VI 



final opinions sometimes diverge strongly from the conclusions indi- 

 cated in the Fernald Catalogue. The present staff of the National Agri- 

 cultural Library of the U.S. Department of Agriculture and the per- 

 sonnel of the former Library of the Bureau of Entomology and Plant 

 Quarantine assisted materially by locating and supplying copies of 

 much of the early, frequently obscure literature that has been examined 

 in the preparation of the list. The late Ruth O. Erieson, translator for 

 the insect identification unit of the Department of Agriculture, trans- 

 lated various foreign language papers. Finally, we extend our sincere 

 appreciation to our colleagues in the Entomology Research Division, 

 and to all who have assisted in any way. 



