Chrysotoxum arcuatum (Linnaeus, 1758)
Biology & ecology:
The larva has been found feeding on root aphids associated with ant nests. They are not easy to find, and the best time to search for them is at night (Rotheray, pers. comm.). Occurs widely in upland and moorland locations in unimproved grassland with scrub and in grassy openings in woodland. Adults fly low among ground vegetation and visit a wide range of flowers in sheltered situations.
A strictly northern and western species, locally frequent north of a line from the Severn to the Humber, although there is a confirmed record from the Brecklands of Norfolk.
Status & conservation:
There has been a general decline in occurrence over the past 30 years.
Recorded from 440 hectads since 1990.