I'ROC. ENT. SOC. WASH., VOL. 23, N'O. 5, MAY, 1921 113 



REMARKS ON THE GENUS PLEUROTROPIS WITH DES( RIPTION 



OF A PARASITE OF TRACHELUS TABIDUS FABRIC IIS. 



i H YMENOPTERA : (H ALCIDOIDE A. j 



Bv A. B. GAHA.V, Bureau of Entomology. 



The occurrence of the exotic sawfly, Trachelus tabidus 

 Fahricius, in America as a possibly serious pest of wheat was 

 brought to light during the summer of 1918. A paper by the 

 writer treating of this sawfly has already been published by the 

 U. S. Department of Agriculture. 1 Mention is made in this 

 article of the rearing by Mr. \V. R. McConnell of a parasite 

 belonging to the genus Pleurotropis and apparently representing 

 an undescribed species. 



In view of the foreign origin of the host it is natural to suspect, 

 though the conclusion does not necessarily follow, that the para- 

 site too is exotic. It has proved impossible to reconcile the 

 insect with the description of any exotic form, however, and as it 

 does not conform to any described American species it seems 

 desirable to describe it. 



In the process of identifying this species the writer was led into 

 making a more or less careful study of the characters, especially 

 those of the antennae, appertaining to the genus Pleurotropis. 

 The results of this study are discussed herewith. 



Family EULOPHIDAE. 



Subfamily Entedoninae. 



Genus PLEUROTROPIS. 



Pleurotropis Foerster, Hymen. Stud. II, 1856, p. 78. 

 Pseudacriasoides Girault, Descriptiones Stellarum Novarum, 1917, p. 9. 

 Epipleurotropis Girault, Descriptiones Hymenopterorum Chalcidoidicarum 

 cum Observationibus, 1917, p. 7. 



The two genera listed as synonyms are based upon characters 

 which, after examination of the types, I can not accept as 

 generic. 



Pseudacriasoides has as type Pleurotropis utahensis Crawford. 

 The generic description by Girault is as follows: "Antenna 

 9-jointed, three ring-joints, the club 2-jointed; male antenna 

 1 ((.jointed, three ring-joints, the club 2-jointed, the scape 

 dilated. Scutellum with a median sulcus at base. Otherwise 

 like Pleurotropis.'" 



Pleurotropis utahensis' 1 - was described from four female and 

 six male specimens of which the holotype was reared at Salt 

 Lake Cir\ , I tah, from Agromyza parvicornis mining the leaves 

 of corn, while the allotype and all paratypes were reared from 



Bul. 834, U. S. Dept. Agric., 1920, 18 pp. 

 2 Proc. U. S. Nat. Mus., vol. 45, 1913, p. 316. 



