Deciduous plants.
Nightly they will destroy new tree growth May through June. In several nights the bug can clear new growth from tree tops. It is common they will cut new growth shoots.
Evidence of their activity is thinning of leaves. Also make note of leaves whole or partially consumed in the lawn. Finding two to three inches of new tree growth in the lawn is also evidence of their activity.
Pin oak is a common tree for June bug infestation.