Parasitization of honey bees (Apis mellifera) by the mite Varroadestructor is one of the main culprits of honey bee health decline. To begin its reproductive cycle, a gravid female mite enters the comb cell of a bee pre-pupa just before its comb cell is capped. The mite then undergoes development and reproduction within the cell, after which her offspring exit the cell as the adult bee emerges. Because drones take longer to pupate, they are preferred by mites in the reproductive phase so as to increase the number of offspring. Interestingly, the main difference between V. destructor invasions in colonies of their original host, Apis cerana, and its introduced host, Apis mellifera, is that the mites invade and successfully reproduce in worker larval cells of A. mellifera (but not A. cerana), thus increasing by orders of magnitude the number of potential cells in which to complete their reproductive phase. In this study, we examined whether worker brood in A. mellifera is differently at risk for Varroa mite invasion with increased proximity to drone brood. We also compared the size (wet weight) of worker and drone brood at different stages of development based on whether their cells were invaded by zero, one, or multiple Varroa mites. Understanding the distribution of Varroa mites in the broodnest area, particularly around worker brood, as well as how mite feeding impacts brood development, will give us a better picture of the impact of Varroa parasitization on honey bee colonies.
