Location: Insect Behavior and Biocontrol ResearchTitle: Mechanisms of insecticide resistance in field populations of varroa mite (Acari: Mesostigmata: Varroidae)in Florida Author
|Legaspi, Jesusa - Susie|
Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/11/2016
Publication Date: 6/1/2016
Citation: Lambert, K., Marshall, K., Legaspi, J.C. 2016. Mechanisms of insecticide resistance in field populations of varroa mite (Acari: Mesostigmata: Varroidae)in Florida. Florida Entomologist. 99(2):324-326. Interpretive Summary: The ectoparasitic Varroa mite is currently the most serious threat to beekeeping worldwide. Without adequate control of Varroa mite infestations, honeybee mortality approaches 100% and colonies can perish within a few weeks. Miticide treatments remain the most cost-effective and widely used method of mite control for managed honey bee colonies however, resistance to the miticides is a growing concern. Scientists at the USDA, Agriculture Research Service, Center for Medical, Agricultural and Veterinary Entomology, Tallahassee, Florida, in collaboration with researchers from Florida A&M University, Tallahassee, Florida, assayed Varroa mites from northern Florida to assess the mechanisms of resistance to insecticides. Comparative studies on miticide toxicity identified the major mechanisms of resistance to organophosphorus and pyrethroid insecticides in Varroa mite populations. In contrast, other known resistance mechanisms were not found in the Varroa mites. Results from this study will aid in the identification of active miticides and development of resistance management strategies for the beekeeping industry.
Technical Abstract: The ectoparasitic mite Varroa destuctor is a serious threat to beekeeping and crops that rely on honey bee for pollination. The Varroa mite not only causes significant damage to honey bees by feeding on their haemolymph, but also serves as a vector of disease. In addition, the Varroa mite has developed resistance to the only two miticides (fluvalinate and coumaphos) registered for control of Varroa mite in the United States. The development of resistance in Varroa mite populations is a great concern to beekeeping; thus, there is an urgent need for strategies to manage that resistance. Comparative studies on miticide toxicity with or without the synergists piperonyl butoxide (PBO) and formamidine indicated that enhanced metabolism by mixed-function oxidases and altered target site were the major mechanisms of resistance to organophosphorus and pyrethroid insecticides in Varroa mite populations. In contrast, there was no synergism with S,S,S,-tri-n-butyl phosphorotrithionate, triphenyl phosphate (DEF), diethyl maleate (DEM), and and triphenyl phosphate (TEPP). Therefore, esterase, glutathione-S-tranferase, and carboxylesterase were not important mechanisms of resistance in Varroa mite.