Dixid midge (Nothodixa)

Taxonomic group

Dixidae: Nothodixa

Diagnostic features

Nothodixa is a member of the dixid midge family. The dixids have small, worm-like larvae that are often bent into a U-shape when live. There are flat, hair-fringed lobes on the last abdominal segment, and the head is often tipped backwards. In Nothodixa there are distinct oval arrangements of fine black hairs on the abdomen.

[Nothodixa]. Flat, hair-fringed lobes. Image: Stephen Moore Image — Nothodixa. Flat, hair-fringed lobes. Image: Stephen Moore

[Nothodixa]. Oval arrangement of black hairs on abdomen. Image: Stephen Moore Image — Nothodixa. Oval arrangement of black hairs on abdomen. Image: Stephen Moore

Typical habitats

Nothodixa larvae are found just under the water surface along the margins of small streams.

Feeding

Dixids use brush like mouthparts to capture drifting food such as algae and other micro-organisms. Nothodixa is also known to feed on organic detritus and oligochaete worms.

Indicator value

Hard bottom: 4
Soft bottom: 9.3

The tolerance values (ranging from 0 to 10) give an indication of which are the sensitive taxa (values of 8 or more) and which are the tolerant taxa (values of 3 or less). For more information see: Indicator species

Nothodixa are infrequently recorded but they tend to occur in good quality streams. They have moderate to high tolerance values of 4 (hard bottom sites) and 9.3 (soft bottom sites).