Caddisflies, Pacific Northwest
Caddisflies are an important component of the aquatic insect community. The larvae live in water especially flowing streams and the larvae look much like a caterpillar with few hairs. Adults are alive for only a day or two, do not feed and are attracted to lights at night. The adults look like small moths with long antennae and most of them are drab brown or gray.
Did you ever look down into a pond and see a bundle of sticks moving about? This is the house of a small caddisfly larva. The sticks which make up the material of the caddisfly larva’s house are glued together with strands of silk. This silk comes out of an opening in the lower lip of the animal. At first it is soft and sticky, like glue, but it soon hardens. The inside of the caddisfly larva’s house is smooth, because it is lined with this silk.
The caddisfly larvae has a pair of tiny hooks at the end of his body. With these he fastens himself firmly inside his case. While he is inside his house, the larva is fairly safe. But if he is hungry, or wants to move about, he must put out his head and his three pairs of legs. When an enemy comes near, the larva will quickly disappears back into his house.
The caddisfly larvae is usually hungry and tiny plants or animals are his food. Some of these are too small for us to see without a microscope, but there are many of them living in the water. Some caddisfly larvae even eat their neighbors or even other caddisfly larvae. They absolutely amazing to observe in the wild as they swim about in their homes made of sticks.