Your Garden . . . with Kate Russell: Learn to identify 10 different types of tomato pests in the South Valley

Published in the June 14 – June 27, 2017 issue of Gilroy Life

By Kate Russell

Kate Russell

Many Gilroy gardeners get started because of tomatoes. Sweet, luscious, sun-warmed tomatoes, fresh from the vine, make store-bought varieties tasteless by comparison. To grow those delicious tomatoes, however, South Valley backyard gardeners need to be on the lookout for pests that enjoy tomatoes as much as we do. Knowing what, when and where to look for tomato pests can help you get the most out of your tomato crop.

These are the 10 worst tomato pests found in the South Valley region:

1. Hornworms — Surprisingly large green caterpillars with white chevron stripes and a distinctive hook on the tail end devour leaves, stems, and fruit; the coloration makes them difficult to see, so look for the damage they cause instead.

2. Tomato fruitworms — Medium-sized, tan to brown moths lay eggs that hatch out creamy white caterpillars, with black heads, that feed deep inside the fruit, growing into a 2-inch green, yellow, or brown caterpillar.

3. Tomato pinworms — Tiny, multi-colored larvae feed on leaves and fruit; feeding occurs just under the fruit skin, leaving behind piles of brown frass (bug poop).

4. Stinkbugs — Shield-shaped brown or green pests that leave pinpricks in green fruit; under these discolored areas, the fruit turns corky and inedible; stinkbugs are vectors for several yeast and fungal diseases.

5. Whiteflies — Tiny, white, elongated eggs are laid in small clusters; hatched larvae feed on leaves, causing curling and yellowing; fruit may ripen unevenly when infested; these pests are resistant to pesticides and can tomato yellow leaf curl disease and tomato infectious chlorosis virus.

6. Leafminers — Tiny black and yellow flies lay eggs in leaf tissue; the hatched larvae burrow between leaf layers, leaving telltale serpentine trails that indicate leaf loss, reduced plant vigor, and even plant death are possible.

7. Tomato russet mites — Too small to see without a lens, these pale green tubular mites cause stippling, leaf yellowing and curling, rough, russet-colored damage to leaves, stems, and fruit; unless it is treated with sulfur, the plant can die.

8. Thrips — Small, pale yellow, flying insects with two pairs of fringed wings, whose feeding distorts flowers and other plant parts; thrips can also carry tomato spotted wilt virus.

9. Wireworms — Slender, hard-bodied, yellow to brown larva of click beetles feeds on seeds, severs new roots and stems, and burrows into older stems and roots throughout the growing season.

10. Tomato bugs — Corky rings around stems are seen in mid-summer where feeding by small green bugs occurs, making stems brittle and likely to break; flower and fruit drop are common.

Once a tomato pest is identified, it is easier to make informed decisions about how to control it with the least amount of chemical intervention. Contact your local Master Gardeners for more information about specific tomato pest problems.

You can learn more about tomato pests at the South County Teaching and Demo Garden, found at St. Louise Hospital, 9400 No Name Uno, in Gilroy. You can learn more at www.mgsantaclara.ucanr.edu/demonstration-gardens/south-county-teaching-and-demonstration-garden/ Classes are regularly offered to the public. For more information, check www.mgsantaclara.ucanr.edu/events/ or call (408) 282-3105 between 9:30 a.m. and 12:30 p.m., Monday through Friday.

Kate Russell is a Santa Clara County Master Gardener. She wrote this column for Gilroy Life.