Nesting and life cycle of the Australian green carpenter bees Xylocopa (Lestis) aeratus Smith and Xylocopa (Lestis) bombylans (Fabricius) (Hymenoptera : Apidae : Xylocopinae)

This paper expands on previous observations of Australian green carpenter b ees by providing information about nesting substrates and the life cycle of Xylocopa (Lestis) aeratus and Xylocopa (Lestis) bombylans from more than 4 50 colonies from South Australia and New South Wales. Voltinism differs bet ween the two species, but does not appear to vary within species from diffe rent locations, such as X. aeratus colonies on Kangaroo Island, South Austr alia acid at Woy Woy, New South Wales. The architecture of nests (unbranche d or branched) is related to the substrate diameter and may allow variation in social behaviour because different provisioning strategies can be used in the two nest types. Both species have some multifemale colonies for most of the year and this includes the brood-rearing period. Differences in vol tinism, nest type and the occurrence of multifemale colonies during brood p roduction are likely to lead to variation in social organisation within and between species.