UC Master Gardeners, Santa Clara County, CA
University of California
UC Master Gardeners, Santa Clara County, CA

Monthly Tip

Tomato Hornworm

Tip description
Both tomato hornworms and tobacco hornworms can do significant damage to tomato plants. They can eat entire leaves and take bites out of the fruit. Although they are large with a striking appearance, they camouflage themselves well on plants and can be surprisingly hard to find. Once you see one, you’ll wonder how you missed it. The first clue to their presence is often a pile of frass (insect larva excrement) on the leaves or ground under the pest. They are up to four inches long so they are easy to handpick for disposal. If you see a row of white eggs on their backs, those are from a parasitic wasp that will take care of the problem naturally. They are striking, with white striping and little round circles. The caterpillars get their name from the horn on their back end, and they are the larval stages of rather large brown moths.
 
More information: Tomato Hornworms
 
Months applicable
  • June
  • July
  • August
Category
  • 3. Pests and Diseases

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