Large-Scale Monitoring of Resistance to Coumaphos, Amitraz, and Pyrethroids in Varroa destructor

Abstract

Varroa destructor is an ectoparasitic mite causing devastating damages to honey bee colonies around the world. Its impact is considered a major factor contributing to the significant seasonal losses of colonies recorded every year. Beekeepers usually rely on a reduced set of acaricides to manage the parasite, usually the pyrethroids tau-fluvalinate or flumethrin, the organophosphate coumaphos, and the formamidine amitraz. However, the evolution of resistance in the mite populations is leading to an unsustainable scenario with almost no alternatives to reach an adequate control of the mite. Here, we present the results from the first large-scale and extensive monitoring of the susceptibility to acaricides in the Comunitat Valenciana, one of the most prominent apicultural regions in Spain. Our ultimate goal is to provide beekeepers with timely information to help them decide what would be the best alternative for a long-term control of the mites in their apiaries. Our data show that there is a significant variation in the expected efficacy of coumaphos and pyrethroids across the region, indicating the presence of a different ratio of resistant individuals to these acaricides in each population. On the other hand, the expected efficacy of amitraz was more consistent, though slightly below the expected efficacy according to the label.

Green Veterinary Pharmacology for Honey Bee Welfare and Health: Origanum heracleoticum L. (Lamiaceae) Essential Oil for the Control of the Apis mellifera Varroatosis

“…In recent years, the phenomena of drug resistance are becoming more and more widespread. Essential oils can be a valid alternative to synthetic acaricides for the control of varroatosis in beekeeping [ 21 , 22 , 24 , 67 , 68 ]. Essential oils are environmentally friendly and, as their mechanisms of action are involved in different molecular pathways, it is rare for treated parasitic populations to develop resistance mechanisms.…”

“…The identification of alternative methods for the control of V. destructor becomes urgent, also in the light of the increasingly and widespread phenomena of drug resistance reported [ 21 , 22 , 23 , 24 , 25 ]. Control methods based on the use of essential oils offer considerable promise due to their low toxicity to humans and the environment [ 26 ].…”

In Vitro Evaluation of Acute Toxicity of Five Citrus spp. Essential Oils towards the Parasitic Mite Varroa destructor

“…In addition, V. destructor is rapidly developing drug resistance, which is now increasingly reported. Resistance to the main synthetic acaricides, such as fluvalinate, has been well documented, and drug resistance to Amitraz is becoming widespread [ 20 , 21 , 22 , 23 ].…”

Entomopathogenic Fungi for Pests and Predators Control in Beekeeping

“…Parasites, particularly V. destructor and predators, represent a serious threat to the health, welfare and productivity of A. mellifera worldwide [150,151] and they are the main causes of the significant hive losses for beekeeping globally [152]. Currently, the control of parasites is mainly based on the use of chemical drugs [153].…”