Efficacy of Three Pyrethroid Insecticides in Suburban Mosquito Suppression

Mosquito-borne diseases have exhibited high profile outbreaks in the Americas recently. Locally-acquired Chikungunya Virus, vectored by both Ae. aegypti and Ae. albopictus, was reported for the first time in the Western Hemisphere in December 2013 on the Caribbean island of Saint Martin, and the United States reported multiple locally-acquired cases of Dengue Fever Virus from Ae. aegypti mosquitoes in southern Texas, Florida, and one isolated case in Long Island, New York. Additionally, hundreds of human cases of WNV were reported in the Dallas-Ft. Worth area of Texas in 2012. These outbreaks have caused heightened perceived disease risk by the public, thus creating a demand for suburban mosquito control services. To investigate the efficacy of such control programs in Kentucky, I compared the efficacy of three different approved mosquito control residual pyrethroids in homeowner backyards (Demand™ CS, Suspend Polyzone™, and Tandem™), along with Demand™ CS and Arilon™ in field plots. Mosquito populations were monitored weekly for six weeks after treatments using standard CO₂-baited CDC traps. In suburban backyards, Demand™ and Tandem™ significantly reduced mosquito numbers compared to Suspend™. In the field trials, Arilon™ proved comparable to Demand™, and could be a possible contender for future mosquito control programs. For all experiments, mosquito control was less than expected, at 60-70%, when previous efforts have shown >80% control, possibly due to the unusual cool and wet spring of that year. Despite the low percentage of control, homeowner satisfaction surveys were positive, but with a strong placebo effect.