Sphegina sibirica Stackelberg, 1953
Biology & ecology:
Larva unknown, but females have been observed ovipositing on the underside of a cut Spruce Picea trunk lying across a stream (Speight, 2010). In continental Europe, adults are found in Picea forests along the edges of paths and streams, where they often hover around freshly cut logs (Speight, 1988). The majority of records in Britain come from grassy areas and stream-sides in or near conifer plantations. However, it has been found in mountain passes in Scotland, including well above the tree line near the top of Cairngorm, and also on Skomer Island. This suggests that it is highly mobile and can occur well away from potential breeding sites.
First detected in north west Scotland in 1991 (Stubbs, 1994), it has spread rapidly throughout the west of Britain. There are recent records from Dorset and Sussex (Edwards, 2004), so it now appears to be moving eastwards. It is therefore a species that needs to be borne in mind when recording from conifer woodlands throughout Britain.
Status & conservation:
This species is rapidly expanding in both range and frequency. It is often extremely abundant where it occurs and can be the most abundant hoverfly in some western localities.