The females drill holes in the chestnut bur with their beaks, then insert eggs into the cavity. Eggs hatch in about 10 days. After feeding 4 or 5 weeks within the nut, they chew exit holes, leave the fallen nut and enter the ground where they form earthen cells 3 to 10 inches below the surface. Larvae remain in these cells throughout the winter and following summer. Adults mate, feed, and the females begin to lay eggs in early August.
Females chew holes through the bur and into the nut to make a suitable place in which to lay eggs.
Each female lays about 25 eggs which hatch in about one week. Larvae pupate in late spring and early summer. Adults begin to appear about the first of August. Mites Several species of mites attack chestnuts causing brownish, scorched appearing foliage. Prolonged infestations can damage trees and the chestnut crop.