Fly Fishing Getting Started - The Caddisflies


Trout enjoy a wide array of food, with insects being more popular. While mayflies (Ephemeroptera) enjoy much of the spotlight, caddisflies (Trichoptera) are incredibly plentiful in waters across the region. Not always the preferred insect of fly anglers, mostly due to a lack of familiarity.

Caddisflies are hardy insects and have thrived in streams that have been decimated by pollution. Streams like the Tulpehocken, Oil Creek, and Casselman are just a few streams known for their abundant caddisfly populations in our region. For many of these streams, the caddisfly is so prolific that mayflies are often an afterthought for anglers.

The caddisfly behavior is a little less predictable and is certainly one of the reasons it is not as popular for many anglers. Many mayflies can be timed to within a few days and hours. The Green Drakes on Penn's Creek are revered by anglers the same way the "Swallows" of Capistrano are anticipated at the Mission San Juan Capistrano. Caddisflies, not so much.

That is not to say great hatches of caddisflies are not enjoyed by anglers and trout, as there can be wonderful evenings and days with them covering a stream. Just as often, there can be sporadic emergers happening without much fanfare.

There are over 1200 species of caddisflies in the country. They range in size and colors covering the gambit of black, green, tan, cream, and white bodies. The more popular Grannom hatch does arrive across much of the region at the end of April and is much anticipated by anglers and trout alike.

To get some understanding of their cycle it is as easy to do as by simply lifting a rock the next time out on the water.


Many types of caddis larvae can be found at the bottom of the stream in self-made protected cases or roaming along the bottoms of streams. Some of these species create protective cocoons made of small stones or sticks held together with silk-like threads. This thread is also used to secure the larvae to larger rocks or stream beds where they live.

As the caddisflies mature, they reach the pupa stage where they hold up inside their cases and prepare to emerge as adults above the water. This transformation from water to wing is the most dangerous for all insects. The caddisfly rises from its case, often with the help of a small gas bubble pulling it towards the surface. Once there, it emerges with its uniquely folded tent-style wings and takes flight.

The caddisflies return to lay their eggs either on the surface or by diving to the bottom, depending on the species. Like when they emerge, this is the time when they are most susceptible to hungry trout. The cycle of life then returns as these eggs transform into larvae again.

Like mayflies, caddisflies begin in earnest in April and are a big part of many streams. Continued sporadic hatches can be found through the late Fall.

To learn and discuss more mayflies on the site head over to the Hatch and Entomology Forum. Beginners can follow along and learn more in the Beginners Forum.

A great online site to follow and get deep into the Latin is Troutnut and his Aquatic Insects of our Trout Streams. A must-read!!
For further reading check out Gary LaFontaine's book Caddisflies.
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