Asilus crabroniformis

Range & Status

Widespread but declining in southern England, north to Cheshire and Lincolnshire, with most records from Hampshire, the south-west and south Wales.

Regional Distribution

Formerly widespread in Cornwall. Since 1980 recorded from only six localities: Mylor Bridge (1988 and 1989), St. Merryn (1987), Cadsonbury (1989), Downderry, Lansallos and Rame Head (all 1990), Trebray and Canaglaze near Altarnun (both 1995). The species was plentiful along Lansallos Cliff in 2006.

Habitat & Ecology

This impressive fly haunts warm localities. Adults hunt flies, bees, grasshoppers and other larger insects by swift flights from low vantage points, especially cow pats, from late June to early autumn. Larvae feed on dung beetle larvae in the soil beneath the pats.


Further loss of old pastures and grazing with livestock recently treated with certain dewormers.


Several sites on National Trust land are being managed for invertebrate conservation. A Priority Species under the UK Biodiversity Action Plan (2007).