48 



There are many other bark-mining beetles and bark and wood- 

 mining grubs which may aid the primary enemy in killing the trees 

 and in the subsequent destruction of the wood. 



The principal enemy of the spruce-destroying beetle and other 

 bark-infesting enemies of the spruce consists of the woodi^eckers, 

 which destroy, it is believed, from 50 to 75 per cent of the broods of 

 the spruce beetle in many hundreds of trees each year. 



Two other enemies of the beetle are of special service in reducing 

 their numbers, a small wasp-like parasitic insect {Brecon simpler) 

 and an ant-like predaceous beetle (Thanasimus nubilus Kl.?). 



The principal methods recommended in this report for preventing 

 losses from the ravages of the beetle may be briefly summarized as 

 follows : 



I. Regulating the winter cutting so as to include as many of the 

 infested, dying, and dead trees as possible, and placing the logs from 

 the same in the water before the 1st of June. 



II. Regulating the summer cutting so that as many recently 

 attacked trees as possible may be cut and the bark removed from 

 their trunks and stumps. 



III. Girdling, early in June, a large number of trees, where logging 

 operations will, or can, be carried on the following summer and winter, 

 in the Aucinity of infested localities, the girdled trees to be felled 

 and the logs containing the broods of the insect attracted to them 

 either peeled or placed in the water before the first of the succeeding 

 June. 



The results of one season's experiment in girdling trees indicate 

 that the best time to girdle spruce for this purpose is when the flow- 

 ers (catkins) are falling from the birch, and while the fire or bird 

 cherry and the hobble bush are in bloom. The girdled trees should 

 be sound and healthy, and not less than 15 inches in diameter. 



The best method of girdling seems to be that of hacking through 

 the bark with an ax into the sapwood and around the trunk 2 or 3 

 feet above the base. 



Suggestions for utilizing the dead and matured living spruce to 

 prevent loss are as follows : 



A large percentage of the dead spruce appears to remain sound and 

 valuable for pulp wood for a longer period than has heretofore been 

 recognized. 



The matured living timber should be cut and utilized as rapidly as 

 possible to prevent insect attack. 



