Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Guide to New Zealand's freshwater invertebrates

Spiral cased caddis ( Helicopsychidae : Helicopsyche )

Diagnostic features

Helicopsyche caddis larvae construct a small mobile case made of sand grains arranged in a spiral. At first glance they might be mistaken for small snails, but the legs of the caddis larva can be seen when the larva moves.

Typical habitats

Helicopsyche larvae are common in many stony or gravelly, bush-covered streams.


They are “collector-gatherers”, feeding on a range of organic matter accumulating on stream beds.

Indicator value

An abundance of Helicopsyche larvae indicates good habitat and water quality conditions, especially if mayfly or stonefly groups are also abundant. They have high tolerance values of 10 (hard bottom sites) and 8.6 (soft bottom sites).