We heard from a reader who has a “worm” problem with her mimosa trees. She explained there are some sort of “worms” coming down from the branches. She thinks they might be inchworms or silkworms, and they are a complete nuisance. She wants to get rid of them immediately.

First, we believe that she is dealing with caterpillars, not worms. Even inchworms and silkworms, although they both have the word worm in their title, are technically caterpillars. Caterpillars are the larvae of moths and butterflies. We agree with our reader, the pests could be inchworms or silkworms, or they could be mimosa webworms. Although we don’t have a picture, we believe her tree is probably filled with mimosa webworms. Getting rid of caterpillars on trees generally involves the same steps no matter the species of caterpillar.

Caterpillars can be considered pests because they defoliate trees in record time, however the damage they cause is mostly cosmetic. Most trees can handle the defoliation and recover between seasons. Mimosa webworms in particular can be especially unsightly since they spin down from the branches on a strand of silk when it is time for them to pupate (a stage in their life cycle before they mature into moths). To get rid of these pests, she can begin by knocking down the hanging silk strands with a rake or broom, and disposing of what falls from the tree. She can also wrap a foot of the tree trunk in a sticky substance (perhaps duct tape with the tape side facing out). This will hinder caterpillars from accessing the tree in the first place. There are also insects that eat webworms, like wasps. She can introduce these natural predators by purchasing the insects directly, or by planting things that attract wasps, like sunflowers. Finally, there are also some chemical sprays that some readers utilize to get rid of caterpillars. We don’t promote the use of chemicals, but if our reader is interested in exploring this option, she can visit a local Home & Gardening store.

To wrap up, one of our readers is stressed out because her mimosa trees are filled with webworms. We listed some ways to get rid of these caterpillars, and informed our reader that although they are annoying, the damage mimosa webworms inflict is superficial.