The Q&A Archives: Hornworms on Tomatoes

Question: For the past two years we have had infestations on our tomatoes of green worms, up to two inches long and as large around as your little finger. They have a single horn on their head and frequently are covered with many small white eggs on their backs. They clip off the end of branches and eat large sections of the tomatoes.

Answer: Those green worms are tomato hornworms. They are quite a shock to see on your tomato plant because they get so large and I swear you can hear them chewing the leaves if you're really quiet. Those white eggs on their backs are eggs of braconid wasps.This native wasp lays eggs on the caterpillars, and the hatchlings burrow within the pest to feed. If and when you see this phenomenon again, leave the caterpillar where it is, and the wasp larvae will take care of it for you.

The next best control of these hornworms is hand picking if you only have a few. For larger numbers, spray the organic pesticide Bt on the plants. This bacteria kills the hornworms, but will not harm the birds, bees, animals and other insects in the garden. It is very safe. Check local garden centers for Bt. It's widely available.

« Click to go to the homepage

» Ask a question of your own

Q&A Library Searching Tips

  • When singular and plural spellings differ, as in peony and peonies, try both.
  • Search terms are not case sensitive.

Today's site banner is by cocoajuno and is called "Here's looking at you."