The ecnomid caddisfly larvae have at least some hardening (sclerotisation) on each of the 3 thoracic segments. Unlike the hydropsychids, there are no gills under the abdomen. In Ecnomina the sclerotisation of the mesothorax and metathorax is only partial and has little pigmentation, unlike in Zelandoptila where the sclerotisation is complete and more pigmented.
They are common in some bush-covered streams, particularly north of Auckland.
Ecnomina larvae are thought to be predators, feeding on other stream invertebrates.
Ecnomina larvae are most commonly found in streams with good water quality. They have relatively high tolerance values of 8 (hard bottom sites) and 9.6 (soft bottom sites).