44 MISC. PUBLICATION- 174, U.S. DEPT. OF AGRICULTURE 



posterior tibia with two apical spurs of which one is short and inconspicuous, 

 their tarsi not thickened. Abdomen about as long as head and thorax, about as 

 broad as thorax, boat shaped or cylindrico-conical, rather strongly reticulately 

 sculptured, the first to fifth tergites einarginate at the middle, the sixth and 

 seventh subequal and each a little longer than the fifth; ovipositor sheaths 

 issuijig from before the apex and barely extending beyond the apex. General 

 color black or purplish black, the head above, mesoscutum, propodeum laterally, 

 and usually the base of abdomen, metallic green ; antennae brownish black, 

 the scape often slightly metallic; all coxae blackish; fore and posterior legs 

 more or less blackish, with their trochanters, apices of femora narrowly, 

 apices of tibiae broadly, and their tarsi yellow ; middle legs mostly yellowish 

 but with their femora and tibiae often more or less dark brown ; wings hyaline ; 

 abdomen usually metallic at base, black beyond; ovipositor sheaths brownish 

 black with the apices usually paler. 



Male. — Length 1.2 to 2 mm. Differs from the female as follows: Distinctly 

 smaller ; antennae similar to that of female, but the pedicel about as long as 

 the three following joints, the first flagellar joint a little broader than long, 

 second as broad as long, third about as broad as long, fourth only slightly 

 longer than broad, fifth subquadrate, sixth and seventh broader than long, 

 eighth about twice as broad as long, club shaped as in the female, with three 

 series of elongate sensoria, without dividing sutures and a little longer than 

 the three preceding joints ; mesoscutum not depressed down the middle, a little 

 more strongly sculptured than in the female, the parapsidal grooves complete 

 but not sharply impressed posteriorly ; scutellum not especially small, sculptured 

 like mesoscutum, as are also the axillae ; propodeum short, without distinct 

 grooves or folds, usually with a very weak median carina, and faintly reticu- 

 lately sculptured ; fore wing about two and one half times as long as broad ; 

 marginal vein a little shorter than submarginal ; stigmal vein nearly half as 

 long as marginal ; fore tibiae as in the female ; middle femora not flattened, 

 their tibiae without a patch of black spines at apex, the tibial spur long but 

 not thickened, the tarsal joints not thickened and without black spines beneath ; 

 abdomen elliptical, usually about as long as thorax, the dorsal segments not 

 emarginate apically. Color bright metallic green or blue-green above, coppery 

 beneath, the abdomen usually blackish above except at base, but with strong 

 coppery tint beneath and on the black dorsal portion ; wings hyaline ; all coxae 

 concolorous with the pleura ; all femora pale yellow ; front tibiae yellow, usually 

 with a black stripe on the outer margin ; middle and hind tibiae black with a 

 narrow band at apex yellow; all tarsi yellowish at base with the apical three 

 or four segments fuscous or blackish. 



More than 300 specimens of this species are in the National Museum 

 collection and have been studied. A part at least of French's original 

 material is included. 



EBVIEW OF LITERATTJKE 



First mention of this species seems to have been made by T. W. 

 Harris in the 1862 edition of his Insects Injurious to Vegetation, in 

 which he gave a short description of what he called a species of 

 Pteromalus which had been reared by Asa Fitch from the jointworm 

 of barley. In 1881 French very briefly described the species, which 

 he named Isosoma allynii, and the following year published a more 

 detailed description of it. French's specimens were reared from 

 wheat stems and were believed by him to be true jointworms. French 

 sent specimens to Riley, who recognized the species as a Ewpelmus 

 and in an article published in 1882 referred the species to its proper 

 genus, at the same time pointing out that it was probably parasitic 

 and not phytophagous. In 1884 French referred to the species as 

 parasitic upon two different species of jointworms, viz Harmolita 

 hordei and H. tritid, and the following year it was first mentioned 

 by Riley as a parasite of the hessian fly. Figures of both male and 

 female were included in Riley's paper. Forbes figured the female 

 and republished French's description of both sexes in his fourteenth 

 report as entomologist of Illinois in 1885. In 1887 Lindeman men- 



