PREFACE 



This field manual has been prepared to meet the needs of forest 

 rangers, field men, and others entrusted with the protection of 

 forest resources, the prevention of insect damage to timber crops, 

 and the control of forest-insect outbreaks. All sources of informa- 

 tion have been drawn upon to make the compilation as compre- 

 hensive and up-to-date as possible. 



Published bulletins, articles, and records, unpublished reports 

 by field men, and manuals of instruction have been used freely as 

 needed. The text of earlier editions has been revised extensively, 

 to take into account the new insecticides developed during World 

 War II and the tremendous change such chemicals as DDT have 

 made on forest-insect-control procedures. J. M. Miller, J. C. Even- 

 den, R. L. Furniss, and N. D. Wygant furnished material from 

 the different regions of the West. In fact, the entire technical 

 force of the Bureau's western forest-insect laboratories con- 

 tributed material for this publication. J. E. Patterson assisted in 

 preparing the illustrations. 



This manual is restricted to insects found in forests west of 

 the Great Plains, roughly the 100th meridian. Insects of shade and 

 ornamental trees are touched upon only incidentally. A companion 

 volume, "Insect Enemies of Eastern Forests," by F. C. Craighead 

 and eastern workers (37) (Miscellaneous Publication 657) should 

 be consulted for information on eastern forest insects and many 

 others that are Nation-wide in distribution. 



