Volucella inanis (Linnaeus, 1758)
Biology & ecology:
The larva is an ectoparasite of social wasp larvae, and has been found in association with Vespula germanica and Vespa crabro. They are, unlike any other member of the genus, very flattened so that they fit into the larval cells beside the wasp grubs on which they feed. Found in open areas in woodland and scrub and, most frequently, in suburban areas, in parks and gardens. Adults are usually seen visiting flowers, especially white umbels and the Butterfly Bush Buddleja davidii.
This species has undergone rapid range expansion in the past 20 years. This expansion has been most marked on the eastern side of England. The loss of range in the south west during the 1960s has not yet fully recovered, although there are signs that this is now happening. The main population was formerly centred on London and counties to the south and east but today it occurs north to West Yorkshire. This is one of a small suite of species that are responding to warmer summers and winters.
Status & conservation:
This species has undergone a rapid increase in frequency corresponding to considerable range expansion since the early 1990s (Morris & Ball, 2004a).