CLASSIFICATION OF THE ICHNEUMON FLIES, OR THE 

 SUPERFAMILY ICHNEUMONOIDEA. 



By William H. Ashmead, 



Assistant Curator, Division of Insects. 



The characters common to genera give those of the higher groups ; the orders and their common characters 

 combine to form those of the classes. It depends, therefore, upon every classifier hoiv far he will proceed 

 in separation and subdivision. Indeed, much difference of opinion exists upon the determination of the 

 groups between the species arid the order, whence have arisen the several definitions of subgenus, genus, 

 and tribe. In fact, opinions will never harmonize upon the claims of genera, because no universal prin- 

 ciple for the structure of genera in any artificial subdivision can be given. This principle is in itself 

 exceedingly capricious, and if one maintains thus far a gemis extends, and another thus far, both are 

 certainly right, if only every group, ivhich they distinguish as genera, is distinguished by similar and 

 exclusive characters. Burmeister. 



The pertinency of thi.s quotation from one of the great masters of 

 the science of entomology will be better understood and appreciated 

 when the body of this work is examined and it is found that no less 

 than eleven hundred and forty gtntra^ or more, have been recognized 

 and tabulated, although when Burmeister penned the above lines, in 

 1835, the Ichneumonoidea contained only about one hundred and nine 

 (jenera. If we go back to the early da}^s of Burmeister, we tind, 

 too, that authorities differed as to the value and utility of some of 

 these genera, just as they differ to-day. In ni}' tables, therefore, there 

 will be found man}- genera which by some eminent living hymenop- 

 terologists are thought to be of no value, but which the writer, on 

 the contrary, holds to be good and distinct — a difference of opinion 

 that time alone can settle. 



Ver}' few persons have given any attention to these insects, and the 

 necessity for these line subgeneric and tribal divisions is evidently 

 apparent to only a few active workers. The great majority of the 

 workers in other groups seem totally ignorant of this vast complex, or 

 at least have no conception of its immensity or the difficulties encoun- 

 tered in studying and identifying material belonging to it derived 

 from different parts of the world. 



The writer has now been studying the Hymenoptera for twenty-five 

 years, and much of this time has been devoted specially to studies in 



Proceedings U. S. National Museum, Vol. XXIII— No. 1206. 

 Proc. N. M., vol. xxiii 1 i 



