Cheilosia longula (Zetterstedt, 1838)
Biology & ecology:
The larva develops in the fruiting bodies of large fungi including Boletus, Suillus and Leccinum. With 50+ larvae per fungus, the fruiting body loses shape and forms a deliquescent mass on the ground. Adults are usually found along woodland (deciduous and coniferous) edges and rides, or in glades where they can often be found on sun-lit vegetation. A range of flowers including white umbels and yellow composites are visited.
This species is widely distributed throughout Britain. It mainly occurs in acidic, sandy locations, especially heathland and moorlands. There are comparatively few records from well-recorded parts of the English Midlands, which are generally less acidic and support richer soils.
Status & conservation:
There has been a very significant decline in occurrence from most parts of Britain over the past 25 years, but occurrence in the uplands appears to be increasing. These changes may to be an artefact of recorder effort because relatively few modern recorders report the Cheilosini and there has also been a lot of effort put into some upland areas in recent years: the data may be skewed as a result. Recorded from 191 hectads since 1985.