D3010: Evaluating the efficacy of permethrin-based applications for the control of Culicoides biting midges in Florida

The genus Culicoides includes many species that are a biting nuisance, and a number that transmit pathogens to animals and humans. Culicoides furens is a biting nuisance in coastal areas of Florida, negatively impacting tourism and limiting outdoor activities. Other Culicoides species such as C. sonorensis, C. venustus and C. insignis transmit viruses that cause hemorrhagic disease in ruminants. The control of Culicoides spp. relies on the use of insecticides for population management, raising concerns for the possibility of non-target effects and the development of insecticide resistance. We conducted laboratory and field experiments to evaluate the susceptibility of C. furens to permethrin applications. We developed a methodology to test insecticide susceptibility through field trials using screened cages and through CDC bottle bioassays in the laboratory. Live, wild-captured C. furens were obtained using modified CDC light traps and phototaxis chambers. Field experiments showed that wild local populations of C. furens are susceptible to Permanone 30-30 applied at maximum label rate. Laboratory experiments supported our findings, where technical grade permethrin at 10.75uL per bottle caused complete mortality within 30 minutes. Insecticide resistance to chemical insecticides is becoming a worldwide concern in blood-feeding dipterans. Our methodology can now be implemented to test for susceptibility and resistance of vector and nuisance species of Culicoides to determine whether current pest control techniques are effective, especially in livestock applications. Our results provide an opportunity to adjust current pest control strategies and create more sustainable and efficient methods for pest and vector control of Culicoides biting midges.