White Pine Weevil
Pissodes strobi (Peck)


Hanson, T., and E. B. Walker. [n.d.] Field guide to common insect pests of urban trees in the Northeast. Waterbury, VT: Department of Forests, Parks and Recreation. http://www.state.vt.us/anr/fpr/forestry/pubs/pest.html


Coleoptera: Curculionidae

Hosts: White pine, Norway spruce, other spruce and pine species, Douglas fir

Evidence: On sunny days in early spring, look for adults (a) near terminal buds. Pitch flow from feeding and egg-laying punctures is common in the leaders of infested trees (b). Tops may be stunted, drooping or dead by mid-summer (c). Dead terminals sometimes take on the appearance of a shepherd's crook. Two or more whorls can be afffected and occasionally smaller trees may be killed.

Life Cycle: Adults overwinter in the duff under infested trees. They emerge in very early spring to begin feeding and egg-laying in last year's terminal shoot. Upon hatching, larvae tunnel downward beneath the bark, girdling the leader (d). Pupation takes place in the oval chip-lined cells beneath the bark in the feeding channel. Adults emerge in July and August and drop to the ground.

Management: Flagged terminals should be pruned out below the larval tunnels and destroyed as soon as they are seen. When infestations are heavy, treatment of terminals in early spring with a residual insecticide can eliminate adults as they are feeding, but before they begin ovipositing.

a. Pitch flow is associated with feeding and egg-laying

b. Dead terminal caused by White pine weevil

c. Larvae tunnel down the infested leader, girdling the terminal.

Photo Credits:

Figure a: E. Bradford Walker, Vermont Department of Forests, Parks and Recreation, Waterbury, VT.

Figure b: E. Bradford Walker, Vermont Department of Forests, Parks and Recreation, Waterbury, VT.

Figure c: E. Bradford Walker, Vermont Department of Forests, Parks and Recreation, Waterbury, VT.

References:

Drooz, A.T. 1985. Insects of Eastern Forests. USDA Forest Service Miscellaneous Publication 1426. p 328-329;

Johnson, W.T. and Lyon, H.H. 1991. Insects That Feed on Trees and Shrubs. 2nd edition. Cornell University Press. p 54-55;

Martineau, R. 1984. Insects Harmful to Forest Trees. Agriculture Canada Government Publishing Centre, Supply and Services, Ottawa. p 61-63;

Rose, A.H. and Lindquist, O.H. 1973. Insects of Eastern Pine . Canadian Forest Service Publication 1313. p 25-27.

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