Wood gnat (Anisopodidae)

Taxonomic group

Family: Anisopodidae

Diagnostic features

Anisopodid flies (also known as “wood gnats”) have larvae that superficially resemble ceratopogonid or chironomid larvae, but they have a 5-lobed tail structure resembling the spiracular disc of tipulid cranefly larvae. The head is non-retractile (unlike tipulids), there are no thoracic or abdominal prolegs (unlike chironomids), and there is no rosette of hairs at the tip of the tail (unlike ceratopogonids).

Wood gnat (Anisopodidae) larva. Non-retractile head. Image: Stephen Moore Image — Wood gnat (Anisopodidae) larva. Non-retractile head. Image: Stephen Moore

Wood gnat (Anisopodidae) larva. Tail with 5 lobes. Image: Stephen Moore Image — Wood gnat (Anisopodidae) larva. Tail with 5 lobes. Image: Stephen Moore

Typical habitats

Anisopodid larvae are occasionally found in stream samples, but it is thought they normally live above the water level amongst damp decaying vegetation.

Feeding

Anisopodid larvae feed on decaying vegetation.

Indicator value

Although Anisopodid larvae can be common in some stream samples, they are not strictly aquatic and have not been assigned tolerance values.