Katydids are green, about 2 to 3 inches long, and have both long antennae and legs. These insects do not cause any significant damage to trees. Depending on your point of view, their singing may be annoying or just a soothing sound of the summer night. Of the three, fall webworms are the most visible. Silk tents have been showing up in a variety of shade trees.
Close inspection reveals caterpillars inside.
As they feed and grow, these caterpillars make the web larger to cover more foliage. When young, the caterpillars will only eat the upper surface of the leaf, but as they get older they will eat the entire leaf except larger veins and the midrib. When full grown, they drop to the ground to pupate. Don't confuse fall webworm with the eastern tent caterpillar, which is out very early in spring. Likewise, fall webworms should not be mistaken for gypsy moth, which does not make tent-like webs in trees.