NO. 2195. 



MJW iSPECIES OF HYMENOPTERA—ROUWER. 153 



sheath is parallel-sided, not convex above and below, gradually round- 

 ing to a point at apex. 



/'>ma?e.-— Length, 4.5 mm. Anterior margin of the clypeus 

 broadly, arcuately emarginate, the surface shining, very sparsely 

 punctured; the supraclypeal area flat, rectangular in outline; middle 

 fovea transverse, deep; frontal fovea deep, punctiform, above the 

 middle fovea; frontal crest well developed, broken in the middle; 

 antennal foveae poorly defined; ocellar basin U-shaped, opened be- 

 low; a very faint, shallow depression in front of the anterior ocellus; 

 postocellar line subequal with the ocellocular line ; postocellar furrow 

 wanting; postocellar area subconvex, about two and one-half times 

 as wide as the cephalcaudad length; third antennal joint one and 

 one-third times as long as the fourth; thorax shining; stigma 

 slightly tapering to the transverse radius, then sharply oblique to 

 the apex; the second and third transverse cubiti subequal in length; 

 the transverse radius in the apical third of the cell; second joint of 

 the hind tarsi much longer than the third, almost as long as the 

 third and fourth combined ; inner tooth of the claw shorter than the 

 outer; sheath approximately parallel-sided; the lower side gradu- 

 ally rounds to the acute upper apex. Black; the four anterior legs 

 below the tips of the femora, the basal half of the posterior tibiae, 

 and the basal third of the posterior basitarsus white ; wings hyaline, 

 faintly dusky ; venation black. 



Type-locality.— E^st Falls Church, Virginia. Described from two 

 females recorded under Bureau of Entomology No. Hopk. U. S. 

 11307a, material collected as larvae July 13, 1913, by William Middle- 

 ton. Adults emerging August 5 (type) and 13, 1913. 

 Type.— Cat. No. 15486, U.S.N.M. 



The larva of this species is a typical greenish- white Eriocampoides 

 larva, feeding on the ventral surface of the leaves of Castanea den- 

 tata. The head is pale ferruginous. 



Genus PERICLISTA Konow. 

 Syn. : Isodyctium Ashmead. 

 Ashmead separated his genus Isodyctium from Periclista Konow 

 by the sessile anal cell in the hind wings. This character is not of 

 specific importance, it is subject to both individual and specific varia- 

 tion. In diluta Cresson there is a variation in seven female speci- 

 mens from the same rearing of larvae, from sessile to distinctly petio- 

 iate. In some species (lineolata) the petiole is long; in others {car- 

 yicola) it is short, while in still others it is of intermediate length. 

 From the standpoint of tlie genotypes no difference could be found 

 except the relative length of the petiole of the hind anal cell. The 

 genus Isodyctium is therefore considered as synonymous with Peri- 

 clista. 



