Skip to content

Smooth cased caddis (Confluens)

Taxonomic group

Conoesucidae: Confluens

Diagnostic features

Confluens caddis larvae construct a smooth mobile case with no covering of sand grains. The front edge of the pronotum (first segment behind the head) is fringed by long black hairs.

Typical habitats

Confluens larvae are often found amongst aquatic mosses in stony, bush-covered streams.


Their frequent occurrence amongst aquatic mosses and liverworts may be because they feed on these plants or on the organic matter trapped amongst them.

Indicator value

  • Hard bottom: 5
  • Soft bottom: 7.2

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 Confluens larvae indicates good habitat and water quality conditions, especially if mayfly or stonefly groups are also abundant. They have tolerance values of 5 (hard bottom sites) and 7.2 (soft bottom sites).