Occupation dynamics and nesting behaviours ofXylocopa frontalis(Olivier) (Hymenoptera: Apidae) in artificial shelters

Abstract

We described herein the colonisation dynamics of trap-nests by females of the giant carpenter bee Xylocopa frontalis (Olivier). The behaviours performed by emerging females, such as philopatry and dispersal, were quantified in different environments and conditions of nest supply. Two artificial shelters containing high and low provision of trap-nests were installed in two areas to attract nesting females. It was detected a higher number of new foundations compared to nest reuse regardless the number of trap-nests provided. Full use of the available nests in shelters was not detected. Most of the emerging females dispersed from artificial shelter and the colonisation was made by both philopatric and vicinity females. No differences in the number of offspring produced by nesting females was observed among shelters but the number of brood cells in the newly founded nests was higher than that of the reused nests. The maximum span that a female remained in the shelter was 290 days. For dispersing females, the minimum permanence time in the shelter was 12 days ( $\bar{x}$ = 45 days). We conclude that the differences on availability of artificial substrates between the shelters was not sufficient to affect the number of constructed nests and the behaviours performed by nesting females. Additionally, it can be suggested that the higher number of dispersing females associated with the attraction of vicinity females can contribute to maximise the genetic variability of X. frontalis populations maintained in artificial shelters, aiming the management of this important pollinator in agro-ecosystems.