Pine leaf adelgid

Pineus pinifoliae (Fitch) (Hemiptera Adelgidae)

Orientation to pest

Pine leaf adelgid, Pineus pinifoliae (Fitch), is native to North America and feeds alternatively on spruce (Picea) and pine (Pinus). On spruce, galls are produced. On pine, nymphs feeds openly on terminal foliage. In the eastern United States, red (Picea rubens Sargent) and black (P. mariana [Miller] Britton, Sterns and Poggenburg) spruce are the initial hosts, with adults produced there, migrating to white pine (Pinus strobus L.). In the western United States, the initial hosts are Engelmann spruce (Picea engelmannii Parry ex Engelm.), black spruce, blue spruce (Picea pungens Engelm.), and white spruce (Picea glauca [Moench] Voss), and the pine host is western white pine (Pinus monticola Douglas ex D. Don). Two years are required to complete this cycle among tree hosts. Pine leaf adelgid can be an important pest in white pine plantations on young trees. Heavy infestations can reduce growth of pine or even kill trees. Galls on spruce do not damage the health of the tree.

Hosts commonly attacked

This species feeds on red (Picea rubens), black (Picea mariana), Engelmann (Picea engelmannii), blue (Picea pungens), and white (P. glauca) spruce as primary hosts and eastern white (Pinus strobus) and western white (Pinus monticola) pines as alternate hosts.

Distribution

This adelgid is found widely in North America wherever the ranges of its primary and alternative hosts overlap.

Images of the pine leaf adelgid

Whitney Cranshaw, Colorado State University, Bugwood.org 768x512 / 1536x1024	Whitney Cranshaw, Colorado State University, Bugwood.org 768x512 / 1536x1024	Whitney Cranshaw, Colorado State University, Bugwood.org 768x512 / 1536x1024
Figure 1. Close view of pine leaf adelgid, Pineus pinifoliae, on a western spruce host	Figure 2. Fresh gall of pine leaf adelgid on a western spruce host	Figure 3. Old gall of pine leaf adelgid on a western spruce host, after adelgid emergence

E. Bradford Walker, Vermont Department of Forests, Parks and Recreation, Bugwood.org 768x512 / 1536x1024	Ronald S. Kelley, Vermont Department of Forests, Parks and Recreation, Bugwood.org 768x512 / 1536x1024
Figure 4. Adults of pine leaf adelgid on a pine host	Figure 5. Flagging tip on pine, a symptom of feeding of pine leaf adelgid

Important biological control agents related to this pest species

No information is available on the natural enemies of this adelgid. They are likely to be similar to those recorded for other Pineus and Adelges species in North America.

Web links for information on the pine leaf adelgid

• Fact Sheet | ForestPests.org | Vermont Division of Forestry
• Fact Sheet from Maine Forest Service | State of Maine Department of Conservation
• Western Forest Insects | USDA Forest Service
• Pine Leaf Adelgid, Pineus pinifoliae(Fitch) Found Damaging Western White Pine Plantations on Kootenai and Idaho Panhandle NFs | USDA Forest Service, Northern Region, Forest Health Protection

Articles

• Dimond, J. B. 1974. Sequential surveys for the pine leaf chermid, Pineus pinifoliae. Technical Bulletin No. 68, Life Sciences and Agriculture Experiment Station, University of Maine; Orono, Maine, USA, 15 pp.