Many solitary predatory wasps have to solve the problem of long-term storage of food items as provisions for developing offpsring. The European beewolf (Philanthus triangulum) supplies its larvae with immobilized honeybees as nourishment. The beewolf larva spins a cocoon and overwinters in a brood chamber, snug and warm, which are ideal growth conditions for microbes wishing to share its food cache.
The female beewolf daubs the chamber with a white substance extruded from glands in its antennae, and Kaltenpoth et al. have discovered that this exudate is the source of a Streptomyces bacterium, which, predictably, produces antibiotics that prevent microbial infestation and deterioration of the food supply. This symbiosis is analogous to that found in leaf-cutting attine ants, and as in that relationship, the Streptomyces are transmitted from mother to daughter wasp. If brood cells were not inoculated with the bacterium, larval survival fell from over 80% to less than 7%. Likewise, if a female beewolf fails to acquire the Streptomyces preservative, then it appears incapable of breeding successfully. -- CA
Curr. Biol. 15, 475 (2005).
