SEEPHOID AND CHALCIDOID PARASITES OF THE HESSIAN FLY 69 



abdomen pointed ovate, about as long as thorax, weakly convex dorsally, the 

 first and second tergites combined constituting about half its length, the first 

 tergite equal to about twice the second. Head and thorax brassy-green, the 

 clypeal region, under side of thorax, and the propodeum more or less tinged 

 with bluish ; antennal pedicel and flagellum blackish ; scape reddish testaceous, 

 with the apex fuscous ; all coxae metallic like the thorax ; remainder of legs 

 reddish testaceous, the apical tarsal joint dark brown ; abdomen black ; 

 wings hyaline, the fore wing with a large subcircular, not very distinct fuscous 

 cloud in the middle. 



Male. — Length 1.7 mm. Flagellum cylindrical, the club not or scarcely thick- 

 ened, funicle joints each approximately one and one half times as long as broad 

 and subequal ; ocellocular line a little shorter than the postocellar ; transverse 

 constriction at base of propodeal neck not so deep as in the female; abdomen 

 shorter than the thorax, ovate, not pointed at apex ; median tibiae weakly 

 clavate and slightly compressed towards apex. Head and thorax lightly 

 metallic blue-green ; scape pale, flagellum dark brown or fuscous ; legs includ- 

 ing all coxae pale testaceous, the middle tibiae except narrow base black; 

 apical tarsal joint blackish ; wings hyaline, without a fuscous spot. Otherwise 

 like the female. 



The type material consisted of 5 females and 35 males reared from 

 Phytophaga destructor by W. E. McConnell and P. E. Myers at 

 Hanover and Carlisle, Pa. Eight additional specimens are now in 

 the National Museum collection. 



REVIEW OF LITERATURE 



The species was first reared from puparia of the hessian fly by 

 P. E. Myers at Hanover, Pa., in 1917 and described 5 years later by 

 the present author. Myers subsequently (in 1924) published a short 

 paper on the biology and morphology of the early stages, and more 

 recently (1931) Hill and Smith jointly have published additional 

 facts regarding the same subjects. 



HOSTS AND LIFE HISTORY 



The species is normally a primary, solitary, external parasite of 

 hessian-fly larvae and pupae, but it may develop as a secondary 

 parasite through Platyg aster zosine Walker, and possibly other fly 

 parasites, according to Myers. It is said to attack both the spring 

 and the fall generations of the fly. The egg is placed upon the host 

 within its puparium, and development may take place upon either 

 the larva or the pupa, according to Hill and Smith, who also state 

 that five instars occur. The parasite emerges as an adult from the 

 fly puparium. 



DISTRIBUTION 



The known distribution of this species is confined to Pennsylvania 

 and Maryland and the Province of Ontario, Canada. 



The type material was from Hanover and Carlisle, Pa. Specimens 

 have also been taken by McConnell and Myers at Andersonburg, 

 Gettysburg, Montoursville, Perkasie, and Sellersville, Pa., and at 

 Hagerstown, Md. One specimen in the National Museum collection 

 was reared by H. D. Smith from a puparium taken at Mount Holly 

 Springs, Pa.^and another received from J. McDunnough was reared 

 from a puparium taken at an unknown locality in Ontario, Canada. 



IMPORTANCE 



Myers recorded a maximum of 0.85 percent of the spring genera- 

 tion and 1.5 percent of the fall generation of the fly attacked by this 



