Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Guide to New Zealand's freshwater invertebrates

Axehead caddis ( 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.

Typical habitats

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


They feed on filamentous algae.

Indicator value

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).