Cheilosia sahlbergi (Becker, 1894)
Biology & ecology:
The larva appears to be associated with Alpine Bistort Polygonum viviparum, where it may graze roots externally. Adults occur at high altitude (700m upwards) and have been recorded visiting the flowers of Potentilla erecta and Saxifraga spp. usually near water. They fly low and rapidly over the vegetation often perching on sun-lit stones and rocks in sheltered spots.
Restricted to mountainous areas of northern Scotland especially parts of the Cairngorms and Perthshire. Species distribution modelling suggests that this is one of the species most vulnerable to climate change.
Status & conservation:
Recorded from 10 hectads since 1985.