Looking up in your pecan or sweet gum trees, you may have noticed a very spooky webbing being formed around the tips of your branches, as well as the foliation under the webbing.
If you are seeing this, most likely you have an infestation of the fall webworm.
The fall webworm's distribution is the United States as well as southern Canada. The fall webworm uses many deciduous hardwood trees as well as some evergreen trees as its host here in the south. Some favorite host trees of the fall webworm are the hickroy, pecan, persimmon, and sweet gum.