Sandfly or black fly (Austrosimulium)

Taxonomic group

Simuliidae: Austrosimulium

Diagnostic features

Austrosimulium is a member of the simuliid blackfly (commonly called “sandfly”) family. They have small larvae characterised by a bulbous abdomen and a head bearing filter-feeding fans. The larvae use small hooks at the end of the abdomen to attach to submerged surfaces, while the filter-feeding fans are extended to face the current.

Sandfly ([Austrosimulium]) larva. Bulbous abdomen. Image: Stephen Moore Image — Sandfly (Austrosimulium) larva. Bulbous abdomen. Image: Stephen Moore

Sandfly ([Austrosimulium]) larva. Head with filter feeding fan. Image: Stephen Moore Image — Sandfly (Austrosimulium) larva. Head with filter feeding fan. Image: Stephen Moore

Typical habitats

Austrosimulium larvae are found in fast and slow flowing, hard bottom and soft bottom streams in bush covered, farmland and urban areas.

Feeding

Austrosimulium larvae are filter feeders using their fan of setae to collect drifting fine particulate organic matter.

Indicator value

Hard bottom: 3
Soft bottom: 3.9

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

Austrosimulium larvae can be abundant in pristine streams, but also in poor quality urban streams. They have low tolerance values of 3 (hard bottom sites) and 3.9 (soft bottom sites).