Sexual selection in Apis beesBoris Baer
Institute of Biology, Department of Population Biology, Universitetsparken 15, 2100 Copenhagen, Denmark
(Received 18 October 2004 - revised 13 December 2004 - accepted 13 December 2004; Published online: 1 June 2005)
Abstract - Honey bees in the genus Apis share many reproductive features with other social insects, but have also a number of highly derived mating characteristics, such as obligatory polyandry and - in at least two species - males who deposit their ejaculates directly into the spermathecal duct. These characteristics make the honeybees highly interesting and a special model system for studying sexual selection. Furthermore, the numerical sex ratio of Apis bees is extremely male biased and males die during their first and only copulation. This review updates our present knowledge of the mating biology of Apis bees and places this information into a broader concept of sexual selection. I concentrate on two intensively studied aspects of sexual selection: Sperm competition and cryptic female choice. I present evidence that sperm competition is likely to occur during the egg fertilization process, whereas cryptic female choice is likely to operate shortly after insemination when ejaculates of many males get stored in the spermatheca of the queen.
Key words: Apis / honeybee / polyandry / sperm storage / sperm use / sperm competition / cryptic female choice
Corresponding author: Boris Baer BCBaer@bi.ku.dk
© INRA, DIB-AGIB, EDP Sciences 2005