Evidence of entrance sharing and subterranean connections in Andrena agilissima (Hymenoptera; Andrenidae)

Andrena agilissima is a bee that nests on sloped or vertical earth walls. D ata from 3 years of fieldwork presented here show that this species is comm unal and uses the same nesting site for many years. On an earth wall on Iso la d'Elba (Tuscany, Italy), covered with many bee nest entrances, we studie d an aggregation of Andrena agilissima to determine if bees share entrances , if the sharing provides evidence for subterranean connections, and if bee s involved in sharing show a division of labor. We marked several females c oming out of the same entrance, as well as recapturing the same females usi ng different entrances. No division of labor was observed in our observatio ns.