Pest Profiles - Invertebrates

Tomato Hornworm

• About

  

  Photo: UC ANR

  Often the largest caterpillars seen in vegetable gardens – up to four inches long. Horn or thorn at rear end. Adult moths have wingspan up to five inches.

• Category

  Insect
• Signs/Symptoms

  Hornworms feed on blossoms, leaves, and fruit. At high populations they can extensively defoliate plants and scar the fruit. Striping pattern makes them hard to spot despite their size. Large, black, or green droppings on the ground beneath tomato plants usually indicate the presence of hornworms. 

• Where

  Hornworms feed on blossoms, leaves, and fruit. Entire leaves and small stems may be consumed. Large pieces from green fruit may also be chewed.

• When

  Damage by hornworm larvae is usually most common in midsummer, but there may also be a small population peak of larvae in the late summer.

• Prevent

  Rototilling after harvest destroys pupae in soil and prevents adults from developing.

• Manage

  Handpick or snip hornworms with shears. Natural enemies normally keep populations under control. 

• More Information

  Learn more about tomato hornworms.