Drone cell cappings of Asian cavity-nesting honey bees (Apis spp.)

Abstract

Drone pupae of Apis cerana are sealed in their cells under a hard silken cap with a central pore, a feature notably lacking in the closely related species, Apis nigrocincta. In this paper, the hard cap with a pore is confirmed for drone cells of four additional species or putative species of cavity-nesting honey bees of Asia. Inaccuracies in the literature related to cell cappings of Asian bees are clarified. The character state of the drone cell cap for each taxon was added to a recent phylogeny for the genus Apis. Parsimony analysis indicates that the hard cap evolved once in the common ancestor to all Asian cavity-nesting honey bees and was subsequently lost in Apis nigrocincta. Possible functions of the hard drone cell cap are reviewed, but the true functions of the cap and the reasons underlying its loss in A. nigrocincta remain unresolved.