Cheilosia impressa Loew, 1840
Biology & ecology:
The larva of this species remains unknown. Adults are found in damp situations such as carr woodland and wooded river-banks, where they visit white umbellifers, especially Hemlock Water Dropwort Oenanthe crocata, and a range of other flowers including yellow composites and buttercups Ranunculus sp. Males hover at moderate height in sheltered situations in clearings and glades.
Current records suggest that this species is mainly confined to England and Wales with the highest density of records in southern England. It occurs in a few lowland coastal localities in Scotland and one inland location in Perthshire.
Status & conservation:
Occurrence has been stable over the past 35 years with some evidence of increase since 2000. This is noteworthy because the Cheilosini tend to be under-recorded by modern recorders.
533,There has been a significant decline in occurrence since 1990. This decline may to be an artefact of recorder effort because relatively few modern recorders report the Cheilosini and the data may be skewed as a result.
537,There has been a very significant decline in occurrence from most parts of Britain over the past 25 years