Trichoptera

Common Net-Spinning Caddisflies

Vs.

Regular Caddisflies

Trichoptera North of the Rio Grande there are ~1350 species

represented in 147 genera, 22 families.

Habitat can range from slow moving lake waters to very fast rivers and streams with almost all habitats in those environments being populated.

Four main feeding types: Shredders – Feed on living and/or decomposing plant matter. Collectors – Filter debris or gather nearby fine organic

particulates. Scrapers – Feed on periphyton and/or fine organic particles. Predators – Feed on whole animals or large parts.

Trichoptera Basic morphology – Head, Thorax (3 segments),

Abdomen (9 segments, the anal prolegs are interpreted as derivatives of the tenth segment).

Tolerance – (0-10) Ranges from 0.56-8.1. Tolerant ≥ 7. Not very many tolerant genera.

Trichoptera3 different types (based on case types).

Case maker - makes a case from organic debris or sediment. Can be fixed or portable (Most families).

Fixed retreat-makes cases or nets that are attached to a substrate of some type.

Free roaming – have no fixed retreat or portable case.

Trichoptera Case makers – Make portable cases for protection and

refuge. Cases can be made from sediment(sand, pebbles), organic matter(twigs, leaves) or shells.

Trichoptera Net Spinners – Three main families:

Polycentropodidae – 76 species in 7 genera, usually found on the bottom and prefer slower waters.

Philopotamidae – 42 species in 3 genera, attach nets to underside of rocks in areas with good flow.

Hydropsychidae – 144 species in 12 genera, found in fast flowing areas on top of rocks.

TrichopteraCommon net spinners – Hydropsychidae

Dorsal plates (sclerites) on all three thoracic segments. Branched gills on the ventral surface of the last two thoracic

segments and most of the abdominal segments. Usual have a setal tuft at the end of each anal proleg.

TrichopteraCommon net spinners – Hydropsychidae (cont.) One other family might be confused with these: Hydroptilidae –

also known as micro-caddisflies. 2-6mm in length. Three dorsal thoracic plates. No gills on adbomen or thorax. Case maker.

TrichopteraCommon net spinners – Hydropsychidae

Recap:Have three dorsal plates (sclerites)on the thorax.Have gills on the ventral side of the second and third thoracic

segments and most of the abdominal segments.

(first instars may not have gills)Usually have a tuft of setae on each anal proleg.Might be confused with Hydroptilidae

TrichopteraComparison of images from the key

Case maker

TrichopteraComparison of images from the key

Free living

TrichopteraComparison of images from the key

Common net spinner