A couple days ago I noticed some of the green tomatoes on the vines had been gnawed on. I thought maybe birds had been pecking at them. Yesterday, while closing up the greenhouse for the night, I saw some poops around and on the tomato plants and thought: maybe rodents. Then I noticed a huge green caterpillar, what I thought was a tomato hornworm. And then I saw more. Then Carol joined me, and she found more, and more, and more. We picked off about forty of them, filling the bottom of an orange Home Depot "Homer" bucket.
This morning we picked off another eight. Some of the tomato plants had been stripped by these bad boys.
I've been growing tomatoes for almost forty years and have never had an infestation of hornworms before. I guess that's why I didn't recognize the signs earlier. I'm sure I'll recognize them early on if/when we ever get more. When we grew fewer tomato plants in our garden, we always planted marigolds around them. Some of my research said that helps prevent hornworms. Maybe that's why we never had them before.
Being on the tomato plants, I automatically thought they were "tomato hornworms". After a little research, I found out that these are "tobacco hornworms", very similar looking to tomato hornworms both as caterpillars and as the adult sphinx moths. Both are in the same genus, and both attack the same variety of plants. The visual differences are: 1) the tobacco hornworms have red horns, while the tomato hornworms have black horns, and 2) the white markings on the sides of the body on the tobacco hornworm are straight lines, whereas on the tomato hornworm they are v-shaped. Not that it makes any difference because they'll both munch on and strip your plants faster than you can imagine. Steve