City Health Department staff gave the City Council an update Monday regarding the City’s Mosquito Control program. The Department continues to follow an integrated, multifaceted approach to controlling mosquito-borne disease, including:

  • Source Reduction (eliminating mosquito breeding areas such as treating or draining stagnant residential swimming pools)
  • Surveillance (setting out mosquito traps in 12 primary locations across the city and conducting sampling/testing for six months, beginning in April each year)
  • Larviciding (reducing mosquito larvae populations by introducing “dunks,” predatory fish and other larvicide to natural and man-made areas of water)
  • Adulticiding (reducing adult mosquito populations through low-volume ground-level spraying around positive trap locations)
  • Public Education (outreach including direct mail, utility bill inserts and neighborhood signs)

In 2020, the Health Department set out 324 traps, tested 5,204 mosquitoes and found 13 positive West Nile test results among the mosquito samples. Only one human case of West Nile virus was reported in Richardson last year. 

For an updated, interactive map of Richardson neighborhoods with information on mosquito test results and any action being taken in each area, click here. For e-mail notifications of spraying events, sign up at