This morning I took 30 of these buggers off one little Texas Mountain Laurel tree--all the tree's new growth had been skeletonized before I saw them. These caterpillars become a brown night-flying moth. Judging by my yard, the moths are prolific reproducers.
To find out if your trees are infested, look for loose webbing on new leaves, or leaves eaten into a skeleton.
It doesn't take long for a clutch of cats to chew through a flush of leaves; and losing the new leaves slows growth.
According to Texas A&M's website, "Plant health is generally unaffected by feeding unless large numbers of caterpillars cause heavy defoliation (leaf loss)." The site advises using manual control otherwise.
If you find webbing, brush it off and take the caterpillars off by hand-picking or blasting with a stream of water.
It's easiest to find the caterpillars in early morning while they're still in the webbing. They look hairy but don't sting. If you're finicky, wear gloves.
And think of the purple flowers you'll have next spring.