Title: Expression of varroa sensitive hygiene (VSH) in commercial VSH honey bees (Hymenoptera: Apidae) Authors
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 16, 2011
Publication Date: June 1, 2011
Citation: Danka, R.G., Harris, J.W., Villa, J.D. 2011. Expression of varroa sensitive hygiene (VSH) in commercial VSH honey bees (Hymenoptera: Apidae). Journal of Economic Entomology. 104(3):745-749. Interpretive Summary: Varroa mites are a worldwide threat to honey bees. Mite parasitism can be managed by keeping bees that have at least moderate levels of the behavioral trait called varroa sensitive hygiene (VSH). VSH is a product of our laboratory that currently is delivered to the beekeeping industry with a cooperative agreement with a commercial queen breeder. The cooperator creates breeder queens that are sold to queen producers who then make open mated production queens. The level of VSH in such end-user production queens has not been measured previously. We tested the expression of VSH in production queens from six commercial sources. Levels of removal of mite infested brood, the principal action of VSH, on average were intermediate in the commercial sources (45% reduction in infested brood). This was less than in pure VSH (82%) and in breeding material distributed by the cooperator (64%), but was greter than in unselected bees (7%) commonly used by U.S. beekeepers. Supplying VSH drones for matings with VSH queens would improve overall mite resistance. Nonetheless, this intermediate level of VSH is consistent with other outcross colonies we have tested and that performed well. Expression of VSH was variable both within and between commercial sources. Beekeepers are cautioned to monitor levels of mites because of this variability
Technical Abstract: We tested six commercial sources of honey bees (Apis mellifera L.) that were bred to include the trait of varroa sensitive hygiene (VSH). VSH confers resistance to the parasitic mite Varroa destructor Anderson & Trueman. Queens from these sources were established in colonies which later were measured for VSH and were compared to colonies with queens of the original ARS breeding source, queens from the commercial distributor of VSH bees and queens of a commercial, mite-susceptible source not bred for VSH. The reduction of mite infestation in brood combs exposed to test colonies for one week differed significantly between groups. On average, commercial VSH colonies reduced infestation by 46%, intermediate between pure ARS VSH (76%) and unselected control colonies (7%). Commercial VSH colonies from different sources varied in their hygienic response. Mite infertility was high in remaining infested cells in ARS VSH, but lower and highly variable in other sources of VSH or control colonies. Bee breeders and beekeepers should use material as close to highly selected VSH colonies as possible to guarantee high levels of resistance to mites.