It could be a super worm. I saw trees totally stripped of leaves in early June. The next few years could see a caterpillar population boom. White oaks are especially susceptible, he said. Extremely dry conditions offer the flip side of the weather coin.
Plants are under a lot of stress when they dry out and it can lead to insect problems.
It weakens the plant in general and then the next year they will be even more susceptible. Birch trees, he added, will become more susceptible to borers, although the problem may not become apparent until the following year. Mulch with care Mulch is a common prescription for dry weather. In addition to being unsightly, weeds will compete with a plant for water and nutrients. The smaller, shredded mulch works better than big chips.