Sounds like a bad worm that has its days numbered. There is a parasitic wasp that lays it's eggs on the worm. This worm is a goner and nature has done your work. If they're any more worms on your plant they will meet the same demise.

Leave it alone,help is on the way.

Not necessarily, NCtom. Those braconid wasps kill way too many good moth and butterfly species. It's better to destroy them. I only wish the nightshade-eating Manduca sphinxes were their only prey.

Sorry Tomato Worm59. I look at as nature at work. Curious now though, are Braconid wasp are indigneous to the US or were they introduced?

I don't really know. I presume they are native. Yes, it is nature at work, but since so many people have deliberately distributed the braconids, a lot more than hornworms are dying.

I'm a first time grower of a large crop of tomatoes -- three plants to be exact. They are really starting to produce. Today, I found a fat (1/4 to 1/2 inches in diameter) worm, an inch or so long on one of the stems. It was the same color as the stem. I wouldn't have noticed it, except for the many, white, egg-shaped objects on its back. I'm guessing that this is a tomato worm. Can anyone tell me if there is a spray or a powder dust to get rid of these things, without poisoning the tomatoes?

These worms are definitely an ugh!. For an hour, it has been crawling on an island in the middle of the bird bath. Guess it is even too gross for the birds to take a chance on.

Oh yuck, I just found a bunch of them on one of my tomato plants too. I sprayed them off with the hose...should I go back and squish them???

Sara, go find a horsenettle or black nightshade to relocate them to.

Jim, use some Dipel or Bt. It will NOT make your maters toxic. Next year, plant a few extra tomato plants for the sphinx as well as yourself. One big caterpillar will not kill the established plants. If you have 2-3, just move them around from plant to plant. You have 3 to work with.

Plant some tobacco in or near your garden. It is worthless for anything other than feeding hornworms (or making big tobacco farmers richer) anyway, and hornworms just love tobacco whether they're tobacco hornworms or tomato hornworms.

Tobacco is probably the best and richest food source for the Manduca sphinxes. The moths also actively nectar from and pollinate the fragrant flowers. Although the leaf loss is unacceptable to tobacco farmers, the plants are not actually killed by heavy feeding. The deep-throated flowers are visited by bees, but the long-tongued sphinx moths are the primary pollinator of flowering as well as commercial tobacco [Nicotiana] which makes it mutualistic symbiosis, just as the sphinx and Datura depend on each other.