What's eating my japanese beech?

Japanese Beech (Fagus crenata) is attacked by beech woolly aphids (felted beech coccid), scale insects, and caterpillars of several moth species. Squirrels strip bark and eat buds. Deer browse young trees heavily in winter. As a bonsai kept outdoors it is also vulnerable to vine weevil grubs attacking the roots.

White woolly tufts in bark crevices and on undersides of branches; associated entry point for beech bark disease fungus; foliage yellows on heavily infested trees Scrub off colonies with a stiff brush; apply horticultural oil in winter to smother overwintering stages; avoid wounding bark which invites secondary fungal infection

Blister mines or brown patches visible on upper leaf surface; premature leaf drop; significant defoliation in heavy outbreaks Collect and dispose of fallen leaves in autumn; for bonsai, spray with bifenthrin or Bt at leaf-burst if outbreaks are recurrent

Bark stripped from branches and trunk (cambium eaten); buds removed in spring; characteristic spiral or patch bark wounds Use squirrel guards on trunks; site bonsai on metal-legged benches with cone guards; there is no reliable repellent — exclusion is the most effective method

Irregular notches on leaf margins (adult); C-shaped white grubs eat roots — bonsai suddenly wilt and collapse even with adequate watering Apply Steinernema kraussei or Heterorhabditis bacteriophora nematodes to moist compost in late summer; use imidacloprid drench for severe infestations; check root ball when repotting