Title: Varroa Sensitive Hygiene and Drone Brood Author
Submitted to: American Bee Journal
Publication Type: Abstract Only
Publication Acceptance Date: February 15, 2008
Publication Date: June 1, 2008
Citation: Harris, J.W. 2008. Varroa Sensitive Hygiene and Drone Brood. American Bee Journal. 148(6):556-557. Technical Abstract: Honey bees have been bred to express high levels of varroa sensitive hygiene (VSH), which is the removal of mite-infested pupae from capped worker brood. This hygienic behavior is a complex interaction of bees and brood in which brood cells sometimes are inspected, and then brood is either removed (especially if diseased or varroa infested) or recapped (especially if healthy). Previous work has shown that VSH bees uncap and remove significantly more varroa-infested worker pupae than do non-hygienic bees (Harris, 2007 J Apic Res 46: 134-139), but nothing is known about the reactions of VSH bees towards mite-infested drone brood. This study compared the reactions of VSH bees to mite-infested worker and drone brood in a field test. Brood combs of both types were chosen so that the majority of host pupae had untanned bodies and non-pigmented eyes. The infestation rate for each comb was estimated before and after placing it into the center of the broodnest of a VSH colony for 1 week. Each colony was given a comb of worker brood; followed by a comb of capped drone brood within 1-2 weeks of the first trial. Results indicated that VSH bees inspected brood cells containing mite-infested drone pupae, but they did not remove significant numbers of pupae from cells (Figure). Some hygienic responses (e.g. uncapping of mite-infested pupae) were positively correlated to an increasing initial infestation rate in worker brood, but there were no correlations between initial infestation and hygienic responses to drone brood. These results suggest that mite populations in VSH colonies could increase more rapidly when drone brood is available.