Redbud lead discoloration/infestation?
We think this looks like a type of leaf scorch due to drought and heat.
All you can do is water during dry periods and make sure mulch is no thicker than several inches and keep away from the trunk.
The insect looks like fall webworm. In any case, there is nothing you can do. The cosmetic damage is done and nothing will bring back healthy foliage at this point in the season. Many shade trees can tolerate caterpillar feeding damage; by this time of year, the trees have stored enough carbohydrates (food reserves) to be able to put out healthy growth again next year. Here is more on fall webworm. https://extension.umd.edu/hgic/topics/fall-webworm-trees