caterpillar covered with white things

Asked July 22, 2019, 12:02 PM EDT

We found this caterpillar on one of our tomato plants. Can you tell us what the white things are? Thank you.

Anne Arundel County Maryland

1 Response

Hi- you are witnessing natural control of an insect pest (hornworm) by a tiny parasitic wasp. The white things are cocoons that the wasp larvae have spun after feeding inside the hornworm. A small adult wasp will cut a hole in the top and emerge. Always leave these parasitized hornworms alone so the wasp can continue its lifecycle. A large percentage of hornworms are controlled this way.
https://extension.umd.edu/hgic/topics/braconids-ichneumonoid-wasps
Jon