INSECTS INJURIOUS TO FOREST TREES 337 



stand that their personal interest demands that proper action be taken in 

 cooperation with other interests, according to reliable advice. 



These general suggestions are based upon actual demonstrations of 

 successful control, some of which may be cited by way of illustration. An 

 alarming outbreak of the eastern spruce beetle in northeastern Maine in 1900 

 and 1901 was controlled by the concentration of regular logging operations in 

 the areas of infested timber, placing the logs in lakes and streams and driving 

 them to the mills on the Androscoggin River. Thus, with little or no addi- 

 tional expense there was a saving to one firm, according to its estimate, of 

 more than one hundred thousand dollars. 



Complete control of the hickory bark beetle, threatening the destruction 

 of hickory trees on Belle Isle Park at Detroit, Michigan, in 1903, was effected 

 by felling and removing the infested trees, converting them into merchantable 

 products, all without cost to the park commission. 



An extensive outbreak of the Black Hills beetle in the vicinity of Colorado 

 Springs in 1905 and 1906 was brought under control through the efforts of 

 the private owners and of forest officials in the adjoining national forest. It 

 was accomplished by cutting and barking about one thousand beetle-infested 

 and beetle-killed pine trees. The cost of the operation was largely, if not 

 entirely, covered by the utilized felled timber, although there was considerable 

 unnecessaiy expense involved through the felling and barking of trees from 

 which the beetles had emerged and from the unnecessary burning of the bark 

 and crop. 



Another striking example of what is possible in the way of controlling this 

 most destructive enemy of the pine timber of the central Rocky Mountain 

 region, was shown on a large private estate and the adjoining Pike National 

 Forest in Colorado. In the spring of 1907 a ranger of the Forest Service, under 

 instructions from the Bureau of Entomology, examined the timber on this 

 estate and found that the Black Hills beetle had been making depredations 

 for the past ten years or more, resulting in the death of the choicest timber 

 to the extent of more than 800,000 board feet. At the time of examination 

 about 65,000 board feet was infested. The owner was notified of the conditions 

 by the Bureau of Entomology, but no action was taken. Another examination 

 in the autumn of the same year showed that the infestation had increased 

 fourfold. This led to the prompt adoption of the recommendations and by 

 May of the following spring, 1908, a small number of trees on the national 

 forest was cut and barked to kill the insects in the inner bark and one 

 thousand trees on the private estate were felled, the logs converted into lumber 

 and the slabs burned, which accomplished the desired purpose of destroying 

 the broods of beetle. The owner realized a sufficient revenue from the timber 

 to cover the expense and leave a net profit of over $1,200. Examination of the 

 area in the fall of 1908 showed that this effort to control the beetle was a 

 complete success. Thus the average death rate of about 100,000 feet of timber 

 annually for ten years or more was reduced to a minimum at a net profit on 

 the cost. 



In 1909 a threatening outbreak of mountain pine beetles in the Snowy 

 Mountains of Montana adjacent to and within the Jefferson National Forest 

 involved more than 1,500 infested and dying trees. Thirteen hundred and' 

 fifty-five trees were cut and barked to kill the broods of beetles. Four hundred 

 and twenty-two trees were cut at firivate expense, and seven hundred and 

 eighty-three at the expense of the Forest Service and the remainder by local 

 owners. The average cost for felling and removing the bark from the infected 

 portion of the trunk was thirty cents per tree. Careful examination in 

 December, 1909, of the area showed that while some fifty-six trees had been 



