Cased caddisfly (Hudsonema)

Taxonomic group

Leptoceridae: Hudsonema

Diagnostic features

Hudsonema caddis larvae construct long, slender mobile cases made of plant fragments or sand grains. Hudsonema alienum arranges rectangular plant fragments in neat spirals along the case, and the stripy-legged Hudsonema amabile cover their case mainly in sand grains.

[Hudsonema alienum]. Image: Stephen Moore Image — Hudsonema alienum. Image: Stephen Moore

[Hudsonema amabile]. Image: Stephen Moore Image — Hudsonema amabile. Image: Stephen Moore

Typical habitats

Hudsonema larvae are common in many stony, gravelly or weedy, bush-covered or farmland streams.

Feeding

Leptoceridae include species that are shredders (eating plant matter) and predators (eating other invertebrates). The Hudsonema species may be both shredders and predators.

Indicator value

Hard bottom: 6
Soft bottom: 6.5

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 Hudsonema larvae indicates good habitat and water quality conditions, especially if mayfly or stonefly groups are also abundant. They have tolerance values of 6 (hard bottom sites) and 6.5 (soft bottom sites).