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. 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. Damage in the field was visible by May in 2004. In 2005 we have seen damage in July. Hosts include maple, specifically red maple, silver maple, sugar maple, bigleaf maple, and boxelder (Furniss and Carolin, 1977; Johnson and Lyon, 1991).
In Oregon the moths are reported to emerge in July and August (Schuh and Mote, 1948). 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.
Management is difficult as the larvae enter the shoots soon after emergence of the first two pair of leaves (Hale and Halcomb, 1994). Recommendations from the work of Hale and Halcomb 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. Bifenthrin (Talstar 10 WP) was the most effective treatment in their studies.
References cited:
Vanek, S. 2011. Maple Shoot Borer: Biology and Management of a Prominent Nursery Pest. University of Kentucky Extension. 9 March 2012.
Furniss, R.L. and V. M. Carolin. 1977. Western Forest Insects. USDA Forest Service. Miscellaneous Publication No. 1339. 654 pp.
Hale, F.A. and M. Halcomb. 1994. Shootboring caterpillars, Proteoteras spp. (Lepidoptera: Tortricidae). Major pests of red maples in Tennessee nurseries. Proc. Southern Nurserymen's Association Research Conference. 39: 178-179. Web link
Hale, F.A. and M. Halcomb. 1995. Timing and control of Proteoteras aesculana (Lepidoptera): Tortricidae) in Red Maple. Proc. Southern Nurserymen's Association Research Conference. 40: 198-200. Web link
Johnson, W.T. and H.H. Lyon. 1991. Insects that Feed on Trees and Shrubs. Cornell University Press. 2nd edition revised. 560 pp.
Schuh, J. and D.C. Mote. 1948. Insect Pests of Nursery and Ornamental Trees and Shrubs in Oregon. Agricultual Experiment Station, Oregon State Univeristy (College), Corvallis. Station bulletin 449. 164 pp.
Maple tip bore hole on red maple closeup
Photo: Anonymous
Maple tip borer larva in red maple stem closeup
Photo: Anonymous
Maple tip moth damage on the maple terminal closeup.
Photo: Rosetta
Maple tip moth larva damage on the maple terminal closeup.
Photo: Rosetta
Maple tip moth damage on silver maple closeup.
Photo: James Solomon, US Forest Service, Forestry Images