I had 6 full grown trees in SC. I would have worms almost every year... Until they started spraying cotton on the farm across from me. Great catfish bait... Along with about anything else that swims.
If you find the trees chances are there are small one growing near by. Dig them up and plant them where you want them. They are easy to grow.
Also, if you find worms you can put them on your trees and when they go in the ground, chances are next year the moth with lay on your trees and yo can have some.