Caddis Fly Life Cycle

I never understood why most fly fishermen overlook caddis flies. Caddis flies are often more abundant then mayflies and tend to hatch over a longer period of time. Trout feed heavily on them and will often target caddis flies over mayflies. Here is a look at the life cycle of a caddis fly for fishermen.

After hatching from eggs caddis flies develop into a small wormlike insect that lives below the surface of the water. Most caddis flies in this stage build some type of casing to protect their soft bodies from predators. They may use small rocks, plant debris and some even make there casing out of sand. Like all animals there are exceptions, there are a few species of caddis that don't make any type of casing to protect themselves. Most caddis species live under the surface of the water for around a year before they hatch into adults.

Caddis flies have a very unique strategy for hatching into adults. First, caddis flies form a gas bubble that shoots them to the surface very quickly. Next a caddis fly moves vigorously to shed its "shuck" (pupae skin) to emerge as an adult. Then they will often bounce or skip across the water in attempts to take flight. All of this action they perform often brings furious feeding behavior from trout. Since the caddis are normally on the move the trout need to attack them quickly to ensure a meal. This is good news for fly fishermen, but I continue with that later.

After caddis flies have hatched into adults they will return to the water usually in a day or two to lay their eggs. Huge swarms of caddis flies will fly above the water to lay their eggs. Some caddis simply land on the water and deposit their eggs in the water, while others actively swim or crawl under the waters surface to deposit their eggs. However, after they have mated and laid their eggs all caddis flies will die. This can create a feeding frenzy for trout, as all they have to do is such in the dead insects as they float down the river.

Caddis flies come in many different colors and sizes and hatch from early spring through late fall. The most common colors of caddis are black, tan, and green. There are many patterns available to fly fishermen to represent all the life stages of a caddis fly. These patterns can be fished dead drifted, on a swing or twitched, because caddis may be skipping across the water or floating quietly all presentations can be effective.