If you see your tomato foliage rapidly disappearing, chances are you have one or more tomato hornworms. Another sign that this pest is at work is the black pepper-like “frass” (aka caterpillar poop) that is sprinkled over the tomato foliage. Look closely at the stems and underside of the leaves and you’re likely to find a large, fat tomato hornworm. These are impressive caterpillars that almost look like a Tiffany broach. They can do a lot of damage to tomato plants, however, so pick them off and either throw them into another part of the garden or squash them.
If you see a hornworm that has what appear to be grains of white rice attached, however, leave it in the garden. These are the cocoons of pupating braconid wasps. They are a form of parasite that will kill the hornworm as they develop. Leaving them in the garden means that you’ll have more of these small braconid wasps that will keep future hornworms under control. So put those parasites to work for you! The more hornworms that they kill off, the fewer you’ll have to hand pick from your tomato plants.
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