1910] Brues, North American Parasitic Hymenoptera IX. 09 



Pezomachus foersteri sp. now 



Female. Length 4 mm. Head twice as broad as thick, subopaque 

 and densely shagreened or punctulate above, the lateral ocelli con- 

 siderably closer to the eye-margin than to the median ocellus. Front 

 fully twice as broad as either eye, scarcely narrowed above by the 

 orbits. Malar space short, the malar line somewhat less than one-half 

 as long as the width of the face. Clypeus short, deeply separated from 

 the face, its lateral fovea? large. Cheeks smooth and polished. Antennae 

 20-21 jointed; basal flagellar joint slightly longer than the second 

 which is three times as long as broad ; fifth twice as long as thick ; 

 those near the apical third of the antenna? quadrate ; apical joint 

 nearly twice as long as the penultimate. Thorax considerably less 

 than three times as long as wide; pronotum (exclusive of the collar) 

 visible from above only as a narrow band ; mesonotum strongly convex ; 

 as long as broad, its surface coarsely shagreened and somewhat shin- 

 ing; scutellmn not at all indicated although there is an elevated ridge 

 behind the mesonotum which extends entirely across the thorax. Meta- 

 thorax strongly gibbous anteriorly, but sharply declivous from before 

 the middle; in front of the carina it shows a number of irregular 

 longitudinal wrinkles, but is smooth on the posterior slope. Trans- 

 verse carina complete, very sinuous medially and continuing to the 

 posterior angles of the metathorax where it meets a short oblique 

 carina, forming a triangular areola above each coxa. Petiole of abdo- 

 men long and evenly dilated toward the base ; three times as long as 

 broad at tip and one third as broad at base as at tip; spiracular tuber- 

 cles moderately large, angular: postpetiole longitudinally aciculated. 

 Body of abdomen broad, the second and third segments subequal in 

 length, third more shining; abdominal hairs sparsely placed. Oviposi- 

 tor half as long as the petiole. Legs rather slender ; longer spur of hind 

 tibia one third as long as the metatarsus which is twice as long as the 

 second tarsal joint. Head, thorax, legs, first segment of abdomen, and 

 antennas except their darker tips, reddish ferruginous; abdomen black, 

 the petiole and second segment, obscurely yellowish at their tips. 

 Austin, Texas ; April and May. 



Structurally this species is closely related to P. obesns. al- 

 though it is much smaller and lighter colored. The sculpture of 

 the head above and the mesonotum is finer ; the scutellum is not 

 distinctly separated by a transverse furrow as in the former spe- 

 cies ; and the petiole is less strongly dilated behind the spiracles. 



