7 
ders of dense stands wherever the soil and other conditions are most 
favorable for rapid growth. 
The unfavorable conditions for infury are slow growth, dense pure 
stands, and mixed stands of pine and hardwood. . 
Under the former conditions the thrifty, vigorous terminals are espe- 
cially favored as breeding places for the weevil; and where these are 
killed, the vital energy of the tree is thrown into the lateral branches. 
Open stands, therefore, favor the development of large branches and a 
spreading crown, while under conditions unfavorable to weevil injury 
the terminals are smaller and, even if they are killed, the close stand or 
lateral shade will tend to produce an upward or vertical growth of the 
topmost branches, the stronger one taking the lead and soon repairing 
the damage. 
NATURAL ENEMIES. 
Numerous parasitic and predatory insect enemies attack the develop- 
ing broods in the terminals. Woodpeckers, also, feed on the matured 
Fig. 6.—Barrel for terminal shoots infested by white-pine weevil, with wire screen over end allow- 
ing escape of parasites but preventing escape of weevils. (Original.) 
larvee, pup, and adults. Some of the larve apparently die from 
disease, and when large numbers of them are crowded together the 
larger ones appear to feed’on the smaller ones, so that on the average 
not more than from 3 to 5 per cent of the hatched larve ever reach 
maturity and emerge from the infested terminals. However, each 
female is capable of depositing more than one hundred eggs each year 
for several years; thus the depredations are continuous. During some 
years the damage will be slight, while in other years it will be very 
severe, the amount of injury depending on the number of adults that 
survive and the conditions presented for their attack and development. 
METHODS OF CONTROL. 
It will be seen that in the successful control of this pest, as in the 
control of forest insects in general, much depends on special features in 
