Bad News for Tomato Hornworms, Good News for Us

Screen Shot 2018-08-24 at 7.30.40 AMWhat are those white ovals on this tomato hornworm found in the Pitney Meadows Community Gardens?

They are the pupating cocoons of braconid wasps and a welcome sight in the garden. The wasp is a beneficial parasite that lays its eggs on the hornworm.

As they grow, they feed on the hornworm. Once the wasps emerge, the hornworm dies and the wasps look for another hornworm to repeat the cycle.

It is good to see our gardens are a good habitat for the wasp, which will help us keep tomato hornworms out of the garden.

Tomato Hornworms in the Garden

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This morning, I found tomato hornworms, Manduca quinquemaculata, on a single tomato plant in one of the raised beds.

These are destructive caterpillars that will defoliate a plant very quickly and decimate your tomatoes. They also like to devour peppers, potatoes and eggplants.

Here’s what to look for: black turds, defoliation of the tender top leaves and a green caterpillar that is both fascinating and disgusting at the same same.

Usually there are many turds on a leaf or on the ground. If you see this, start looking for the hornworms, which can be up to four-inches long. They are called hornworms because they have a black “horn” on the last abdominal segment.

Handpick hornworms from infested plants and remove them from the garden.

Hornworms become a moth commonly known as a hummingbird, hawk, or sphinx moth.

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Enter a captionDamage down by Tomato Hornworms