The photos that you sent are most likely signs and symptoms of the orangestriped oakworm. This is a late season pest that feeds on oak and other tree species. Looks like the damage is already done and no control is necessary at this point. Usually by this time of year the trees have stored enough energy to be able to take the defoliation in stride.

Photo on the left shows pupae. The droppings on the pavement look like caterpillar droppings and the photo on the right shows the foliage is defoliated except for the midribs on the leaves.

Next year about this time or a little earlier you should monitor for the caterpillars. Mature larvae are about 1 1/2 inches long. They are black with eight orange stripes and two black spines behind the head. Look for clusters of caterpillars feeding near defoliated areas. Jar the branches and some may drop to the ground making collection and identification easier. The caterpillars feed in clumps on the ends of branches. Older caterpillars are defoliators. When populations are small defoliation usually occurs one branch at a time.

You can prune out branches or knock them down with a pole pruner to make collections easier. Drop into a bucket or soapy water. If the caterpillars are small (under an inch) and are not able to prune, you can spray with Bacillus thuringiensis (Bt), a biological control that does not harm humans or other insects

Now to lessen any further stress, water during dry periods, make sure mulch is no thicker than two inches and keep away from the trunk.   and as always, protect from mechanical damage from string trimmers/mowers.
mh