Skeletonized leaves, round black debris and damaged tomatoes – sure signs of tomato hornworm damage. The hornworm is a larval form of a stout bodied, strong flying hawk or sphinx moth. The moth has a long probiscus to feed on deep-throated flowers and, in the process, is an important night time pollinator.
Damage done to tomato plants is by the caterpillar or larva. The caterpillar is green with distinctive eye spots on the side. In Jackson County they hatch in the spring after overwintering in the soil. The small green caterpillars grow and change rapidly, consuming tomato plants in addition to other members of the Solanaceae family. For the average home gardener, uncontrolled tomato plant damage may lead to an incomplete crop as the damaged plant tries to survive defoliation.
The best way to control the caterpillar is by practicing a combination of monitoring and removal. Check tomato plants every few days for signs of damage. During the warmer months the pest grows very quickly into a master of deception, hiding underneath stems and leaves. If the pest is found, hand pick and immediately destroy. While doing garden observations I always take a container of soapy water for disposal of unwanted insects. Some may prefer to crush or destroy in another way but either way, the earlier you find the caterpillar, the less damage it can do.