INTRODUCTION. 



The following catalogue of the exhibit of economic entomology 

 made by the Division of Entomology, U. S. Department of Agricul- 

 ture, at the Louisiana Purchase Exposition, has been prepared with a 

 view of increasing the usefulness of the exhibit from an economic and 

 educational standpoint, and it is intended to supplement the exhibit by 

 giving bibliographical references which will enable persons interested 

 readily to gain information additional to that combed by the label. 

 The general supervision of the preparation of the exhibit itself was 

 placed by the writer in the hands of Mr. August Busck, assistant in 

 the Division of Entomology, and in this laborious task he has had the 

 valuable expert assistance of Mr. F. C. Pratt and Mr. E. S. G. Titus, 

 also assistants in the Division. The catalogue itself has been compiled 

 by Messrs. Titus and Pratt. The present catalogue does not include 

 a consideration of the exhibit of insects injurious to forest trees, which 

 will be published as a separate pamphlet on account of the desirability 

 of independent distribution of this portion of the catalogue to persons 

 interested in forestry matters. 



The Division of Entomology has been represented at many interna- 

 tional expositions, its first serious attempt to represent its work in 

 this way having been made at the New Orleans Cotton Exposition of 

 1884. It was represented by large collections at the subsequent 

 World's Fair at Chicago, at the International Exposition at Paris, at 

 the expositions at Atlanta, Nashville, Omaha, Buffalo, and Charleston. 

 The present exhibit, however, is, in many respects, a more interesting 

 one than any of its predecessors. An effort has been made to illustrate 

 in all of their stages the principal insects injurious to North American 

 crops'. Further attempts have been made to show the economic rela- 

 tions of insects in other respects and, on account of the great current 

 interest in the subject of the spread of disease by insects, more atten- 

 tion has been paid to this subject than ever before. Special cases 

 illustrating insects of the greatest immediate popular interest have 

 been prepared, and a series of models of the most prominent economic 

 insects of the day is shown. An effort has been made to introduce a 

 novel feature in this exhibit, namely, living insects feeding under as 

 natural conditions as possible, which will probably prove of quite as 

 great interest to visitors as the illustrative cases of dried specimens. 



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