DISSERTATION RESEARCH: Social Evolution in Carpenter Bees

University Of Utah, Salt Lake City UT

Investigators

Abstract

Female carpenter bees often reproduce alone, but some individuals form pairs and reproduce cooperatively. A puzzling division of labor occurs in these pairs: one female does all the foraging and lays most or all of the eggs, while the other female guards the nest. Why does a guard help another female to reproduce, while forgoing her own reproduction? And why does a reproductive forager allow an apparently unrelated female to live in her nest? This study will use field observations, behavioral experiments, and genetic analyses to address these questions. Carpenter-bee nests are excavated in solid wood; they are expensive, but durable. A female who inherits a nest (rather than building one) may save valuable time and energy. This study will ask whether guards preferentially join nests that they seem likely to inherit. The question is of general interest because resource inheritance has been shown to favor the formation of social groups in birds and mammals; this study may produce the first convincing evidence that resource inheritance has similar effects on the social systems of insects. More generally, this study will increase basic factual knowledge of North American carpenter bees which remain poorly known despite their large size and striking beauty.