Wing length 3 - 5mm. A very small, dark species with several similar species in its genus. N. tenur has clear wings, with no clouded veins, and all dark femora, with no yellow tip. The abdomen may have a pale, yellowish band, but this may also be absent.
Beside standing water with emergent vegetation in marshes and fens. Often associated with reeds or Typha.
Status and distribution
Widespread and common throughout Britain with a southerly bias. Common on the reserve.
Best time to see
April to November.