Whitemarked tussock moth, Orgyia leucostigma, cocoons were monitored in a black walnut, Juglans nigra, plantation in Michigan from 1978 to 1981. Larvae spun cocoons on the exposed bark of the bole (29.6070), in crevices on the bole formed by pruning wounds (17.5%), beneath limbs (24.2%), and in branch crotches (28.7%). Parasites and predators destroyed 88% of the pupae in their cocoons. The tussock moth population, although moderate to high in the egg stage, decreased sufficiently in the larval stages each year to cause no more than 5010 defoliation to individual trees.
Wilson, Louis F.
"Location and Condition of Whitemarked Tussock Moth (Lepidoptera: Lymantriidae) Cocoons in a Michigan Black Walnut Plantation,"
The Great Lakes Entomologist: Vol. 24
, Article 4.
Available at: http://scholar.valpo.edu/tgle/vol24/iss3/4