Platycheirus ambiguus (Fallén, 1817)
Placed in Melanostoma by Coe (1953), but more recently placed in the sub-genus Pachysphyria within Platycheirus.
Biology & ecology:
The larva is unknown. Adults fly early in the season, peaking in late April, and are most often found visiting Blackthorn Prunus spinosa blossom, but also at other flowering shrubs. Both sexes can be found hovering about the flowers where bushes are in sunny and sheltered situations.
Most records are from the southern half of England, but it does extend into Wales and Scotland.
Status & conservation:
This is rather a local species, but it can be abundant where it occurs. It may be under-recorded because of the early flight period. Trend analysis highlights a significant decline in occurrence.