Wing length 3 to 5 mm. This tiny species is similar to N. geniculata but in the male the third antennal segment is relatively narrow, and about one and a half times as long as broad. The female of this species has less waisted lateral margins to tergite two than in N. geniculata. The male has a yellow band on the abdomen on tergite three, whilst the female may be all black or have various spots and bars on tergites two and three.

Neoascia geniculata

Marshes and fens, especially by the edges of standing water.

April to November peaking in July.

Widespread and fairly common in Britain.

Fairly frequent in Leicestershire and Rutland.