Parasyrphus nigritarsis (Zetterstedt, 1843)
Syrphus nigritarsis Zetterstedt in Coe (1953).
Biology & ecology:
The larva is predaceous upon the larvae of Chrysomelid beetles on Alder Alnus glutinosa (Chrysomela aenea) sallows Salix sp. (Lochmaea capraea) and Dock Rumex (Gastrophysa viridula). Adults visit umbellifer flowers and may also be found sun-basking on leaves and generally occur in the vicinity of sallows and Alder.
This is mainly a northern and western species that is widely distributed across Scotland, Cumbria and Wales, but is also reported from East Anglia, South Hampshire and Cornwall.
Status & conservation:
Our knowledge of this species has vastly increased over the past 25 years, and it is now much more widely recorded. Too few records to detect a trend.