What is this Caterpillar ?

Asked August 18, 2015, 2:20 AM EDT

This seems to be eating my oak leaves - whole branches with stems and not leaves. Next to a naturalized area with other trees. Don't see any cocoons. I've looked through google images but was not able to find anything that matches this. Would like to know what this is and what you recommend. Thank you,

Howard County Maryland

1 Response

This looks like the orange striped oakworm. This is a late season pest that feeds on oak and other tree species.
Mature larvae are about 1 1/2 inches long. They are black with eight orange stripes and two black spines behind the head. Look for clusters of caterpillars feeding near defoliated areas. Jar the branches and some may drop to the ground making collection and identification easier. The caterpillars feed in clumps on the ends of branches. Older caterpillars are defoliators. When populations are small defoliation usually occurs one branch at a time.
You can prune out branches or knock them down with a pole pruner to make collections easier. Drop into a bucket or soapy water. It is late in the season and usually by this time of year the trees have stored enough energy to be able to take the defoliation in stride. There is an ichneumonid wasp that parasitizes this caterpillar. mh