Tomato hornworms are the larval stage of the Sphinx moth and are the largest caterpillars found in Alabama measuring up to 4 inches in length. They are green in color and have eight V-shaped white and black marks on each side of their body making them difficult to see because of this protective coloring. One of the last abdominal segments on the caterpillar has a spine-like blue-black horn that that gives this insect its' name. They primarily damage tomato plants but can also attack eggplant, pepper, and potato. As they feed they leave behind large, black droppings (frass) that accumulate on the ground beneath the affected plants. The sizes of these garden pests allow them to quickly defoliate targeted plants. Occasionally, they may also feed on green fruit. Not much for the heat of direct sunlight, they tend to feed on the interior of the plant during the day and are more easily spotted when they move to the outside of the plant at dawn and dusk. Hornworm damage usually begins to occur in midsummer and continues throughout the remainder of the growing season.