Ask The City: Mosquito Spraying

The Question:

On 7/21 at about 11:30 pm there was a truck that I believe was a city truck, it had the yellow work lights on it, driving up and down the streets spraying something. What were they spraying?

“City of Laramie Mosquito Control operations apply a permethrin based insecticide to control adult mosquitoes during evening operations throughout the City. The product is applied in a Ultra Low Volume (ULV) fog using less than 3 ounces of material per acre. The fogger produces droplets that are designed to float in the air for an extended period of time allowing the maximum contact with host seeking mosquitoes. Droplets are sized in the range of 10 to 30 microns.

Currently the product in use is Evoluer 4-4. This product contains 4% of the active ingredients Permethrin which is an insecticide; and 4% Piperonyl Butoxide which is a synergist that helps the insecticide work more effectively. The other 92% of the fog is a light mineral oil which is used as carrier to suspend the product in a cloud of droplets. All mosquito control products utilized in our program are approved for use by the US EPA and Wyoming Dept. of Agriculture.

Attached please find the product label and MSDS for Evoluer 4-4.

Please feel free to contact Keith Wardlaw, Mosquito Control Crew Supervisor, with any questions at telephone number 307-721-5258.”