ART. 16 NEW ICHNEUMON-FLIES — MUESBBECK 15 



apparently overlooked the distinct circuliform mouth opening and 

 was unduly influenced by the unusually stout and dentate posterior 

 femora. 



E. manilae Ashmead is clearly congeneric with the genotype. 



Subfamily VIPIINAE 

 MICROBRACON RHYACIONIAE, new species 



Kuns to couplet 37 in my key to the North American species of 

 MicTobracon ^^ and is most similar to fini Muesebeck, but differs from 

 that species especiallj^ in the mostly testaceous abdomen, the gener- 

 ally darker legs, the somewhat longer ovipositor sheaths, and the 

 relatively narrower head. 



Female. — Length, 3.8 mm. Head distinctly narrower than thorax, 

 moderately thick antero-posteriorly, smooth and shining; face with 

 a little faint punctation; diameter of mouth opening considerably 

 greater than distance from the opening to the eyes; antennae of 

 type 33-segmented, slender, tapering slightly apically; first flagellar 

 segment about twice as long as broad, the following a little shorter 

 but all distinctly longer than broad. Thorax stout, smooth, and 

 polished, notauli lined with long delicate hairs ; propodeum polished, 

 without oblique rugae behind ; pleura smooth ; second abscissa of 

 radius about twice the first; the third about as long as the first 

 and second abscissae combined. Abdomen longer than thorax, 

 mostly polished; first tergite very weakly roughened, the grooved 

 lines setting off the large median triangular plate foveolate; second 

 tergite strongly transverse, its posterior margin arcuate, the sur- 

 face of the tergite mostly smooth, with only a little weak sculpture 

 medially; suturiform articulation rather broad; third and follow- 

 ing tergites polished, the sutures very fine ; ovipositor sheaths slender, 

 a little longer than the abdomen. Head and thorax entirely black; 

 all legs black or blackish ; wings weakly infumated ; abdomen tes- 

 taceous, with a median blackish area on first tergite and very small 

 blackish median patches on third, fourth, and fifth tergites. 



Male. — In essentials similar to the female; antennae 32-segmented ; 

 apical abdominal tergites almost entirely black. 



r?//?e.— U.S.N.M. No. 42875, from Pactola, S. Dak. 



Host. — Rhyacionia on western yellow pine {Pinus po7iderosa.) 



Eight females and two males reared in August, 1926, by L. G. 

 Baumhofer under Hopkins U. S. No. 17511. 



Female paratypes present slight variations in the color of the 

 abdomen, which varies from entirely testaceous to rather broadly 

 black medially on third and following tergites. There is also a 

 slight variation in the number of antennal segments. 



" Proc. U. S. Nat. Mus., vol. 67, p. 12, 1925. 



