136 MISC. PUBLICATION 17 4, U.S. DEPT. OF AGRICULTURE 



spiracular sulci deep and nearly straight, spiracles small and round ; mesopleura 

 mostly reticulated but with a smooth area medially and another posteriorly; 

 mesosternum mostly smooth ; metapleurum very small, nearly smooth, and with 

 a short projecting tooth or tubercle posteriorly. Legs slender ; tarsi 4-jointed ; 

 hind coxae weakly reticulated. Wings fully developed, the fore wing extending 

 beyond apex of abdomen ; submarginal vein with two erect bristles dorsally : 

 marginal vein more than twice the submarginal, stigmal and postmarginal 

 veins subequal, both short; base of wing mostly bare. Abdomen ovate, about 

 as long as thorax, distinctly petiolate ; petiole about as long as broad, finely 

 and closely punctate, the anterior dorsal margin produced slightly forward so 

 that it overlaps the apex of propodeum ; first tergite (not counting the petiole) 

 comprising approximately one third to one half the total length of abdomen, 

 perfectly smooth, and highly polished ; following tergites distinctly reticulated 

 basally, smooth at apex, the sixth and seventh almost entirely sculptured ; 

 ovipositor not exserted. General color bright green or bluish green, the frons 

 and face with a bronzy cast and the occiput dull black; antennae black, the 

 scape slightly metallic ; legs all metallic green, their tarsi black or blackish ; 

 petiole black; first tergite bright metallic green, following tergites and the 

 .sternites bronzy black ; wings hyaline, venation blackish. 



Male. — Length 1.2 to 1.6 mm. Antennae 10-jointed, much longer than in the 

 female; scape slightly and nearly uniformly thickened throughout its length, 

 about four times as long as thick, reticulated on its inner side, smooth on its 

 outer side ; pedicel about one and one half times as long as thick ; three trans- 

 verse ring joints (distinct only when slide-mounted) ; flagellum not thicker at 

 apex than at base. 5-jointed, the joints subequal and rather distinctly sep- 

 arated, the first four each approximately three times as long as thick, the 

 apical joint elongate oval and ending in a distinct process or spine which 

 is not over one fourth the length of body of segment ; the whole flagellum 

 moderately hairy, the joints without any elongate sensoria. Abdomen short, 

 the apical segments usually retracted, the abdomen thus appearing squarely 

 truncate at apex; petiole a little longer than broad, opaquely punctate; first 

 segment beyond the petiole smooth and polished. Otherwise like the female 

 except that the face and frons are not tinted with bronze. 



Described from the following material: 6 specimens bearing the 

 label Semiotellus nigripes Lindeman in Lindeman's own handwrit- 

 ing, received by Riley or Howard from the author of the species 

 and probably constituting a part of the type material; 14 mounted 

 and many unmounted specimens received in 1890, 10 received in 

 1891, and 5 others in 1894, all reared from puparia of the hessian 

 fly collected by Fred Enock in England; 2 specimens reared from 

 the % by W. D. Taylor at Daleally, Errol, New Brunswick; and 66 

 specimens reared from the fly in various localities in the eastern part 

 of the United States. 



REVIEW OF LITERATURE 



Nees described Eulophus nietallicus in 1834 from specimens of 

 both sexes taken on oak at Sickershausen, German}^. Five years 

 later Walker described Entedon epigonus from specimens collected 

 near London, England, on the Isle of Jersey, and in Ireland. In 

 1848 he synonymized his species w T ith metatlicus Nees, which he 

 transferred to the genus Entedon. In 1887 Lindeman characterized 

 as Semiotellus nigripes a parasite reared by him from the hessian 

 fly in Russia, and Miss Ormerod, who was at the time investigating 

 the recent appearance of the hessian fly in England, reared parasites 

 from it in that country w<hich w r ere identified for her by Lindeman 

 as S. nigripes. The occurrence of this parasite in England was 

 confirmed by Riley, and also by Enock, the following year. In 1891 

 Enock wrote of having sent to Riley a large number of fly puparia 

 containing S. nigripes with a view to the establishment of the para- 



