Volucella inanis (Linnaeus, 1758)

Identification

Identification difficulty = 2. according to Ball & Morris, 2024¹

Biology

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.

Flight period

The following plots show the number of unique records per week that were not reported to be of eggs, larvae or pupae.

Status

Was listed as 'Notable' by Falk, 1991², but dropped from this status by Ball & Morris, 2014³ who consider it LOWER RISK.

Distribution

This species has undergone rapid range expansion since about 1995. 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.

Trends

The following plots show the Frescalo TFactor vs year and a map of the rescaled frequency (all records) for the species. For an explanation see here.