What Eats Caddisflies?

Caddisflies develop in a four-stage process called complete metamorphosis. The stages are: egg, larva, pupa, and adult. In this process, the immature caddisflies live in a different place from the adults. Because of this, the adults and the immature caddisflies will be vulnerable to different predators.

Immature caddisflies are aquatic. The female caddisflies deposit their eggs in the water or on the shore. When the eggs hatch, the larvae move around in the water and find food. They live in the water and breathe with gills. Many larvae make cases that they use as shelters.

When the larvae are full grown, they stop moving around. They seal themselves in their case and change into an adult caddisfly. During the summer, this takes about two weeks. In the fall, the larvae will stay in the case through the winter and emerge in the following spring.

After changing, the caddisfly comes to the surface of the water. It sheds the pupal skin and emerges as a winged adult caddisfly. It flies into the air to find a mate and begin the life cycle again.

During the larva stage, caddisflies are food for many types of fish. In some parts of the United States, crayfish also eat caddisflies and caddisfly larvae. Some aquatic insects also eat caddisfly larvae and the pupae.

Trout like caddisflies so much that many fly fishermen study their feeding patterns. Some fishermen make lures that look like caddisflies.

After they have become adults, caddisflies become food for many types of birds. Bats, frogs, salamanders, insects, and spiders also prey on caddisflies.

Although we don't eat them, caddisflies become targets for humans when they fly to the lights of homes and businesses in large numbers. This is the only time caddisflies are pests to humans.