webworms in spring?

Asked June 7, 2019, 7:00 PM EDT

I noticed bags of webbing, with tons of little worms/caterpillars, over the ends of the branches of the mullberry trees in my yard. Poking around the internet, I am inclined to say they are webworms, but all the sites seem to say they are only active in the fall. Have you heard of webworms being active in the spring? I don't care about the mullberry, but there is a small willow nearby that I don't want to get damages - are they likely to spread? Thanks so much!

Baltimore Maryland

3 Responses

Here is our webpage all about "fall" webworm: https://extension.umd.edu/hgic/topics/fall-webworm-trees

As you'll read, there are two generations a year. The spring one is usually small, but this year it is larger than normal (weather conditions cause a lot of population swings in insects.)

These caterpillars are valuable because they feed many birds and rarely damage a tree. Unless you see webs in the willow, you don't need to do anything. If so, simply pull them out with gloved hands or break them up and let the birds take over.


Thank you!