I found this stick walking in the water … what is it?

You might have found  these little sticks moving about in the water at a beach, pond or in a marsh. If you take a closer look at them, you will notice a tiny insect head and legs poking out from one end.

What you are looking at is a caddisfly.

Some caddisfly larvae (i.e. immatures) use materials found around them to construct tubes. Materials to make tubes can include anything from leaves, sticks, snail shells, rocks or sand. Generally, each species will construct tubes in a specific fashion. Also, some caddisflies that live in river systems will add pieces that act like keels on their tubes. These keels help the tubes to orient themselves so that their openings are always pointing upstream.

So what is the function of these tubes? One function is to help camouflage the caddisfly from predators. Another possible function is to help the caddisfly absorb oxygen from the water. Scientists have discovered that some species can create a water flow through their tube by undulating their abdomen. By flowing water through their tube, it makes it easier for the animal to absorb oxygen dissolved in the water.

After a few months in the water, the caddisfly larvae will mature into an adult that emerges from the water. Caddisfly adults look quite similar to moths, except that caddisflies have hairy wings whereas moths have scaly wings. Most caddisfly species only live 1-2 weeks as adults, spending most of their time reproducing. Both caddisfly larvae and adults are an important food source for fish, birds, and bats.

So, next time you see a stick walking around in the water, remember our incredible insect architects: the caddisflies.

If you want to see beautiful close-up pictures of caddisflies, please visit Jan Hamrsky’s website.