What's eating my white oak?

White Oak hosts more insect species than almost any North American tree, including spongy moth, oak leafrollers, various borers, and dozens of gall wasps. Squirrels bury a large proportion of acorns. Deer browse saplings. Healthy established trees tolerate most defoliation; recurring stress plus borers is the lethal combination.

Complete defoliation of crowns in outbreak years; weakened trees susceptible to borer attack; egg masses overwinter on bark Bt spray on young caterpillars in May; scrape egg masses; sticky trunk bands; coordinate with local cooperative extension during outbreak years

Leaves rolled and tied with silk; caterpillars feed inside rolls; heavy infestations cause ragged, browned foliage in spring Bt or spinosad spray when caterpillars are small; natural parasitoids usually keep populations in check; intervention rarely needed on mature trees

Dieback of large limbs; frass and sawdust at entry points; woodpecker activity on trunk signals larval presence Avoid drought stress and bark wounds; remove and destroy infested wood; preventive imidacloprid bark spray on high-value trees

Large, visible galls on leaves, twigs, and acorns; Apple gall, bullet gall, wool sower — cosmetic but reduce acorn yield No practical chemical control; prune gall-bearing twigs in winter; healthy trees outgrow cosmetic damage