The parasite had an avenue for invasion along the entire axis of the American chestnut's range. One to several females lay a cluster of 3 to 5 eggs in a bud. Some buds may contain 25 eggs. The eggs hatch in 40 days. Larval growth is very slow during autumn and winter.
Trees suffer severe damage and often die.
As observed in Georgia, adults emerge from the galls during late May and early June. The new generation then oviposit in the buds to continue their life cycle. Recently the gall wasp was found in Tennessee, the home of Dr. Craddock. The American Chestnut Foundation.