Oxalic acid options for controlling Varroa destructor

Varroa destructor is a globally distributed ectoparasitic mite that is a leading driver of honey bee colony losses in the United States. Varroa was introduced into the US in the 1980s. Since then, these mites have detrimentally impacted honey bee colonies all over the country; direct and indirect effects of Varroa infestations are a major contributor to honey bee colony losses each year. There are inherent challenges with successful Varroa management since available options vary in suitability during honey bee population phases such as little to no brood production over winter or prolific brood production in spring. Therefore, beekeepers should intensively manage their honey bee colonies with various integrated pest management (IPM) tools to keep mite populations below damaging levels. Varroa destructor cannot be eradicated, so control measures must be performed using a sustainable, more wholistic approach, such as using IPM strategies. This publication aims to focus on one Varroa management option, oxalic acid. In addition to describing all currently available, commercial oxalic acid products that have been approved by the United States Environmental Protection Agency (EPA), this publication also compares their delivery methods. Beekeepers can use this publication to make informed Varroa mite oxalic acid management decisions.