doubtful that such attacks produce permanent damage if the trees are healthy. 
Similarly, mature trees repeatedly infested in the forest or in eastern white pine 
plantations evidently suffer no serious harm. 
Sat 
F-519567 
Figure 28.—Fraser fir killed by the 
balsam woolly adelgid, Ade/lges 
piceae. 
Courtesy Conn. Agric. Exp. Stn. 
Figure 29.—Infestation of the pine bark 
adelgid, Pineus strobi, on the trunk of 
pine. 
85 
