Net-spinning caddisflies

Definition

A common name for the caddisfly family Hydropsychidae, referring to the filter-feeding behavior of their aquatic larvae, which spin silken capture nets across the openings of their retreats in running water. These conical or funnel-shaped nets strain drifting particulate organic matter, algae, and small invertebrates from the current. The family is among the most abundant and ecologically significant insect groups in lotic (flowing-water) ecosystems worldwide, with larvae serving as important ecosystem engineers and prey for fish.

Etymology

From the silken nets constructed by larvae; 'caddisfly' derives from Middle English 'caddis' (woolen braid or ribbon, possibly alluding to larval cases of other families).

Example

In riffle habitats of temperate streams, net-spinning caddisflies such as Hydropsyche and Cheumatopsyche larvae can reach densities exceeding 10,000 individuals per square meter, their collective filtration significantly altering seston transport and benthic food webs.

Synonyms

• hydropsychids

Related Terms

• Hydropsychidae
• filter-feeding
• rheophilic
• case-building caddisflies
• Trichoptera
• functional feeding groups
• lotic ecology

Usage Notes

The term refers specifically to Hydropsychidae and should not be applied to other Trichoptera families; some caddisflies build portable cases, others are free-living predators, and a few spin simple retreats without capture nets. Specialists typically use 'hydropsychids' for brevity in technical writing.