Stony cased caddis (Oeconesus)

Taxonomic group

Oeconesidae: Oeconesus

Diagnostic features

Oeconesus caddis larvae construct mobile cases with coarse sand grains. They have a circular head with a relatively flat top circled by a carina (sharp edge). The mesonotum (second segment behind the head) has 6 coloured (sclerotised) plates, some of which have a black front edge.

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

[Oeconesus]. Mesonotal plates, some with black edge. Image: Stephen Moore Image — Oeconesus. Mesonotal plates, some with black edge. Image: Stephen Moore

Typical habitats

Oeconesus larvae are most common in bush covered streams.

Feeding

They are collector-gatherers (feeding on fine particulate organic matter) and shredders (feeding on leaf litter).

Indicator value

Hard bottom: 9
Soft bottom: 6.4

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

An abundance of Oeconesus larvae indicates good habitat and water quality, particularly if mayfly and stonefly nymphs are also abundant. They have tolerance values of 9 (hard bottom sites) and 6.4 (soft bottom sites).