhd.wa.gov/programs_services/animals___insects/mosquitoes (accessed 2026-10-06)
  2. Benton-Franklin Health District, “West Nile Virus.” www.bfhd.wa.gov/health_topics/diseasesandconditions/west_nile_virus (accessed 2026-10-06)
  3. Washington State University Extension (PestSense), “Termites.” pestsense.cahnrs.wsu.edu/fact-sheet/termites/ (accessed 2026-10-06)
  4. Benton County Mosquito Control District, “FAQs.” bcmcd.specialdistrict.org/faqs (accessed 2026-10-06)
  5. Benton County Mosquito Control District, “History.” bcmcd.specialdistrict.org/history (accessed 2026-10-06)
  6. Benton County Mosquito Control District, “Disease Monitoring.” bcmcd.specialdistrict.org/disease-monitoring (accessed 2026-10-06)
  7. Benton County Mosquito Control District, “Mistaken Identity: Are They Midges or Mosquitoes?.” bcmcd.specialdistrict.org/mistaken-identity-are-they-midges-or-mosquitoes (accessed 2026-10-06)
  8. Washington State Department of Agriculture, “Japanese Beetle Quarantine.” agr.wa.gov/departments/insects-pests-and-weeds/insects/japanese-beetle/quarantine (accessed 2026-10-06)
  9. WSU Extension Benton & Franklin Counties, “Benton & Franklin County Horticultural Pest & Disease Boards.” extension.wsu.edu/benton-franklin/agriculture/pests/bentonfranklincohortpestdiseaseboards/ (accessed 2026-10-06)
  10. WSU Extension Benton & Franklin Counties, “Ask a Master Gardener.” extension.wsu.edu/benton-franklin/mastergardeners/ask-a-master-gardener/ (accessed 2026-10-06)
  11. Washington State Department of Agriculture, “Commercial Applicators.” agr.wa.gov/services/licenses-permits-and-certificates/pesticide-license-and-recertification/pesticide-and-spi-licensing/commercial-applicators/commercial-applicators (accessed 2026-10-06)
  12. USDA ARS and PRISM, via phzmapi.org, “Plant hardiness zone for ZIP 99336 (2023 USDA map data).” phzmapi.org/99336.json (accessed 2026-10-06)
  13. National Pesticide Information Center, “State Pesticide Regulatory Agencies.” npic.orst.edu/reg/state_agencies.html (accessed 2026-10-06)

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