Pest description and crop damage Maple tip moth, Proteoteras aesculana Riley, also known as maple shoot borer and maple twig borer, is an occasional pest in nursery production in the Pacific Northwest. The moths are dark olive green with yellow and gray mottling. Larvae are pale white to gray and approximately 10 mm long when mature. The head is dark brown and the thoracic shield, yellow-brown. Damage occurs when the caterpillar bores into new growing terminals, causing tip dieback. New terminals must then be trained adding to labor time and costs. Hosts include maple, specifically red maple, silver maple, sugar maple, bigleaf maple, and boxelder.
Biology and life history In Oregon the moths are reported to emerge in July and August. Management is difficult as the larvae enter the shoots soon after emergence of the first two pair of leaves.
Recommendations from the work in Tennessee are that applications of protective insecticides be applied when the first two pair of leaves have come out. Another application 5-7 days later may be necessary on seedling trees due to seedling growth variability.
For more information
Johnson, W.T. and H.H. Lyon (1991), Insects That Feed on Trees and Shrubs, 2nd ed., Cornell University Press (p. 200).
PNW Nursery IPM: Maple tip moth (http://oregonstate.edu/dept/nurspest/maple_tip_borer.htm)