What’s munching my native thimbleberry?

Asked October 14, 2020, 11:56 AM EDT

Since installing a thimbleberry, I’ve noticed damage to the plant that looks like some kind of pest. Little holes as well as larger chunks missing from the leaves. I also observed little black pellets on the underside of a leaf. What’s the culprit and how can I deter it? I participate in the Backyard Habitat Certification program and avoid the use of chemical pesticides. Thanks!

Clackamas County Oregon

1 Response

The holes in your thimbleberry look like they were caused by a caterpillar of some kind. The black pellets look like caterpillar frass (manure). The holes were created a while ago - the edges are brown and dried. The caterpillars are gone.

If you see fresh holes in leaves, look for caterpillars on or under the other leaves of the plant. Caterpillars can be picked off the leaves and squashed or stomped on, or dropped into a container of soapy water. Just remember that caterpillars can be the larval form of butterflies. If the damage they create is not affecting the plant, you can let some of them develop. If they're causing real problems, get a picture and we can help you identify it.