Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Guide to New Zealand's freshwater invertebrates

Free-living caddis ( Hydrobiosidae : Hydrobiosis )

Diagnostic features

The New Zealand hydrobiosid caddis larvae have pincers on their forelegs. Several of the common hydrobiosid species belong to the genus Hydrobiosis. Depending on the species, the prosternal plate (shield-like structure between the forelegs) may be a single, roughly square plate (e.g. H. parumbripennis and H. centralis), or divided into 3 pieces (e.g. H. clavigera and H. silvicola).

Typical habitats

Hydrobiosis larvae are common in stony streams all over New Zealand, in bush-covered and farmland areas.


They are predators, feeding on other stream invertebrates.

Indicator value

Hydrobiosis larvae can be common in streams with moderate to good water quality. They have mid-range tolerance values of 5 (hard bottom sites) and 6.7 (soft bottom sites).