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Pest Profiles - Invertebrates

Tomato Hornworm

  • About

    Photo: UC ANR
    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
  • 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.