Wasp hoverfly  (Doros profuges)

Classified as Vulnerable in Great Britain (3).

This spectacular large, slender hoverfly is a wasp mimic; its body shape and black and yellow markings make it very similar in appearance to a wasp (4). The 'model' for this mimicry is thought to be the solitary wasp Argogorytes mystaceaus. The hoverfly receives protection as a result of this mimicry, as potential predators believe that it is either able to sting or is extremely distasteful (5).

Since 1990 only a few sites in Great Britain have been found to support this species (5). Most of these are in the south and southeast of England (5). It has also been found in Scotland on Arran and the Isle of Mull (6). The range of this hoverfly extends from southern Norway and Finland down to central Spain, and from Ireland extending east through much of central and southern Europe, through Eurasia, reaching the Pacific coast, encompassing Japan and China (5).

The wasp hoverfly seems to prefer woodland edge or scrubby habitats; in England all of the occupied sites feature flower-rich calcareous grassland, where there are ant mounds, and bramble (Rubus species) present. Most sites are on south-facing slopes or in sheltered valleys, suggesting that the hoverfly is 'thermophilous', literally 'heat-loving' (5).

Little is known of the biology of this species; the life history is largely a mystery but it seems likely that it is complex and specialised (6). Adults fly in June, males are rarely seen, and females fly only in sunny conditions (5). Evidence suggests that the larvae are predatory, and it has been speculated that they may be associated with the ant species Lasius fulginosus, feeding on aphids that the ants have herded (5).

Although the factors responsible for the decline of this species are not known (6), it is thought that habitat loss and alteration through human activity may be important (5).

The wasp hoverfly is a UK Biodiversity Action Plan (UK BAP) priority species, and a Species Action Plan has been produced to aid its conservation. This plan aims to maintain the current populations, and to increase the size of these populations before 2010 (6). Many of the current populations occur within Sites of Special Scientific Interest (SSSIs) (6), and English Nature has funded research and survey work on this species (5).

Information authenticated by Jon Webb, English Nature:
http://www.english-nature.gov.uk/

• Calcareous: containing free calcium carbonate, chalky.
• Larvae: stage in an animal's lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.

1. National Biodiversity Network Species Dictionary (August 2002) http://www.nhm.ac.uk/nbn/
2. Jon Webb (2002) Pers Comm.
3. Shirt, D. B. (Ed) (1987) British Red Data Books: 2. Insects. Nature Conservancy Council.
4. Levy, E.T. & Levy, D.A. (1998) Somerset Hoverflies. Diptera Recording Scheme.
5. Plant, C. W. (1999) The wasp hoverfly Doros profuges (Harris). Report of the 1999 survey. English Nature Research Report number 352. English Nature, Peterborough.
6. UKBAP (August 2002): http://www.ukbap.org.uk