Pine Bark Adelgid
Hosts: Primarily white pine
Evidence: Look for white woolly material on trunks (a), branches, and at the bases of needles in early spring. Heavy infestations may give the bark a white appearance. Under the wax, you may find the dark-colored adelgids. The wax-covered brown eggs are clustered near females.
Life Cycle: There are several generations per year. After overwintering as immatures on the bark, adelgids begin feeding and secrete large amounts of waxy material over their bodies. When mature, females lay eggs. Crawlers and winged individuals emerge from these eggs. Wingless forms settle on the tree and reproduce repeatedly.
Management: Healthy trees are not usually affected by the pine bark adelgid, and light to moderate infestations don't usually warrant control. If unsightly, the adelgids and wool can sometimes be washed off with water, using a strong stream from a garden hose or insecticides can be applied if desired.
Figure a: Ronald S. Kelley, Vermont Department of Forests, Parks and Recreation, Morrisville, VT.
Drooz, A.T. 1985. Insects of Eastern Forests. USDA Forest Service Miscellaneous Publication 1426. p 84-85;
Johnson, W.T. and Lyon, H.H. 1991. Insects That Feed on Trees and Shrubs. 2nd edition. Cornell University Press. p 76-77;
Martineau, R. 1984. Insects Harmful to Forest Trees. Agriculture Canada Government Publishing Centre, Supply and Services, Ottawa. p 69;
Rose, A.H. and Lindquist, O.H. 1973. Insects of Eastern Pines. Canadian Forest Service Publication 1313. p 94.