Caddis / Sedge
Nymphs are in the water all year, long before and after the hatch window — the season and temperature figures on this card describe when the adults emerge, not when this stage is available. It very nearly always is.
It anchors itself in fast water and spins a net to strain food from the current, so it stays put and trout rarely meet one by chance. Then the river rises. A spate tears larvae off the stones in numbers and the whole population goes down the drift at once — which is why a caddis larva is such a reliable answer in the first clearing water after rain.
- New ZealandPresent
A net-spinning caddisfly (family Hydropsychidae) endemic to New Zealand, described in the New Zealand entomological literature and by NIWA's own Trichoptera checklist as Aoteapsyche colonica — iNaturalist's current taxonomy files the New Zealand Aoteapsyche species group under Hydropsyche. The subject of published life-history and production studies on New Zealand rivers, where the larva spins a fixed silk capture net across the current to filter-feed.