PREFACE 



During recent years there has been increasing demand for 

 short courses in elementary entomology. For several years past 

 the authors have been endeavoring to present such courses to 

 their students, but have encountered the difficulty that no textbook 

 was available which met their needs. This book is, therefore, the 

 authors' effort to furnish such a text for beginners, and if it is 

 found useful to them and to the increasing number of teachers 

 who are endeavoring to instruct them in the subject, the authors 

 will feel well repaid. The work is confessedly very largely a com- 

 pilation from the works of others (as, indeed, any such work must 

 be), and it is obvious that many errors and defects may have been 

 overlooked, although the authors have spared no pains to eliminate 

 them. To those who observe such shortcomings, or who may be 

 able to offer suggestions for the improvement of the book when 

 revised, the authors will be under great obligation. 



It was originally intended to include several chapters treating of 

 the various insect pests affecting crops and domestic animals, but 

 it was found that such a work would be too cumbersome ; indeed, 

 it is usually not possible to cover both elementary and economic 

 entomology in a single course. The economic side of the subject 

 has, however, been made the dominant note in the following pages, 

 and the forms discussed are mostly those of economic importance. 

 There is a popular belief, often held by young agricultural stu- 

 dents, that the chief subject matter of a course in entomology 

 should be a discussion of the common injurious insects. Expe- 

 rience has shown that such an idea is fallacious, and that, from the 

 standpoint of practical utility as well as from that of general cul- 

 ture, a knowledge of the structure, habits, and classes of insects 

 in general is much the more important phase of entomology for 

 academic study. Economic entomology is important and should 



