A MONOGRAPHIC REVISION OF THE TWISTED WINGED 

 INSECTS COMPRISING THE ORDER STREPSIPTERA 

 KIRBY. 



By W. Dwight Pierce, 



Bureau of Entomology, U. 8. Department of Agriculture. 



INTRODUCTION. 



The writer presents, in monographic form, a grouping of the most 

 important facts recorded concerning the insects of the order Strepsip- 

 tera Kirby, often known as the coleopterous family Stylopidse Kirby, 

 together with considerable new material bearing upon the classifica- 

 tion, structure, and habits of the order. The manuscript has been 

 completed up to March 1, 1909. 



The importance of a more intensive and extensive study of the 

 Strepsiptera is made manifest by a perusal of the large list of host 

 species, among which are already recorded at least twenty-eight inju- 

 rious species. The group is entirely composed of parasitic insects, 

 and the insidious nature of their attack, which in few cases inconven- 

 iences the host, renders detection difficult. It is desired that this 

 article may be the forerunner of much valuable information concern- 

 ing them. 



It is of great importance for interested students throughout the 

 world to make themselves known to each other, in order that together 

 they may hasten the understanding of these parasites, and also that 

 in future publications the scattered notes, published and unpublished, 

 from all lands may be brought together to form a more complete 

 knowledge of their biology and structure. 



ACKNOWLEDGMENTS. 



The writer's personal acknowledgments are due to the U. S. 

 National Museum and its entomological corps for their courtesy in 

 according all possible facilities for the study of material there depos- 

 ited and in accepting for publication this article; to Dr. L. O. Howard 

 and Mr. W. D. Hunter for their assistance in facilitating the work; 

 to Mr. E. A. Schwarz and to the late Dr. W. H. Ashmead for valuable 



