The adult weevils spend the winter in the litter. They emerge from hibernation 
during March, April, and May in response to temperature, and feed on the cambial 
tissue of the main stems of the host. Most of the feeding is done within 25 cm of the 
terminal buds. The eggs are laid in some of the cavities made'in the bark by the 
females when they feed. Eggs hatch in 7 to 10 days and the young larvae bore 
downward in the cambium under the bark. When there are many larvae they feed 
side by side in a ring around the stem. Toward the end of July the larvae begin to 
make chambers in the woody part of the stem. The shreds of wood removed are 
placed on top of the chamber to form a chip cocoon. The larvae pupate in the 
chambers and 10 to 15 days later emerge as adults. The adults disperse over all 
parts of the tree and feed until late fall; this differs from their spring-feeding habit. 
Sometimes, this feeding alone is severe enough to kill entire shoots. 
The white pine weevil is the most serious insect pest of eastern white pine in 
North America. Its damage results in two types of loss: (1) reduction in volume, 
and (2) lumber degrade in the remaining volume. Studies in New Hampshire 
showed an estimated volume loss of 40 percent in the saw-log portion of sawtimber 
trees and 70 percent loss in the portion above saw-log limits of merchantability. The 
average loss in pole-size trees was 13 percent (/254). 
The first evidence of attack in the spring is pitch flow from feeding punctures on 
the terminal shoots (534). Later, the new growth appears stunted, and finally, the 
needles wilt (fig. 151B). Trees up to | m tall may be killed. Killed terminals on 
taller trees are replaced by one or more branches of the topmost living whorl 
assuming vertical growth. This results in crooked or forked stems (fig. 151C). Trees 
suffering this type of damage for several years become multiple-stemmed, cabbage- 
shaped, and worthless. 
The white pine weevil has been studied intensively, and much has been learned 
about its biology, ecology, and control. As a result of these investigations, the 
following management practices have been recommended for reducing losses to 
white pines: (1) planting white pines with hardwoods or under a hardwood cover; 
(2) planting white pine on medium soils only, where soil matting or hardpan does 
not occur within | m of the surface and where the trees will not suffer from 
competition with hardwoods, or jack or red pines; (3) selecting and pruning the 
least injured pines for an improved final crop in heavily infested stands; and (4) 
removing less desirable trees from white pine stands (236, 309, 762, 523, 1362). 
Other types of indirect control, such as that exerted by insect parasites, predators, 
and birds, are helpful in preventing excessively high weevil populations but are 
incapable of preventing intolerable levels of loss (525, //91). Key factor analysis 
suggests that larval, pupal, and winte’ submortalities are the major influences on 
population change (308). Drench-spr.y of terminals at the time adults emerge from 
hibernation provides protection (5/6). 
The northern pine weevil, P. approximatus Hopkins, a close relative of the 
white pine weevil, occurs from the Atlantic Coast to Manitoba in Canada and 
southward to Minnesota and North Carolina in the United States. Its preferred hosts 
appear to be red and Scotch pines, but it also attacks eastern white, pitch, jack, 
shortleaf, Virginia, Table Mountain, and Austrian pines, and red, black, and white 
spruces. 
The adult is similar to the white pine weevil. It is larger, and the snout is 
proportionately longer. The distal brown and white spots on the elytra rarely overlap 
in P. approximatus. This is the single most reliable morphological feature by which 
these two species can be distinguished from one another (4/4). The taxonomic 
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