Axehead caddis (Oxyethira)

Taxonomic group

Hydroptilidae: Oxyethira

Diagnostic features

Oxyethira caddis larvae construct small, transparent, mobile cases shaped like an axe-head (hence the common name “axe-head caddis”). Each of the three thoracic segments has a hard (“sclerotised”) covering.

[Oxyethira]. Image: Stephen Moore Image — Oxyethira. Image: Stephen Moore

[Oxyethira] pupa. Image: Stephen Moore Image — Oxyethira pupa. Image: Stephen Moore

Typical habitats

Oxyethira larvae are most common in streams with limited shade, particularly at sites with abundant stream bed algae.

Feeding

They feed on filamentous algae.

Indicator value

Hard bottom: 2
Soft bottom: 1.2

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

Abundances of Oxyethira larvae are usually recorded at sites with abundant streambed algae. Such algae is likely to be the result of nutrient enrichment, limited shade and a lack of recent high flow (algae scouring) events. They have low tolerance values of 2 (hard bottom sites) and 1.2 (soft bottom sites).