Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/20/2004
Publication Date: 10/20/2004
Citation: DeGrandi-Hoffman, G., Chambers, M., Hooper, J.E., Schneider, S.S. Description of an intermorph between a worker and queen in African honey bees Apis mellifera scutellata (Hymenoptera: Apidae). Ann. Entomol. Soc. Am. 2004. 97:1299-1305.
Interpretive Summary: Honey bee queens and workers are produced from fertilized eggs. Any fertilized egg has the potential to become a queen or worker. The quantity and composition of food given to a larva during the first 3 days of its life determines its caste. If the larva is fed exclusively on a nutrient-rich secretion from the workers' hypopharyngeal glands, it will develop into a queen. A worker bee will develop if a larva is fed the secretion for only the first 2 days of its life and then is fed pollen and nectar. While most female honey bees are exclusively workers or queens, we have discovered females in African honey bee colonies that have characteristics of both. We call these females intermorphs. Intermorphs resemble workers in body size and the shape of their head and mandibles. However, intermorphs are queen-like in the shape of their thorax and abdomen, and in the distribution of hairs on their body. The most interesting feature about intermorphs is that the volatile compounds (i.e., odors) they emit are similar to those of a queen. We speculate on how intermorphs might influence worker-queen interactions and possibly influence the invasion of European honey bee colonies by African bees.
Technical Abstract: We have found bees with characteristics of both workers and queens in African honey bee (Apis mellifera scutellata) colonies and in African usurpation swarms in the southwestern U.S. We also found the intermorphs in colonies of European honey bees (Apis mellifera) into which, because of their cuticular color, we assume they drifted. The intermorphs are similar to workers in the shape of their head and mandibles, weight, body length, and the width of their thorax. Intermorphs have corbiculae that are similar to those of workers and do not have developed ovaries or enlarged spermathecae. However, intermorphs physically resemble small virgin queens because of the shape of their abdomens and the number and distribution of hairs on their bodies. Intermorphs also emit volatile compounds that are similar to those emitted by queens but different from those emitted by workers. We speculate on the role of intermorphs in affecting worker-queen interactions especially in usurpation swarms of in queenright European colonies where they might enter from nearby African hives.