Free-living caddis (Hydrochorema)

Taxonomic group

Hydrobiosidae: Hydrochorema

Diagnostic features

The New Zealand hydrobiosid caddis larvae have pincers on their forelegs. Hydrochorema larvae have a long white body and smallish orange or red head. The prosternal plate (shield-like plate between the forelegs) is relatively square and appears to have broken edges along the sides.

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

[Hydrochorema]. Prosternal plate with “broken” edges. Image: Stephen Moore Image — Hydrochorema. Prosternal plate with “broken” edges. Image: Stephen Moore

Typical habitats

Hydrochorema larvae are common in stony streams and rivers, in bush covered and farmland areas.

Feeding

They are predators, feeding on other stream invertebrates.

Indicator value

Hard bottom: 9
Soft bottom: unassigned

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

The presence of Hydrochorema larvae indicates good water quality, particularly where a range of mayfly and stonefly nymphs are also present. They have a tolerance value of 9 for hard bottom sites (there is no soft bottom tolerance value).