What's eating my european larch?

European Larch (Larix decidua) is most commonly attacked by the larch adelgid, which causes woolly tufts at needle bases and early needle drop. Larch casebearer moths mine needles brown. Squirrels strip bark in spring, and deer browse or fray stems. Bark beetles exploit drought-stressed or injured trees.

Woolly white tufts on needles and shoots; premature yellowing and needle fall; distorted shoot growth; pineapple galls on spruce in mixed plantings Horticultural oil or insecticidal soap in late winter; systemic insecticide (acetamiprid) for persistent infestations; ensure good air circulation around bonsai

Tips of needles killed and turn brown from early spring; small silk cases attached to shoots; repeated attacks thin the canopy visibly Remove fallen needles to reduce pupae; natural parasitoids are very effective — reserve pyrethroid sprays for severe cases; apply in early spring at larval emergence

Bark peeled from upper branches and leaders in late spring; young trees can be ring-barked and killed; bonsai leaders destroyed Squirrel guards on trunks; metal bench legs with cone baffles; remove food sources near display area

Pitch tubes and resin bleeding; serpentine galleries under bark; yellowing and death of crown sections Maintain tree vigour with correct watering and fertilising; promptly remove and dispose of infested wood; no curative chemical treatment once beetles are under the bark