U.S. Department of Agriculture, Forest Service. 1979. A guide to common insects and diseases of forest trees in the northeastern United States. Northeast. Area State and Private Forestry, Forest Insect and Disease Management., Broomall, PA. p. 123, illus.(USDA Forest Service, Northeast Area State and Private Forestry Publication. NA-FR-4)
The white pine weevil is a serious pest throughout the range of its preferred host, eastern white pine. Other hosts, in descending order of preferrence, are Norway spruce, jack pine, Scots pine, pitch pine, and red pine. Open-grown white pines in old-field plantations are highly susceptible to infestation and rapid weevil buildup. Evidence of weevil attack first shows in the spring as pitch flows from feeding punctures on the preceding year's leader. During summer, new growth is stunted; eventually the needles wilt and the bark shrivels, turning a reddish brown. Trees less than 3 feet in height may be killed. The dead leaders are replaced by one or more of the lateral shoots, resulting in a crooked or forked stem. Successive weeviling over a number of years results in multiple-stemmed trees.
The adult weevils overwinter in the duff. They emerge from March to May and crawl or fly to host trees, where they feed on the previous season's leader and deposit their eggs in small niches under the bark. The eggs hatch in 7 to 10 days, and the legless white grubs position themselves around the shoot and feed as a group on the inner and outer wood, tunneling downward. The portion of the branch above the lowest level of feeding dies by late summer. Mature larvae construct pupal chambers in the pith of the terminal shoot, and young adults emerge in 10 to 15 days. They feed on old and new branches until cold weather forces them to hibernate. There is one generation per year.
