228 



PROTECTION AGAINST INSECTS. 



In the case of the Scots pine the attacks of the beetle cause 

 the development of numerous shoots from dormant buds ; the 

 spruce is sooner killed than the pine. 



On plants over six years old, only those parts from 1 to 5 

 years old are attacked, as the six-year-old bark is too hard for 

 the insect. 



The damage done is much greater in the spring than late in 

 the summer or in the autumn. 



Figs. 92, 93, and 94. Youug spruce plants gnawed by //. abictis, Fabr. (Natural 

 size.} In Fig. 94, a indicates the gnawed parts, b those still covered with bark. 



Freshly planted, extensive, sunny clearings near old woods 

 are preferred by the beetle; especially those in which the 

 stumps have been left in the ground, or not thoroughly 

 extracted. The beetle does not appear at altitudes over 3,000 

 to 8,300 feet. 



d. Protective Rules. 



The best means of prevention consist in supplying this 

 destructive insect with as little opportunity as possible for 



