PREFACE V 



have been drawn from various sources, as indicated in the titles, 

 but the authors are under particular obligations to the following 

 persons for the loan of cuts for electrotyping ? Dr. L. O. Howard, 

 Chief of the Bureau of Entomology, United States Department 

 of Agriculture ; Professor F. L. Washburn, State Entomologist of 

 Minnesota; Dr. J. B. Smith, State Entomologist of New Jersey; 

 Dr. V. L. Kellogg, of Leland Stanford Junior University ; Dr. 

 W. E. Britton, State Entomologist of Connecticut ; Dr. E. P. 

 Felt, State Entomologist of New York ; Professor G. W. Herrick, 

 of Cornell University ; Professor C. P. Gillette, Director of the 

 Colorado Agricultural Experiment Station ; P. Blakiston's Son 

 & Co., and D. Appleton and Company. 



The authors are also greatly indebted to the following entomolo- 

 gists for reading portions of the manuscript and criticizing the keys 

 for the identification of insects, which criticisms have added greatly 

 to the accuracy and reliability of the work : Professor Herbert 

 Osborn, Dr. C. T. Brues, Mr. C. W. Johnson, Mr. Nathan Banks, 

 Dr. J, B. Smith, Dr. Harrison G. Dyar, and Dr. A. D. MacGillivray. 



E. DWIGHT SANDERSON 

 C. F. JACKSON 



