Body size, loading capacity and rate of reproduction in the communal bee Andrena agilissima (Hymenoptera; Andrenidae)

Abstract

In bees, body size may be particularly important in determining the loading capacity, and consequently the rate of reproduction. We studied a population of Andrena agilissima (Hymenoptera: Andrenidae) in Italy, weighing provisioning females, load being carried and pollen provisions. We found no correlation between adult body size and loading capacity. Weight of pollen collected per trip did not vary across the day, while weight of nectar collected increased in the afternoon. The amount of nectar being carried was independent of the amount of pollen. The A. agilissima rate of reproduction resulted in less than 1 provision mass produced per day (3.6 offspring/female per season). This result is consistent with observations in other Andrena species which suggests a phylogenetic constraint in the rate of reproduction that merits further study. © INRA/DIB-AGIB/ EDP Sciences, 2005.