Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Guide to New Zealand's freshwater invertebrates

Net-building caddis ( Hydropsychidae : Diplectrona )

Diagnostic features

Hydropsychid caddis larvae have hardened (sclerotised) plates on each of the 3 thoracic segments, and gill tufts under the abdomen. Diplectrona caddis larvae have a more “hairy” appearance than the related Aoteapsyche, and they have 7 sets of abdominal like gills (like Aoteapsyche). In Diplectrona the foreleg trochantin (segment at the base of the leg) has a spine that is not forked, unlike Aoteapsyche.

Typical habitats

Diplectrona larvae are mostly found in bush covered streams in the lower North Island and the South Island.


They construct filter-feeding nets attached to the streambed to trap drifting particulate food items.

Indicator value

Diplectrona larvae are most likely to be found in streams with good water quality. They have a tolerance value of 9 for hard bottom sites (there is no soft bottom tolerance value).