Abstract:
In dequeened honeybee colonies ovarian activation occurs in some workers,
and the pheromonal bouquets of these laying workers become more queen-like. In the
Asiatic honeybee, Apis cerana, we compared the amounts of 9-keto-2(E)-decenoic acid
(9-ODA), a mandibular gland pheromone component, between non-laying workers from
queenright colonies and laying workers from queenless colonies and, further, applied
synthetic 9-ODA to workers to determine whether workers discriminate workers with
activated ovaries based on the level of this compound. Levels of 9-ODA were higher in
laying workers from dequeened colonies than in non-laying workers from queenright
colonies. In both queenright and queenless colonies, more workers treated with 9-ODA
were attacked by other workers than were control-treated workers. These results suggest
that detection of pseudoqueens in A. cerana is mediated by changes in 9-ODA.
