CADDISFLIES
(Trichoptera)
Caddisfly Larva
Juvenile caddisflies are called ‘larvae’. Caddisfly larvae live in both fast- and still-water. Most are ‘crawlers’ or ‘sprawlers’, living on and underneath rocks or other substrates. Species feed on a variety of food items, including algae, detritus, or other invertebrates.
Caddisfly larvae have a hardened head but a soft, grub-like abdomen with two hooks on the end.
Most caddisflies fall into one of two categories:
- Case-Making Caddis create portable houses (‘cases’) by gluing together rocks or twigs using silk produced by their salivary glands.
- Net-Spinning Caddis make tunnels and webs out of silk, which they live inside and use to catch food.
Caddisfly Pupa
The pupal stage is the transitional phase of development between the larva and adult. When the larvae are fully grown, they create a pupal chamber, much like a caterpillar. Inside, they transform over the course of days to weeks. Once mature, most pupae create a gas bubble and float to the surface of the water and emerge as an adult.
Most species pupate and emerge after only one year.
Caddisfly Adult
Caddisflies are closely related to moths, and they look somewhat similar. However, they can easily be differentiated. Caddisflies have long, skinny antennae and hold their wings tent-like over the abdomen. Like moths, they are good fliers. After mating, the females return to the water to lay their eggs by splashing and skating across the water or by diving underwater and deliberately placing their eggs on an ideal surface. Caddisflies are very diverse, and the overall appearance of adults is similar among species.
