species of pine within its range, and occasionally spruce, fir, Douglas-fir, and larch. 
The adult is light reddish-brown to dark brown and from 5.5 to 9 mm long (fig. 
163A). Full-grown larvae are grublike, legless, 10 to 12 mm long, and white except 
for a brown head and small brown area at the rear. Mature larvae have a row of 
small, pale-brown tubercles along each side of the body. The adult is frequently 
confused with lighter specimens of the black turpentine beetle, especially where the 
ranges of the two species overlap. 
The habits of the red turpentine beetle are very similar to those of the black 
turpentine beetle. It, too, usually attacks trees of reduced vigor, but can attack 
apparently healthy trees. Individual trees or groups of trees and fresh stumps are 
attacked most frequently. However, destructive populations may also develop in 
trees disturbed by logging, fire, or land clearing. Injured trees around construction 
sites or adjacent to piles of fresh lumber are infested frequently. Trees of pole size or 
larger are most susceptible (///5). 
In the colder parts of the insect’s range, the winter is spent chiefly in the adult 
stage but, to some extent, in the larval stage. In the warmer parts of its range, adults 
fly intermittently during the warmer winter months. Attacks on standing trees are 
initiated by females boring through the bark to the wood, usually in the basal 2 m of 
the tree, but sometimes to a height above 3.5 m. Like those of the black turpentine 
beetle, these attacks are characterized by the presence of pitch tubes on the bark 
(fig. 163C). The gallery first runs horizontally or slightly upward, then it turns 
downward. When the attack is made just above the ground line, the gallery may be 
continued below ground line along a large root. A fully developed gallery may be 1 
F-494425, 494422, 494420 
Figure 163.—Red turpentine beetle, Dendroctonus 
valens: A, adult; B, gallery with mass of eggs along 
the side; C, pitch tubes at base of pine. 
348 
