Chrysotoxum octomaculatum Curtis, 1837
Collin (1940) split this species to recognise C. verralli which is actually the commoner of the two species. Early records should be discounted unless supported by a voucher specimen.
Biology & ecology:
This is a heathland species. The larva is probably associated with ant-tended root aphids. Adults are noted as flower visitors, having been taken at buttercups Ranunculus sp. and Rhododendron.
There appear to be two discrete populations, one in Dorset (Hartland Moor, Gore Heath and Newton Bay), the other in Surrey (Thursley & Hankley Commons) and there are recent records from both areas. There are also records from Cornwall and Essex that may refer to this species, but they are old and may in fact prove to have been Chrysotoxum verralli.
Status & conservation:
Very few, sporadic records.