Eupeodes nielseni (Dušek & Láska, 1976)
Metasyrphus nielseni Dusek & Laska in Stubbs & Falk (1983).
Biology & ecology:
The larva is predaceous upon aphids and adelgids on Larch Larix and Scots Pine Pinus sylvestris. Adults are flower visitors. The main centre of population in Scotland seems to have been Caledonian pinewoods, but today that link is much weaker as E. nielseni now occurs in a wide range of conifer woodlands.
There are two very distinct populations, one in the Scottish Highlands; the other in Dorset. There are also scattered records across England, Wales and Southern Scotland that suggest that this species is more widely distributed than current data suggest.
Status & conservation:
The frequency of occurrence is very variable, but there is evidence of a decline over the last decade.