INSECTS WHICH KILL FOREST TREES. 7 



trol the beetle was a complete success. Thus the average death rate 

 of some 100,000 feet of timber annually during the past ten or more 

 years was reduced to a minimum, at a net profit on the cost of doing it. 



In addition to infested trees disposed of by the Forest Service in 

 timber sales, 165 infested trees in one section of the Las Animas 

 National Forest were cut and barked in May and June, 1908. at a 

 direct cost of $177.50, and at the same time a considerable amount of 

 infested timber was disposed of by sale in the Wet Mountains section 

 of the San Isabel National Forest. This had a decided effect in 

 checking the ravages of the beetle in both of these forests and it was 

 followed up in the latter forest the next spring (1909) by the proper 

 disposal of over 1,000 infested trees by free use, ranger labor, and 

 direct expenditure of funds appropriated by the Forest Service. 

 According to the forest supervisor's report, 80.7 per cent of the 

 infested trees were treated, ranging from 70 per cent to 92.5 per cent 

 on the five units of infestation: 795 trees were treated (535 barked, 

 and 260 felled and bark scorched) at the expense of the Forest Serv- 

 ice, including salary and expenses of rangers. The cost per tree was 

 about 60 cents for felling and barking, and ranged from 52 to 78 

 cents for felling and scorching the bark on the infested trunks. The 

 average cost per tree was 68.2 cents. Six hundred and twenty-six 

 trees were treated by temporary labor, at an average cost of 61 cents 

 per tree under contract at $1.50 to $2 per hundred feet in length of 

 trunk peeled. The same rate was allowed for scorching the infested 

 bark instead of removing it. Two hundred and seventy-five trees 

 were treated under administrative use without cost to the Forest 

 Service. 



In September, 1909, a very thorough examination was made of 

 the timber in and adjacent to the areas involved in the control opera- 

 tions, and it was found that the thorough, prompt, and proper manner 

 in which the instructions of the Bureau of Entomology were carried 

 out in this case resulted in bringing the beetle under complete control. 

 Only 7 trees had been successfully attacked by the beetles which had 

 emerged from some 400 infested trees which were not cut during the 

 previous control operations. Over 100 trees w^ere found that had 

 been attacked by the beetles, but, owing to the limited number of 

 the latter, the trees were able to resist them and recover. 



It is noAv evident that the control operations carried on in southern 

 Colorado during the past three years, on the Trinchera estate near 

 Fort Garland in 1906, in the Las Animas National Forest and Wet 

 Mountains section of the San Isabel National Forest in 1908, and 

 the more extensive work in the latter area in 1909, had a far-reaching 

 effect in bringiug the Black Hills beetle under control within the 

 forested areas of southern Colorado, and that the loss of timber 



[Cir. 125] 



