Wing length 6 mm. Abdomen is dark grey-brown and the thorax is dark on top but lighter at the sides. The wings lack a discal cell and the veins are hairy. The anal vein runs parallel to the hind wing margin for half of its length. Male genitalia are dark and last tergite in the female is dark.

Erioptera fusculenta looks very similar but has pale male genitalia (dark in E. fuscipennis) and in the female the last tergite is yellow (dark in E. fuscipennis).

Requires detailed examination.

Found in wet muddy open habitats, often by streams or ditches with trampled edges.

Flies May to October.

Widespread and fairly frequent in Britain.

Fairly frequent in Leicestershire and Rutland.