Pine Tube Moth - Argyrotaenia pinatubana
by Rayanne D. Lehman
This minor pest of eastern white pine is best recognized by the symptoms it produces rather than by the appearance of the insect itself. Its damage is purely aesthetic and control is rarely warranted.
Distribution and Hosts: Pine tube moth occurs in eastern North America, from Canada south to Florida and west to Wisconsin, throughout the range of its principal host, eastern white pine. A related species, the jack pine tube moth (Argyrotaenia tabulana), causes similar symptoms on jack, lodgepole, and whitebark pines in the Rocky Mountain states and the Canadian provinces of Alberta, Manitoba, and Saskatchewan.
Identification: These small, slender moths have wingspans of 14 mm. Two off-white oblique lines are found on the reddish-orange forewings. When the moth is at rest, these wings conceal the smoky-colored hindwings and gray to tan body. This coloration effectively camouflages the moths when they rest near unopened buds (Fig. 2).
The pale green larvae reach 12 mm at maturity. Identification of pine tube moth is generally accomplished through symptoms, rather than examination of larvae or adults.
Life History: There are two generations of pine tube moth each year in Pennsylvania. Adults emerge from overwintering pupae in early- to mid-April, about the time spruce spider mite eggs hatch (personal observation). This is several weeks earlier than the May emergence reported in the literature (Johnson and Lyon 1988). The second generation adults are reported to appear in July.
Eggs are deposited on the needles. Upon emergence, larvae spin silk and tie 5-20 needles together to form a tube. The caterpillars lie within this silk-lined tube, moving to the open end to feed on needle tips. When the tube walls (needles) have been eaten down to 1 inch, partially developed larvae will abandon their tubes and begin constructing new ones. First and second generation larvae are active from 91-246 and 1151-1514 growing degree days (base 500F), respectively (Clark 1993). When feeding and development is completed, larvae pupate inside the needle tubes.
Damage: Pine tube moth is a minor pest of eastern white pine. The damage caused is purely aesthetic and may even go unnoticed until the empty tubes turn brown in late summer. Rarely, specimen white pines in a landscape may appear ragged due to the action of this pest. Control is generally not warranted and would be extremely difficult since the larvae are protected inside the needle tubes.
Clark, S. 1993. Using growing degree-days for insect pest management. Cornell Cooperative Extension (Suffolk County) Fact Sheet #5. 8pp.
Ives, W.G.H. and H.R. Wong. 1988. Tree and shrub insects of the prairie provinces. Can. For. Serv., North. For. Cent., Edmonton, Alberta. Inf. Rep. NOR-X-292. 327 pp.
Johnson, W.T. and H.H. Lyon. 1988. Insects that feed on trees and shrubs, 2nd ed. Cornell Univ. Press, Ithaca, N.Y. 556 pp.
Vol. 23, No. 2 (Fall 1997)
Entomology Circular No. 186
PDA, Bureau of Plant Industry