An Introduction to Caddis
Among the most prolific orders of Montana insects, caddis are essential to a trout's diet in the hallowed Montana fly fishing rivers near Bozeman.
Caddis are among the most prolific Montana insect species that our Montana fishing guides use during our guided fly fishing trips.
Hatches seem to jump out of Montana rivers from spring through fall. A nocturnal species, caddis (Trichoptera) are attracted by light, so anglers will see them many evenings from late-April through October.
Characteristics of Caddis
- Wings lay along their backs like a tent when at rest, and they flit through the air in great numbers, at times.
- Two antenna point forward on adults.
- Pupa rapidly ascend through the water column, eliciting aggressive subsurface strikes from feeding trout.
- Thick, swarming clouds of caddis over bankside vegetation is commonplace near dusk along Montana rivers throughout the state in the summertime.
Overview of the Caddis Lifecycle
- Caddisflies (as they are sometimes called) undergo a complete metamorphosis (egg, larva, pupa, adult).
- Eggs are laid in or near water in a jelly-like substance and stay there for 1-3 weeks.
- Larva breathe using gills and come in bright green, brown, and dark olive colors. The larval stage lasts 9-10 months. In the larval stage, caddis eat all types of food including plants and other insects.
- A distinguishable characteristic of many species is the construction of various structures for protection and camouflage around their larval bodies. Using a saliva-like substance, they “glue” together pebbles or sticks and adhere themselves to river rocks. Some species, however, are free-living and live near the bottom of the waterway.
- All species create a case during pupation (similar to a caterpillar turning into a butterfly), and during this stage that lasts from 2-5 weeks, caddis develop a strong pair of mandibles to bite away its shelter to rise to the surface. From there, legs help them crawl out of the water to then emerge and fly.
- As adults, they’ll time their hatch to happen together over about a 3-week period on a given stretch of stream. Adults are observed in brown, tan, and even black colors throughout legendary Montana flyfishing rivers.
Top 10 Caddis Fly Patterns for Fly Fishing in Montana
