ACKNOWLEDGMENTS 



Of the figures illustrating this work, the following 

 were drawn for me by Mr. John A. Grossbeck, my as- 

 sistant, from originals or modified from published 

 sources: i, 4, 5, 6, 7, 8, 10, 11, 13, 18, 19, 20, 22, 24, 

 34, 41, 61, 64, 65, 66, 67, 68, 70, 71, 80, 81, 87, 89, 92, 

 93. 94, 95- 96, 104, 107. 



From the publications of the Entomological Division 

 of the U. S. Department of Agriculture the following 

 were obtained, either as electrotypes or as copies from 

 the prints: 9, 49, 63, 77, 91, 98, 100, loi, 103, no, 112, 



113- 



From the New Jersey Agricultural College Experi- 

 ment Station I obtained blocks for figures 48 and 99. 



The other blocks are by courtesy of the J. B. Lip- 

 pincott Company from my "Economic Entomology," 

 where their original source is stated; but a number of 

 them have been somewhat reduced in size. 



