Pat Wright, SC DHEC
The Charleston County Mosquito Abatement Program uses malathion and Dibrom as two of its most important products for controlling adult mosquitoes and managing resistance. A third product is used as well. The loss of these would cause significant control problems and would be costly.
There is currently some resistance to malathion in some mosquito species. By using different products including malathion, resistance is being managed.
The loss of malathion and Dibrom would result in very few products being available. Only two products, Sumithrin and Resmethrin, would be available to use due to availability and environmental concerns. Resmethrin has not shown to be consistently effective in controlling Aedes taeniorynchus, a salt marsh mosquito that is the biggest pest mosquito from mid-June through mid-October.
With only two products to use, and one not consistently effective on the major pest mosquito, resistance management becomes very difficult.
Approximately 75,000 acres are treated by air with malathion per year and 600,000 acres with Dibrom through ground treatment. If other products are used, it will cost the tax payers of Charleston County a minimum of $100,000 per year plus the inability to manage for resistance properly.
TO: Bob Bellinger
FROM: Sue C. Ferguson
Richland County Environmental Health Services
SUBJECT: Potential Impact on Mosquito Control Services re: Loss of Organophosphate Insecticides
Pat Wright spoke with me and requested that I provide you with a few comments relative to the referenced subject. This is by no means an "in-depth" analysis, just those things that readily come to mind.
I hope these comments are along the lines of what you wanted. If you have any questions, please Email me or give me a call at (803) 748-4995.