Trichoptera

1
Trichoptera

• Common Net-Spinning Caddisflies
  Vs. Regular
  Caddisflies

2
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.

3
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.

4
Trichoptera

• 3 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.

5
Trichoptera

• Case makers Make portable cases for protection
  and refuge. Cases can be made from
  sediment(sand, pebbles), organic matter(twigs,
  leaves) or shells.

6
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.

7
Trichoptera

• Common 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.

8
Trichoptera

• Common 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.

9
Trichoptera

• Common 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

10
Trichoptera

• Comparison of images from the key
• Case maker

11
Trichoptera

• Comparison of images from the key
• Free living

12
Trichoptera

• Comparison of images from the key
• Common net spinner