PROC. ENT. SOC. WASH., VOL. 23, NO. 5, MAY, 1921 119 



margin set off by acarina from the anteriordeclivous portion which is sculptured; 

 mesoscutum strongly punctate, the parapsidal grooves complete and each 

 terminating posteriorly in a large foveiform depression, the surface within the 

 depression as strongly sculptured as the remainder of mesoscutum; scutellum 

 much longer than broad, sculptured like the mesoscutum, except that on the 

 anterior half of scutellum the punctures are somewhat smaller; axillae above 

 sculptured like mesoscutum, below much more finely punctate; propodeum 

 polished, the median carina forked a little behind the middle, the lateral folds 

 straight and well developed, spiracular furrows deep; posterior lateral argles 

 of the propodeum produced into a short triangular tooth-like process just above 

 the attachment of the hind coxae; mesosternum nearly smooth, the median 

 groove terminating anteriorly in a foveiform enlargement; abdomen not quite 

 as long as the head and thorax, pointed ovate; petiole large, broader than long, 

 opaque, carinately margined laterally, above and below, and with the anterior 

 margin produced dorsally into a short flange which overlaps the posterior end 

 of the propodeum; second segment comprising about one-third the length of the 

 abdomen, smooth basally, the apical half weakly reticulated; third and following 

 tergites all finely sculptured, subopaque, and distinctly though sparsely hairy; 

 third tergite about one-third as long as the second; fourth to sixth subequai and 

 each about two-thirds as long as the third; seventh approximately equal to the 

 third; ovipositor concealed; submarginal vein of the forewing distinctly less than 

 half as long as the very long marginal, with two or three upright black bristles 

 above; proximal end of the marginal vein with a similar bristle, also; post- 

 marginal and stigmnl veins short and subequai. General color bright bluish- 

 green: head darker than the thorax with the occiput black, and the face blackish, 

 except that the area just below the insertion of antennae is coppery and the 

 triangular area above the transverse groove is slightly more bluish; antennae 

 entirely metallic black; legs concolorous with the thorax, their tarsi brownish 

 black; second tergite bright blue-green; the petiole and segments beyond the 

 second brownish-black; wings hyaline, the venation dark brown. 



Male. Length 2.2 mm. Antennae 10-jointed, scape slightly and nearly 

 uniformly thickened, about four times as long as thick; pedicel not much longer 

 than thick; three ring-joints transverse; flagellum longer but no more hairy than 

 in the female; first funicle joint four times, second two and one-half times, and 

 the third slightly more than twice as long as thick; fourth joint barely twice as 

 long as thick; club solid, about as long as the second funicle joint and terminating 

 in a distinct spine; abdomen short, the segments beyond the fourth retracted ami 

 mostly concealed; petiole longer than broad, almost as long as the hind coxai-, 

 and without distinct margn.al carinae. Otherwise like the female except that 

 the head is for the most part concolorous with the thorax, only the occiput ami 

 a transverse patch on the vertex embracing the posterior ocelli being black. 



Type-locality. Mount Holly Springs, Pennsylvania. 



Type. Cat. No. 24,166, U/S. Nat. Mus. 



Host. Trachelus tabidus Fabricius. 



Eleven females and four males reared by W. R. McConnell, 

 April 13 to 19, 1919, from hibernating prepupal larva of the 

 black grain-stem sawfly and recorded in the Bureau of Ento- 

 mology under Webster No. 18,700; one female paratype reared 



