Helophilus affinis Wahlberg, 1844
Biology & ecology:
The larva is not described. According to Speight (2010), it is associated with small water bodies in unimproved grassland, acid fen and the edge of raised bogs. Adults hover over small pools.
This species was added to the British list by Stuke (1996), based on a single specimen in the Royal Museum of Scotland collected by A.B. Duncan in August 1982 on Fair Isle, and originally identified as H. hybridus. It has been rapidly extending its range southwards from Scandinavia and northern Europe in recent decades. It has been recorded regularly from Denmark (previously only isolated specimens), and for the first time in the Netherlands and NW Germany since 1980 and recently in SW Germany and Switzerland (Speight, 2010). Speight (1988) predicted its occurrence in Britain, and gives a key to separate it from the other British members of the genus.
Status & conservation:
Recorded from 1 hectad prior to 1985.