INSECT DEPREDATIONS IN NORTH AMERICAN FORESTS. 91 



given out to the public is not only the best available but that it is 

 limited to the range of expert knowledge of the subject possessed by 

 the instructor or investigator. 



Elementary and Technical Knowledge of Forest Entomology fob the 



Forester. 



While it may be desirable that every professional forester should 

 have an expert knowledge of forest entomology, it is rarely possible, 

 even under exceptionally favorable conditions, for him to acquire 

 more than the necessary elementary knowledge, and even this has not 

 been possible under the conditions which have necessarily prevailed 

 in the forest schools, and in the practice of forestry, in this country. 

 Little or no time has been available for acquiring the necessary in- 

 formation from subsequent study and practical experience. There- 

 fore this feature in the education of the American forester has been 

 practically neglected. 



PRESENT requirements of instruction. 



As long as expert forest entomologists and authentic text-books 

 based on American insects and conditions are not available for giving 

 a complete course in technical and applied forest entomology the 

 requirements of such a course should be limited to instruction in ele- 

 mentary entomology, and in elementary principles of applied forest 

 entomology, which will give the necessary foundation for intelligent 

 observations and utilization of available information as required in 

 future practice. 



CONCLUSION. 



There is conclusive evidence that insects have been in the past, and 

 are now, important factors in the waste and reduction of timber 

 supplies, and will continue to be such in the future (pp. 57-58). 



They attack perfectly healthy trees of all ages and kill them 

 (p. 58). 



They have at times killed a large percentage of the best timber over 

 thousands of square miles of heavily forested lands (pp. 58-60). 



They reduce the value of living timber and that of crude and 

 finished products (pp. 60-G6). 



The accumulated evidence through many years of investigation and 

 observation in the principal forest areas of the entire country by the 

 writer and the field assistants in forest insect investigations furnishes 

 the basis for the following summarized statements and estimate-: 



A large percentage of pine and spruce timber was killed by the 

 southern pine beetle in 1800-189*2 over an area of 75,000 square miles 

 in West Virginia, Maryland, Pennsylvania. Virginia, and North 

 Carolina (p. 58). 



