Report
Emergence of amitraz-resistant Varroa: what beekeepers should know and how to respond
Washington State University Extension fact sheet, 411E, Washington State University Extension
09/2026
DOI:
https://doi.org/10.7273/000008628
Abstract
Varroa destructor, or simply “Varroa,” is the most damaging pest of honey bee colonies worldwide. These ectoparasitic mites feed on honey bee adults and brood while vectoring deadly viruses. There are several approaches for beekeepers to manage Varroa including chemical, cultural, and mechanical controls. Chemical treatments include synthetic miticide (amitraz, tau-fluvalinate, coumaphos) and organic compounds (formic acid, oxalic acid, thymol, and hop beta acids). However, Varroa populations across the United States have developed resistance to tau-fluvalinate and coumaphos due to historic overuse of these ingredients and the persistence of those miticides in the wax. Additionally, there is growing evidence showing that the efficacy of amitraz is similarly dwindling due to the development of resistance. This phenomenon presents an urgent need for alternative control strategies to mitigate Varroa-associated honey bee colony losses. This Extension publication addresses the recent emergence of amitraz-resistant Varroa populations across the United States, describes how pesticide resistance develops, provides a method for beekeepers to test for amitraz-resistant Varroa themselves, and emphasizes ways to slow pesticide resistance development.
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Details
- Title
- Emergence of amitraz-resistant Varroa
- Creators
- Allyson Marie Martin (Author) - Washington State University, Department of EntomologyBriana Elizabeth Price (Author)Frank Rinkevich (Author) - United States Department of AgriculturePriyadarshini Chakrabarti (Author) - Washington State University, Department of EntomologyBrandon Kingsley Hopkins (Author) - Washington State University, Department of Entomology
- Academic Unit
- Publications, WSU Extension
- Series
- Washington State University Extension fact sheet; 411E
- Publisher
- Washington State University Extension; Pullman, Washington
- Identifiers
- 99901415703801842
- Language
- English
- Resource Type
- Report