Consequences of coumaphos and Varroa destructor on drone honey bee sperm quantity

Abstract

The number of drones and genetic diversity among drones are essential components to a well mated queen. Varroa destructor preferentially parasitizes drone brood, and is thought to be responsible for the loss of feral populations that once provided additional drones for honey bee mating areas. It is necessary to use miticides (e.g. coumaphos) in managed colonies to control V. destructor. Little is known about the sublethal effects of these compounds, which are directly introduced into the hive. In response to growing concerns about the successful mating of honey bee queens, drone honey bees were exposed to coumaphos, during drone development. Sperm and seminal vesicles were sampled among drones that were exposed to coumaphos and drones that were not exposed to coumaphos, but were parasitized by Varroa destructor. There were no significant differences found between the two treatments in terms of seminal vesicle size and sperm numbers. These results indicate that drones parasitized by V. destructor have similar sperm quantities as drones exposed to coumaphos.