Free-living caddis (Zelandoptila)

Taxonomic group

Ecnomidae: Zelandoptila

Diagnostic features

The ecnomid caddisfly larvae have hardening (sclerotisation) on each of the 3 thoracic segments. Unlike the hydropsychids, there are no gills under the abdomen. In Zelandoptila the thoracic sclerotisation is more complete and darkly pigmented than in the related Ecnomina.

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

[Zelandoptila]. Complete sclerotisation on all three thoracic segments. Image: Stephen Moore Image — Zelandoptila. Complete sclerotisation on all three thoracic segments. Image: Stephen Moore

Typical habitats

They are most likely to be found (though usually in low abundance) in bush-covered gravelly streams.

Feeding

Zelandoptila larvae are thought to be predators, feeding on other stream invertebrates.

Indicator value

Hard bottom: 8
Soft bottom: 7

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

Zelandoptila larvae can be an indication of good water quality, particularly if they are found along with a range of mayfly and stonefly taxa. They have tolerance values of 8 (hard bottom sites) and 7 (soft bottom sites).