Damage and symptoms
Damage before shell hardening is caused by the larvae which bore into the fruit. In small nuts the entire kernel is eaten, whereas in large fruit, part of the kernel may remain. A larva can consume several small nuts by moving from one fruit to another. This type of damage is small, and trees are able to compensate for damage because of the large volume of flowers and small nuts produced by macadamia trees early in the season. Fruit with hardened shells cannot be penetrated, larvae then feed on the inside of the husk. Damaged nuts are shed by the tree.