98 Annals Entomolgoical Society of America [Vol. IX, 



of the hairless discal streak on the primaries, and this is obscure 

 in the species about to be described." 



We were quite surprised to find last July that an Aphelinine 

 was emerging from Hessian Fly puparia. These have been 

 determined by Mr. A. B. Gahan, of the Bureau of Entomology, 

 as Paraphelinus speciosissimus Girault. As will be noted from 

 the above quotation, it requires only a slight elaboration of 

 Dr. Howard's theory to include as a host for this genus the 

 Hessian Fly, whose puparia resemble superficially the eggs of 

 an Orthopterous insect and are embedded in the stems of wheat. 



The original specimens upon which the present data are 

 based were secured from wheat stubbles collected by Mr. P. R. 

 Myers of the Bureau of Entomology. The puparia were 

 removed from these stubbles and placed in cages containing 

 nothing else. Adults reared from these puparia were used by 

 the writer in experimentally parasitizing other puparia known 

 to be absolutely free from any parasites, and three more suc- 

 cessive generations have thus been reared from the original 

 parents, The rearing has been conducted at Hagerstown, Md., 

 and all data here given apply to laboratory conditions at 

 that point. 



DISTRIBUTION. 



Girault's original specimen was collected on a granary win- 

 dow at Urbana, 111. In spite of the fact that we have reared 

 large numbers of Hessian Fly puparia from various points in 

 Pennsylvania, Maryland, Virginia and West Virginia, we have 

 thus far secured this parasite only from the following six local- 

 ities in central Pennsylvania: Linden, Montoursville, Muncy, 

 Montgomery, Northumberland, and Andersonburg. The first 

 five localities are in two adjoining counties along the Susque- 

 hanna River, where a serious outbreak of Hessian Fly occurred. 

 The last locality is about fifty miles southwest from Northum- 

 berland, and here only about 31% of the stubbles were infested 

 by the Hessian Fly. Out of a total of 3165 puparia secured 

 from all of these localities, only 17, or a little more than .005%, 

 were parasitized by this Chalcidoid. Some fields in each 

 locality yielded none of these parasites, while in the other fields 

 the percentage of parasitization varied from 0.14% at Ander- 

 sonburg to 3.2% in one field at Muncy. In the latter field 

 Mr. Myers estimated that 65% of the stubbles were fly-infested. 



