Pest Management Science (2021) 77, 3241-3249

Anabel Millán-Leiva, Óscar Marín, Krisztina Christmon, Dennis vanEngelsdorp and Joel González-Cabrera (2021)
Mutations associated with pyrethroid resistance in Varroa mite, a parasite of honey bees, are widespread across the United States
Pest Management Science 77 (7), 3241-3249
Abstract:
BACKGROUND
Managed honey bees are key pollinators of many crops and play an essential role in the United States food production. For more than ten years, beekeepers in the United States have been reporting high rates of colony losses. One of the drivers of these losses is the parasitic mite Varroa destructor. Maintaining healthy honey bee colonies in the United States is dependent on a successful control of this mite. The pyrethroid tau-fluvalinate (Apistan®) was among the first synthetic varroacides registered in the United States. With over 20 years of use, mites resistant to Apistan® have emerged, and so it is unsurprising that treatment failures have been reported. Resistance to tau-fluvalinate in US mite populations is associated with point mutations at position 925 of the voltage-gated sodium channel.
RESULTS
Here, we have generated a distribution map of pyrethroid resistance alleles in Varroa samples collected from US apiaries in 2016 and 2017, using a high throughput allelic discrimination assay based on TaqMan®. Our results evidence that knockdown resistance (kdr)-type mutations are widely distributed in Varroa populations across the country showing high variability among apiaries. We used these data to predict the phenotype of the mites in the case of treatments with pyrethroids.
CONCLUSION
We highlight the relevance of monitoring the resistance in mite populations to achieve an efficient control of this pest. We also put forward the benefits of implementing this methodology to provide data for designing pest management programs aiming to control Varroa.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Dennis vanEngelsdorp, Joel Gonzalez-Cabrera

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Varroa destructor		U.S.A. (SW)
	Varroa destructor		U.S.A. (NW)
	Varroa destructor		U.S.A. (mid N)
	Varroa destructor		U.S.A. (mid S)
	Varroa destructor		U.S.A. (NE)
	Varroa destructor		U.S.A. (SE)