Comparisons of the queen volatile compounds of instrumentally inseminated versus naturally mated honey bee (Apis mellifera) queens

Authors: Huang, Ming; DeGrandi-Hoffman, Gloria; Le Blanc, Blaise

Submitted to: Apidologie
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/12/2008
Publication Date: 7/20/2009
Citation: Huang, M.H., Hoffman, G.D., Le Blanc, B.W. 2009. Comparisons of the queen volatile compounds of instrumentally inseminated versus naturally mated honey bee (Apis mellifera) queens. Apidologie 40:464-471.

Interpretive Summary: Instrumental insemination of honey bee queens is an attractive alternative to naturally mated queen because favored traits can be selected for such as increased mite resistance, pollen collection, and nest hygiene. In spite of these benefits, there is ongoing debate on whether the chemical profile of instrumentally inseminated (II) queens is different from naturally mated (NM) queens, thus affecting their acceptance rate in colonies. The objective of this study was to determine whether the chemical profile (specifically volatile compounds) of virgin queens changes as they develop into mated egg-laying queens. Then, we determined whether the volatile compounds given off by II queens differ from NM queens. Our results show that there were greater amounts of seven volatile compounds detected in virgin queens compared with mated egg-laying queens. The higher expression of volatile compounds in virgin queens may be important for the initial selection process for replacement queens. In contrast, mated eqq-laying queens have greater amounts of the queen-specific compound E-B-ocimene than virgin queens, which may be important for continued acceptance. II and NM queens share a similar volatile chemical profile as they develop from virgin queens to mated egg-laying queens. These similarities suggest that the physiological changes occurring after mating and egg laying proceed normally regardless of the queen's method of mating.

Technical Abstract: Instrumental insemination is an attractive alternative to natural mating because specific genetic crosses can be made, thus producing colonies with desired traits. However, there are conflicting reports on the quality and acceptance of instrumentally inseminated (II) queens compared to naturally mated (NM) queens. One factor that affects acceptance and retention of queens is the volatile compounds they produce. Our study compares volatile chemicals from virgin and mated honey bee queens that are either NM or II. The volatile compounds from virgin queens differed from those of mated egg-laying queens. Virgin queens produced greater amounts of the volatile compounds we detected (including 2-phenylethanol, n-octanal, and n-decanal) with the exception of E-B-ocimene, which was higher in mated laying queens. II and NM queens did not differ in type or relative amounts of volatile compounds. The similarities between II and NM queens indicate that the physiological changes that happen after mating and egg laying occur regardless of the mating method.