Meeting Abstract
A mark-recapture study of carpenter bee (Xylocopa) species at chasteberry bushes (Vitex agnus-castus) was conducted on the island of Lesvos (Greece). Bees were color-coded with paint marks so as to identify their capture sites; collections were repeated during a comparable period of time on subsequent days. White and blue morphs of the bushes of this plant species were specifically compared with one another to detect a preference by carpenter bees for either color. Although return rates were too low to detect significant differences in foraging fidelity by any carpenter bee species, we did note that, during our collection efforts, three species of carpenter bees foraged in a manner that suggests they have differing circadian rhythms: matinal, diurnal and/or crepuscular. Our results most likely reflect differences in spatial and temporal foraging scales wherein the relatively large-bodied and strong-flying carpenter bees traverse greater distances during the earlier and later periods of the day in order to avoid intense heat. The smallest species, Xylocopa violacea, was collected more often during the heat of the day while the remaining species, Xylocopa oliveri, visits only very early or very late in the day. These findings may have implications for understanding how body size relates to foraging times and as a thermoregulatory response to daily temperature cycles. Indeed, we predict that the circadian rhythm cycles endogenous to the bees will reflect their foraging habits.
