Dallas County is expected to begin aerial spraying of adulticide this week in an attempt to curb the mosquito population and stall the spread of West Nile virus in the county.
They have contracted with an environmental products company, Clarke, who will be using an adulticide called Duet.
Duet is an EPA-approved pesticide comprised of two active ingredients -- Sumithrin and Prallethrin. Both ingredients are pyrethroids, or synthetic chemical insecticides, designed to mimic the natural pyrethrins extracted from chrysanthemum flowers.
Pyrethrins are naturally-occurring organic neurotoxins that attack the nervous systems of all insects, eventually killing them.
Since the product is sprayed at night, when mosquitoes are flying, beneficial insects such as bees and butterflies, who are dormant at night, should not be impacted. Additionally, pyrethroids are biodegradable, breakdown upon exposure to light and oxygen and degrade rapidly.
A cumulative risk assessment conducted by the EPA in Oct., 2011, indicated exposure to pyrethrins and pyrethroid insecticides does not pose a risk to children or adults. Additionally, the EPA said there does not appear to be a clear relationship between pyrethrins/pyrethroid exposure and asthma/allergies.
Duet will be dispersed from an altitude of 300 feet by Beechcraft King Air twin prop planes in quantities of .8 ounces per acre. The low volume translates to a fine mist of tiny drops, where the average droplet is 17 microns -- or smaller than the size of a pinhead.
According to the EPA, "pyrethrins and pyrethroids are insecticides included in over 3,500 registered products, many of which are used widely in and around households, including on pets, in mosquito control, and in agriculture."