The warm summer temperatures introduce a new kind of pest to the garden. The Tomato Hornworm starts to show itself mid- to late-summer and for 3 to 4 weeks they feed on your tomato, eggplant and pepper plants. The fruit eventually drops off the plant and burrows itself into the soil to pupate and become a Sphinx moth. To save your summer harvests this year, keep an eye out for these problem pests!
Signs you might have tomato hornworms:
- Yellowish, white eggs on the under sides of leaves
- Chewed leaves or fruit, stripped stems
- Visible black droppings on or around the plant
- Brown cocoon found in the soil around the plants
During the early summer months, it’s a good idea to start watching out for the eggs on top and under leaves. Finding the full-grown caterpillars will be a little trickier because they camouflage their body against tomato leaves. During the early morning, late dusk time you can find the caterpillars on the outer part of the plants, midday the caterpillars find shade among the inner part of the plant. Once found they can easily be picked off and disposed of.
If you find a hornworm that has white eggs attached to its body, leave it! The parasitic wasp has laid its eggs, feeding off the caterpillar paralyzing and eventually killing the caterpillar. The hatching of the beneficial wasp is great news for the gardener, but bad news for the caterpillar.
If you’re still seeing tomato hornworm damage consider using an insecticide that contains bacillus thuringiensis. Bt is a natural bacterium that is safe for humans but not so safe for the caterpillars. Avoid using harmful pesticides. These can kill the beneficial insects that prey on the hornworm such as the lady bug, green lace wing and parasitic wasp.
