; order Diptera, suborder Brachycera)
Family of flies, most of which are medium to large, with densely pubescent bodies and slender legs. The proboscis is elongate, points forward, and is adapted for feeding on nectar from flowers with long corollas. The third antennal segment is simple, with the style small or absent. Their common name refers to their appearance and adult behaviour, and to their larvae which are parasitic upon bees and wasps, although some species have larvae which parasitize other insects. Eggs are laid near the entrance to the nest of the specific bee host parasitized by that species of bee-fly. The tiny larvae enter the nest and usually wait until the bee larva has pupated before metamorphosing from a small, mobile animal to a smooth, fat larva which feeds on the bee pupa. The bee-fly pupa is dual-phased. The first pupa is ‘normal’; the second stage has a sharp battering ram with which to break down the nest cell wall, made by the adult bee when closing the cell. The adult bee-fly emerges once the second stage pupa has ruptured the seal. More than 2000 species of bee-flies have been described.
Subjects: Zoology and Animal Sciences.