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How to Kill Bugs on Tomato Plants

By Barbara Fahs ; Updated September 21, 2017
Tomatoes are generally fairly carefree.
Tomato plant image by Trombax from Fotolia.com

Tomato plants are generally hardy and easy to grow. However, several types of insects can attack them--the notorious tomato hornworm is the most destructive creature that you can find on your plants. You can use chemical pesticides, but consider the effect on other insects that might benefit your garden. In addition to bees, which are essential for pollination, you might kill other beneficial insects that can eat your problem insects. But simple, nontoxic remedies are inexpensive, effective and easy to use.

Pick tomato hornworms, snails and slugs by hand. Be sure to wear garden gloves. Search for hornworms during the daytime and slugs and snails at night, using a flashlight. Squash these creatures with your foot or cut them in half with clippers or scissors.

Control a severe infestation of snails and slugs by scattering iron phosphate granules or diatomaceous earth on the soil around your plants.

Blast your tomato plants with a sharp stream of water to knock off aphids and other crawling insects. Repeat this treatment every day for several days. Keep watch over your plants for signs of insect pests and repeat your water spray when necessary.

Spray your tomatoes with insecticidal soap for severe infestations of aphids and other small sucking insects. Repeat your application every other day until you see no further sign of these insects. Spray again later if a new infestation occurs.

Hang several yellow sticky traps around your tomato plants if whiteflies or fruit flies attack your tomatoes. This natural product is available at nurseries and garden supply centers.


Things You Will Need

  • Garden gloves
  • Flashlight
  • Clippers or scissors
  • Hose with spray attachment
  • Insecticidal soap
  • Iron phosphate granules
  • Diatomaceous earth
  • Bacillus thuringiensis (Bt)
  • Sticky traps


  • Hand picking hornworms, slugs and snails is an effective control method if your infestation is not severe. If these creatures remain after you have picked them off for several days in a row, consider using Bacillus thuringiensis (Bt) on your plants. This product is considered organic and is available at garden supply stores.
  • Symptoms of aphids include leaves that curl or small green or black insects, mostly on the underside of leaves.

About the Author


Barbara Fahs lives on Hawaii island, where she has created Hi'iaka's Healing Herb Garden. Fahs wrote "Super Simple Guide to Creating Hawaiian Gardens" and has been a professional writer since 1984. She contributes to "Big Island Weekly," "Ke Ola" magazine and various websites. She earned her Bachelor of Arts at University of California, Santa Barbara and her Master of Arts from San Jose State University.