726 A NATIONAL PLAN FOB AMERICAN FORESTRY 



Such a picture as that presented does not attempt to appraise 

 insect losses in areas of great scenic value. The importance of the 

 forest cover in national parks, game preserves, and recreational areas 

 cannot be estimated in monetary values. Here the esthetic and 

 protective values far exceed that of the commercial timber. Al- 

 though not so directly appreciated by the visitor one of the greatest 

 attractions in these areas is the forest, as much of the natural beauty 

 of parks, camp sites, etc., is in reality dependent upon a green forest 

 cover. Trees also give protection to the birds and other animals. 

 For these reasons insect depredations which mar the scenic beauty 

 or destroy the protective value of the forest cover must be controlled 

 regardless of cost. 



There is another less appreciated aspect of the insect activities in 

 our forests which each year is becoming increasingly important. In 

 some forest types insects often are one of the chief limiting factors in 

 successful management. Insects frequently "throw the monkey 

 wrench", so to speak, into our well organized plans aimed at the 

 production of continuous forest crops. In the western white and 

 lodgepole pine types of the northern Rockies, bark beetles so affect 

 the proportion of species in these stands as to convert the resulting 

 forest into one of entirely different composition, often of inferior 

 species, necessitating an entire reorganization of management plans. 



All kinds of forest products from the moment the tree is felled and 

 for many years after the wood is in use are subject to destruction by 

 insects. Insects cause injuries in the living tree which show up as 

 defects in the lumber, thus greatly reducing its value. Green saw- 

 logs and storm-felled timber, green sawn and seasoned lumber, rustic 

 construction, poles, posts, crossties and all manner of finished products 

 from flooring to furniture are attacked. The losses in finished prod- 

 ucts are particularly heavy ^ in that the cost of manufacture and 

 replacement must be taken into consideration. However, with this 

 type of damage it is much more practical to prevent losses. The 

 most recent attempt to evaluate the losses from this source places the 

 damage at from % to 5 percent of the total value of various classes 

 of products. 1 



DEVELOPMENT IN FOREST INSECT CONTROL 



Control work against tree-killing bark beetles conducted by three 

 Federal agencies the Forest Service, the National Park Service, and 

 the Bureau of Indian Affairs and by private owners as well, has 

 been an important part of the forest protection program in the 

 Western States and incidentally illustrates marked progress in 

 research and administration. 



The first project was conducted by the Forest Service in the Black 

 Hills National Forest, S.Dak., in 1906, when $2,700 was expended in 

 an effort to check an epidemic of the Black Hills beetle. Since then 

 many projects have been carried out, some of them covering exten- 

 sive areas. A total of something over $1,000,000 has been expended 

 through 1931. The annual expenditures from 1906 to 1921 were 

 small rarely over $20,000 and usually much less. Since 1922, with 

 the fuller appreciation of the importance of the losses brought about 

 through the activities of these insects, increasing amounts have been 



i Statistical Bulletin. No. 21, U.S.D. 



