What Triggers Mosquito Spray?
The Prince William County Mosquito Control Branch typically sprays for adult mosquitoes Monday through Friday throughout the mosquito season, and spray is often done at night. There is no set schedule or order in which the blocks are sprayed. Rather, there are criteria established by the branch that would trigger mosquito spray in a given area or neighborhood. One trigger that could result in mosquito spray is based on surveillance trapping of adult mosquitoes. If a threshold number of female mosquitoes is met or exceeded on a given night, this can trigger mosquito spray for that trap area. Another trigger for mosquito spray is that the mosquitoes caught in a trap area test positive for West Nile Virus. Click here for information on the first West Nile positive mosquitoes of the 2010 season.
