PREFACE. 



Tfiis book is designed to meet the needs of students and 

 others who wish to learn something of insect Hfe especially 

 in relation to farm crops and livestock. The author assumes 

 that the students who read it will have had some training 

 in general biology and will have the guidance of teachers 

 familiar with the subject in connection with adequate labor- 

 atory facilities and opportunities for field studies. The 

 details of laboratory and field studies have not been included 

 since these are easily supplied by the teacher. For those 

 making individual studies there are many available books 

 covering the technic of entomological work. A glossary 

 has been included which covers the subject as presented in 

 these pages and in most of the reports and bulletins that are 

 likely to be consulted by the average student. 



In order to make the scope of the book adequate it has 

 been necessary to condense the matter to the most essential 

 details, and to omit much that has value but which is not 

 absolutely indispensable to the presentation of the important 

 principles that concern the practice of economic entomology. 



The author acknowledges his indebtedness to many 

 sources of information which are too numerous to mention 

 individually, but he is especially indebted to Dr. Howard, 

 of the Bureau of Entomology, for the privilege of using the 

 illustrations secured from his office and for suggestions; to 



