AN ILLUSTRATED SYNOPSIS OF THE PUP ARIA OF 100 

 MUSCOID FLIES (DIPTERA). 



By Charles T. Greene, 

 Of the Bureau of Entomology, United States Department of Agriculture. 



INTRODUCTION. 



Those who have ever been engaged in the interesting pursuit of 

 rearing parasitic insects doubtless have been impressed with the 

 great desirability of having at hand some means of determining 

 before the issuance of the adult insect the probable identity of the 

 species under observation. This advance information often would 

 not only render possible the collection of additional valuable material 

 of the same kind but enable the observer in many cases to know 

 months in advance of the issue of the adult parasite the species 

 with which he was dealing. All students of the Muscoidean flies 

 who have attempted to rear the larvae of this group, as well as 

 other students of insect biology engaged in the study of the parasi- 

 tology of any insect, have experienced the pangs of disappointment 

 caused by the death of a unique specimen after pupation has occurred. 

 In most such cases in the past this has resulted in the complete loss 

 of the notes accumulated previous to the death of the parasite, but 

 it is believed that by using the means proposed in this brief pre- 

 liminary paper such losses may largely be overcome in the future, at 

 least where the species treated in this paper are involved. 



Several years ago, while engaged in studies of the Muscoidean 

 flies in relation to their hosts, Mr. W. R. Walton became greatly 

 impressed with the great variety and seeming constancy of the char- 

 acters presented by the puparia of the members of this vast complex, 

 which came under his notice.. This suggested the possible construc- 

 tion of an illustrated synopsis, based on puparial characters, for the 

 determination of some of the forms most commonly reared in the 

 study of economic insects. With this in view he began to accumulate 

 material and prepare drawings as opportunity offered. After 32 

 drawings had been made, in 1916, the assignment of administrative 

 work compelled the abandonment of these plans, and all of the ma- 

 terial, drawings, and notes were turned over to the present author, 

 with the idea that he might proceed with them as he saw fit. The 



No. 2405.-PROCEEDINQS U. S. NATIONAL MUSEUM, VOL. 60, ART. !0. 



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