Smooth cased caddis (Beraeoptera)

Taxonomic group

Conoesucidae: Beraeoptera

Diagnostic features

Beraeoptera caddis larvae construct a mobile case that is largely or entirely uncovered by sand grains. The aperture (opening) is strongly oblique and widens laterally (unlike the other smooth cased caddisflies Olinga and Confluens).

[Beraeoptera]. Aperture of case oblique. Image: Stephen Moore Image — Beraeoptera. Aperture of case oblique. Image: Stephen Moore

[Beraeoptera]. Aperture of case widens laterally. Image: Stephen Moore Image — Beraeoptera. Aperture of case widens laterally. Image: Stephen Moore

Typical habitats

Beraeoptera larvae are most common in stony, bush-covered streams.

Feeding

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

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

An abundance of Beraeoptera larvae indicates good habitat and water quality conditions, especially if mayfly or stonefly groups are also abundant. They have tolerance values of 8 (hard bottom sites) and 7 (soft bottom sites).