“I found this guy in Lloydminster, Saskatchewan, Canada. What can I feed him?” writes this reader about the stick-like worm pictured below. At first, we did not see what our reader was referring to. We thought it was just one long branch. But then we noticed that the twig-like object on the right did not exactly match the rest of the branch, and does look like a separate entity. We think this is a stick caterpillar, which is a larva of the peppered moth. They are not the same things as stick insects, which are not worms or larvae of any kind, but a completely different species.

To answer our reader’s question, she will not have to feed this caterpillar, as it has plenty of food right where it is. Stick caterpillars munch on the leaves of the trees they imitate, so our reader is good to just leave this guy on the branch she found it on. Of course, if our reader found this branch far away from a tree, she could place it near a tree so that the caterpillar will find more food once it is done munching on the leaves of this branch. Now, the reason these caterpillars look the way they do is to blend in with their surroundings and camouflage against predators. And they do this exceptionally well.

What is most interesting about this is that the caterpillar is not naturally twig-colored. In fact, they can change the color of their skin to match the specific branch they are hiding on, much like a chameleon can change the color of its skin at will. On top of this, stick caterpillars will — when threatened — change their posture to better mimic a stick. Their legs will also look like the knobs on a twig, which they can use to their advantage. With all of that said, the adult peppered moth cannot change its coloration and does not change its posture, but it does naturally develop a coloration and pattern on its wings that lets it blend in in certain environments. Some are white with black speckles, and they can blend in with the lichen that grows on branches, while some are black/dark gray with white speckles, which lets them camouflage against rocks. They are really quite incredible products of evolution!

In conclusion, our reader has indeed found a stick caterpillar (AKA a peppered moth caterpillar), but she does not need to feed it. If it is far away from trees, she is welcome to move the branch and caterpillar to some trees to provide it with better food, but she does not need to worry about hand-feeding it. The caterpillar will survive just fine on its own in the wild. We hope this helps, and we wish our reader the very best!

Summary

Article Name

Twig-like Worm on Branch is a Stick Caterpillar

Description

"I found this guy in Lloydminster, Saskatchewan, Canada. What can I feed him?" writes this reader about the stick-like worm pictured below. At first, we did not see what our reader was referring to. We thought it was just one long branch. But then we noticed that the twig-like object on the right did not exactly match the rest of the branch, and does look like a separate entity. We think this is a stick caterpillar, which is a larva of the peppered moth. They are not the same things as stick insects, which are not worms or larvae of any kind, but a completely different species.

Author

Worm Researcher Anton