Hey, I'm not sure where in 7b you are, but here in EAstern NC, I've had a lot of the inchworms to deal with over the past 2 weeks or so... first found them on my budding apple trees and then on my blueberries (all new plantings).

I used a few applications of the BT bacteria to help dampen their spirits, and it seems after a week or so that they've settled down. The plants are also leafing out so fast that whatever is left hopefully can't keep up. We've had a lot of rain recently and I'd guess the BT is all washed off by now.

Last year when I lived in Raleigh, I had a few tomatoes on my patio and the tomato hornworms got to them... I used the BT and it did the job, but before that I found a number of the big caterpillars with the wasp egg casings... what a sight!

Cheers

If you have caterpillars, larva of several moths or butterflies, that are eating the leaves of your plants the best method of control, in the early stage of their life, is to spray the threatened plants with Bacillus thurigiensis - Kurstaki. There are several strains of BT out there and you do need the right one for the insect you want to control.
However, you also need to decide if control is necessary because it is not always. Due care in what is sprayed is also necessary since many of the insect controls are very broad spectrum and will kill off beneficial insects, includng pollinators, as well as the pests.

If you can ID the caterpillar(s), and/or the associated moth(s), that will make the solution easier. The approach will usually vary depending on the particular caterpillar.

If they are anything like cabbage loopers (which loop or inch along as they crawl), Bt works well. You might have to apply it several times to kill off the different generations.

On top of everyone's good comments, I'd like to know what kind of trees! Knowing the plant species is very important in caterpillar identification.

I have heard of the BT bacteria. That seems like just as much of a natural solution and thank you for reminding me about it. The trees that they really seem to like look to be hickories of some sort. I can try to key them out, but I don't know if I can at this point.

BT just got sprayed today. I couldn't wait for the wasps any longer. Will they spread these bacteria between one another? Reason I am asking is because my roommate was spraying a very tall tree and could only spray so far up. I am hoping that the ones on the ground plants and the trunk will spread this bacterial disease to the ones that are up higher. I am pretty sure that it is a shagbark hickory that they seem to be the most interested in. They ate the magnolias pretty hardcore too. And the roses seemed tasty to some of them. Most of the garden plants seem unpalatable to them. There are irises below the main tree and although tons of the worms had fallen on these and were gripping them the irises didn't have a single bite taken out of them.
I did a little research and found that most trees can survive 2-3 years of severe defoliation and will grow a set of smaller leaves in the same year to replace those that have been munched. We will keep an eye out for these buggers and spray the BT much earlier next year. Thank you for suggesting this solution that did not involve unwanted chemicals. I am looking forward to seeing many a dead inchworm in the coming days. I will keep you posted.

It would nice if we could see a picture of the mature caterpillars doing all of this destruction. Any chance of that?

Growing flowers to attract the wasps would be a long game. Just buy the wasps. There are plenty of BioControl sellers who specialize in beneficial insects which they ship to you door in a day Because such businesses ship live insects, it is critical they are near you. Do a search on Google.

An ecosystem with too many pests is one that needs the balance of more predators. You can make the shift in that balance happen pretty fast if you know what insects you're combating and how to use the predator. They are usually native species as well. Still grow the flowers, to keep the new generation around to breed and lay their own eggs.

We have here in Ma a very similar, if not the same, early spring caterpillar pest that can defoliate whole trees during a bad year. For us it's Winter Moth, and the solution is Trichogramma Wasps released very early, as trees start to bud and the caterpillar eggs hatch. They're tiny green inchworms, and even at their largest they're maybe a half an inch long. They like to hang from trees on a silken line, catching in your hair.

The first year we had moved into our current home, the infestation was surreal. It was also a pretty windy spring, and to make the wind worse, we are on a lake. The wind blew tons and tons of them onto our deck. By evening one day, our red-stained deck was one mass of writhing green. You seriously couldn't see the wood, no exaggeration. That's the year I learned about BioControl and Trichograma.

Nature is wonderful, except when it's too freaky, and I am glad we moved here but even happier for the ability to buy in the good bugs when needed. We've not had another year like that - and though I'm pretty sure it was a once in a decade thing, I also think the wasps were what cut down the levels as fast as they went down in our neighborhood the next year.

When you spray one of the Bacillus thuringiensis products onto a plant the bacterium sticks to the leaves where contact is made and the target species must ingest (eat) tha leaf this bactierium is on. Once the bacterium is in the insects gut it becomes alive and devours the insect from the inside and the insect, now unable to digest the food dies of starvation. The BT bacterium is not going to migrate anywhere and simply stays where you put it.
One of the major reasons this is a good product is because the bacterium must be ingested by one of the target species with the right gut fauna to get those bacterium to come alive and work. There are several strains of the BT and you need to get the right one for your target species, BTK, BTI, BTSD, etc.

Bt paralyzes the gut of the insect, once it is absorbed. It doesn't devour the insect from the inside out. The parasitoid wasps have that job to do!

BT also won't work unless it's ingested.

When you spray a tree branch that is in bud, you are getting the outside of the bud only, not the insides.

The Winter Moths and their allies are so tiny when they hatch near the buds, they crawl right into the center of the bud. Only then do they start to eat, starting with the most tender parts. By the time they get to the outside of the bud, assuming the BT is still there and the worms are still eating, the damage to the tree has been done.

BT is good for full foliage eaters, not for bud-eaters and miners. For that you need something that parasitizes the eggs or can crawl right into the buds/holes after them.