Found this caterpillar after it had eaten nearly all the leaves on my tomato plant. Located in Louisville, KY. It was a pretty quick eater – took the whole plant down in about 48hrs. There was another smaller caterpillar (same type) on the plant.
Your caterpillar is the Carolina sphinx or tobacco hornworm. It feeds on all of the solanaceous plants which include tomato, potato, eggplant and peppers.
Like you noticed, if you find one, there are usually more. The most common sign of them is stripped foliage and the dark droppings they leave after eating.
The adult moth is large, gray, and has six pairs of yellow spots on its abdomen. They fly at dusk and can be mistaken for a hummingbird. The moth feeds on nectar of deep-throated flowers like honeysuckle, moonflower, or petunia.
This caterpillar has 7 angled white lines along the side while its relative the tomato hornworm has 8. The tobacco hornworm also has a red tail while the tomato hornworm has a black tail…seems like it should be the other way around!
There are 2 or more generations per year depending on location. They are found thru out North America.
They can be a pest of tomatoes, as you have learned the hard way. There are parasitic wasps that lay eggs in the hornworms that keep them under control most of the time. If you see tufts of white little cotton-ball looking things on the caterpillar…do not kill the caterpillar! Those are the good bugs controlling your pest. That hornworm will not eat anymore…it will die since the wasp has eaten it from the inside.
If you need to control them, just pick off and smash or drop in warm soapy water.
This caterpillar does not bite or sting.