Mating behavior of the black carpenter bee Xylocopa sulcatipes (Hymenoptera: Apidae)
Miriam Rosenboim
The courtship and mating behavior of Xylocopa sulcatipes is reexamined and described here. The study sought to determine whether a courted female may already be mated or is still virgin, and whether females are selective or not, with emphasis on precopulatory behavior and possible mate selection. All the observed copulations in the study were preceded by grasping behavior, in which the male holds the female by the legs. Eighty-five percent of females caught during the grasping behavior were virgin, as indicated by their empty spermatheca. The duration of grasping behavior by smaller males was short, suggesting their immediate rejection by the female; whereas a prolonged grasping behavior in larger males tended to end in copulation. The new behavior described here – grasping behavior – is interpreted as providing a mechanism for inspection of the male by the female prior to mating. It is suggested that without an 'I am ready' signal from the female the sequence of grasping that leads to copulation will not proceed, implying that females can prevent the sequence and thereby manipulate inter-sexual selection.