SERPHOID AND CHALCIDOID PARASITES OF THE HESSIAN FLY 133 



and the name Pleurotropis beneftca given to it. Ries recorded the 

 species in 1926 as a parasite of Cephus pygmaeus in New York, and 

 in 1930 Thompson listed it as having been reared from the same 

 host in England. In connection with an exhaustive study of the 

 parasites of C. pygmaeus in England, undertaken with the view of 

 introducing the more effective ones into western Canada for the pur- 

 pose of controlling Cephus ductus Norton in that region, George 

 Salt, of the Imperial Institute of Entomology, in 1931 gave an excel- 

 lent account of P. beneftca in its relationship to C. pygmaeus in Eng- 

 land, including descriptions and figures of adult, larva, and pupa. 

 Smith also mentioned the rearing of P. beneftca from C. pygmaeus 

 material obtained in England and shipped to Canada in connection 

 with the same project. A recent paper by the present author men- 

 tions the occurrence of the species in England and suggests the 

 possibility that it may have been previously described there. Its 

 similarity to several European described forms is discussed, and the 

 characters by which it seems to differ from these are pointed out. 



HOSTS AND LIFE HISTOEY 



While this species is without doubt primarily a parasite of the 

 grain-stem sawflies, Trachelus tabidus and Cephus pygmaeus, it is 

 interesting to record the rearing of a single specimen of it from 

 Phytophaga destructor. According to Myers' unpublished manu- 

 script, this specimen was reared March 31, 1919, from an isolated 

 puparium of the hessian fly collected at Carlisle, Pa. The specimen 

 was identified by the present author after comparison with the type 

 of beneftca, but was later lost while being returned to the collector. 



Little can be said regarding the life history of this species as a 

 parasite of the hessian fly except that it emerges from the host 

 puparium. Salt has definitely established, however, that it is a pri- 

 mary, solitary, internal parasite of Cephus pygmaeus, the parasite 

 larva developing in the body cavity of the host larva, overwintering 

 as a full-grown larva in the cocoon of the host, and emerging as an 

 adult in the spring. No doubt its development as a parasite of the 

 fly is similar. 



DISTRIBUTION 



Pleurotropis beneftca is not known to occur in Europe outside of 

 England. In North America it is at present known only from 

 Maryland, Virginia, Pennsylvania, West Virginia, and New York. 



IMPORTANCE 



The species is at present of no importance as a parasite of the 

 hessian fly. 



PLEUROTROPIS METALLICUS (Nees) 

 (Fig. 31) 



Eulophus metalUcus Nees von Esenbeck, Hymenopterorum ichneumonibus 

 affinium monographiae .... v. 2, 176, 1834. 



Entedon epigonus Walker. Monographia clialcidituni, p. 112, 1839; Forbes, 

 U.S.DeptAgr., Div. Ent., Insect Life 5 : 72, 1892 ; Riley, U.S.Dept.Agr., Div. 

 Ent, Insect Life 6:133. 1893; Howard, U.S.Dept.Agr., Div.Ent., Insect Life 

 6:375, 1893; 7:356, fig. 36. and 414, 1895; Marlatt, U.S.Dept.Agr.. Div. Ent. 

 Circ. (2nd ser. rev.) 12:3. 1895; Marchal, Ann. Soc. Ent. France 66:81, 



