Large Aspen Tortrix
Choristoneura conflictana |
| USDA Forest Service. 1979. A guide to common insects and diseases of forest trees in the northeastern United States. Northeast. Area State Priv. For., For. Insect and Disease Management., Broomall, PA. p. 123, illus. |
The large aspen tortrix is an early summer defoliator of quaking aspen. During epidemic outbreaks, it also feeds on balsam poplar, paper birch, willow, alder, and black cottonwood. Defoliated trees usually refoliate in mid- to late summer. Because new foliage is sparse and individual leaves are smaller, tree crowns appear thin.
The tortrix lays greenish, flat, overlapping eggs in round masses on upper leaf surfaces. The first-instar larvae spin hibernating cocoons in protected locations on the tree trunk, then molt and overwinter in the second larval stage. In the spring at about the time of bud break, larvae emerge, climb the tree and mine the expanding buds. The mature larva is green to black with a black head and anal plate. Pupation occurs in leaves rolled or webbed together on the tree. This pest has one generation per year.
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