I want to share with everyone a recent development concerning product use in the statewide West Nile Integrated Mosquito Management Program. The Pennsylvania Department of Environmental Protection (DEP) has just recently finished efficacy testing on a reduced risk pesticide that is even less toxic than the permethrin products.
What does a county-wide IPM program for mosquitoes look like?
Like any IPM program, it relies on knowledge of the target pest, routine surveillance to monitor populations, establishment of thresholds for control operations, and ultimately, pesticide measures, when those thresholds are exceeded, while employing techniques and products that cause minimal risk to the environment and non-target organisms.
Basic knowledge of the mosquito’s life cycle gives us the most effective mechanism to control their populations. All mosquitoes require water to complete their life cycle. Female mosquitoes lay their eggs either on or near water. The eggs hatch in the water, where the larvae grow through four stages called instars, before pupating and hatching into a winged adult.
The new products are based on the active ingredient Etofenprox, another synthetic pyrethroid. According to DEP, the cost is comparable (about 18% more expensive), efficacy is satisfactory, and no synergists (additives) are needed. The chart1 below demonstrates the reduced toxicity. Resmethrin is closest in comparison to the permethrin we talked about earlier. The chart also compares the relative toxicity of some common household chemicals like salt (sodium chloride), caffeine, and aspirin (salicylic acid). The higher the LD50, the lower the toxicity of the compound being tested. As a result of the testing, DEP will be migrating to use of Etofenprox products in the future.