What's eating my beaked hazelnut?

Beaked hazelnut is a North American native with moderate pest resistance. The hazelnut weevil is still its main nut pest, and the filbert worm is relevant in the western part of its range. Aphids and tent caterpillars affect the foliage. Squirrels, chipmunks, and birds compete actively for the crop, often before nuts are fully ripe.

Female drills into young nut; larva consumes the kernel and exits through a hole, causing premature nut drop. Destroy fallen nuts daily during late summer; kaolin clay at nut set; soil cultivation to expose and kill pupae.

Caterpillar bores into nut, leaving small entry hole and frass; affected nuts drop prematurely or are hollow at harvest. Pheromone traps to monitor adult flight; spinosad spray at first moth catch; remove and destroy all fallen nuts.

Silken tents in branch forks in spring; caterpillars defoliate whole branches, weakening young shrubs. Remove tents by hand when small in early spring; Bt (Bacillus thuringiensis) spray on young caterpillars; no chemical treatment needed on established shrubs.

Persistent raiders that take nuts green and cache them; native shrubs in woodland settings may lose nearly all their crop. Trunk baffles; fine netting over isolated bushes; consider planting a surplus to share with wildlife.