Chalcosyrphus nemorum

Chalcosyrphus nemorum , the Dusky-banded Leafwalker, is a common species of syrphid fly with a Palearctic and Nearctic distribution. Hoverflies get their names from the ability to remain nearly motionless while in flight. The adults are also known as flower flies for they are commonly found around and on flowers, from which they get both energy-giving nectar and protein-rich pollen. Larvae have been found under the bark of Larix, Pinus and a variety of hardwoods.

Description

For terms see Morphology of Diptera
Wing length 6.5-8.25 mm.
Hind femora are swollen and deep. Hind tibiae strongly curved and the ventral surface with
closely-set short black hairs for the whole length. The abdomen is short tergites 2-4 with a pair of pink or orange-brown marks. The legs are black with yellow knees and yellow tarsi.
The larva is figured by Hartley.

Distribution

Fennoscandia South to the Pyrenees and from Ireland East through Northern, Central and Southern Europe across the Palearctic into Russia and the Russian Far East and Sakhalin and Japan. In the Nearctic from Alaska to Nova Scotia and South to California.

Biology

The habitat is forest wetland. Adults frequent sunlit foliage of bushes on trunks of fallen trees beside water and settle on damp mud at the water's edge. Flowers visited include white umbellifers, Caltha, Anemone nemorosa, Euphorbia amygdaloides, Ranunculus, Rubus idaeus, Potentilla erecta, Sorbus aucupariaand Taraxacum. Flies from the beginning of May to the end of September.