Brown appx. 1″ long with yellow mass on back (Mississippi)
Your inchworm has been parasitized by a small wasp. The parasites are the larval stage of Euplectrus, a chalcid wasp parasitoid.
This genus of chalcid wasp lays eggs on butterfly and moth caterpillars.
This chalcid wasp is very small. It is mostly black with tan to yellowish spot on it’s abdomen as well as has lighter colored legs and antennae.
The larvae are usually found in clusters like you see on the parasitized caterpillar. If the clusters or bumps you see are fuzzy, then the larva has pupated into a cocoon.
We talk about good bugs and bad bugs in the garden. The wasp is a good bug since it will lay eggs on many pest species of caterpillars, which will stop the caterpillar from feeding, which reduces damage to our garden crops. As the larvae from the wasp emerge, and feed on the caterpillar it will die…keeping the caterpillar from maturing. These caterpillars should be left alone, so the wasps can emerge and do their thing.
This inchworm may not be a pest species but these wasps do keep the populations of many caterpillars in check. Balance of nature.
Interesting find! Thanks for sharing with everyone!
This wasp does not sting.