Subfamily Metopiinae 



The ichneumon flies which are the subject of this paper are 

 stout-legged species, with a stout cylindric body, clypeus not separated 

 from face by a groove, scape ovoid (about 1.2 to 1.7 as long as wide), 

 spiracles of first abdominal segment at or in front of its midlength, 

 areolet absent or of the triangular type (though seldom really tri- 

 angular), ovipositor not protruding beyond end of abdomen, and 

 usually the second trochanter of the front and middle legs fused with 

 their femora. Their clypeus and face together form a bulging, convex 

 surface except in the genus Metopius, in which the face has a large, 

 flat or concave, escutcheon-shaped area. The upper margin of the 

 face is produced into a triangular process which extends between or 

 over the bases of the antennal sockets. This latter character occurs, 

 with variations, throughout the subfamily and is its most distinctive 

 single characteristic. The general habitus of the subfamily is illus- 

 trated by the figures of the various genera (figs. 163 to 177). 



This subfamily stood taxonomically for many years as three 

 separate tribes in the subfamily Tryphoninae : the Metopiini, the 

 Tylocomnini (or Trachydermatini) , and the Exochini. Several 

 authors had noted points of similarity between these tribes, and in 

 1945 they were grouped together as a single subfamily, separate from 

 the Tryphoninae (Townes, 1945, Mem. Amer. Ent. Soc, vol. 11, 

 pp. 570-588). A few genera which have been assigned to the Meto- 

 piinae or to the tribes united to form the subfamily, do not fit the 

 above definition of the subfamily. These, which we believe are prop- 

 erly assigned elsewhere, are discussed below. 



Hyperacmus disagrees with the Metopiinae in lacking the inter- 

 antennal process of the frons; in having a sharp groove between the 

 clypeus and face, second trochanter of front and middle legs distinct, 

 a different style of carination on propodeum ; and in some other, more 

 subtle, characters. Townes (1945, Mem. Amer. Ent. Soc. vol. 11, 

 p. 545) has referred Hyperacmus to the Plectiscinae, next to Microleptes, 

 which appears to be its proper position. The genus Ibornia, referred 

 by its author to the Metopiinae, is a member of the Tryphonini, near 

 Ctenochira. 



Thibetoides is a genus of Tryphoninae in the strict sense. It has 

 recently been redescribed and figured by the authors (1949, Trans. 

 Ent. Soc. Amer. vol. 52, p. 418). Catocentrus is a synonym of Mono- 

 blastus, a genus of the Tryphoninae. The genotype of Catocentrus 



s 



