ICHNEUMON-FLIES — GELINAE: MESOSTENINI 21 



for Mesostenina, they are included in the key to the Nearctic genera of that 



subtribe, at couplets 1 and 28.) 1. Baryceratina (p. 21) 



Upper valve of ovipositor without a series of teeth or transverse ridges be- 

 tween nodus and apex, or rarely (as in some species of Gambrus and Apsilops) 

 with a few weak teeth (but not ridges) just beyond the nodus. 



2. Mesostenina (p. 32) 

 6. Females only; apex of clypeus weakly convex; ovipositor extending conspic- 

 uously beyond apex of abdomen; fourth tarsal segment bilobed at apex (see 

 from below) ... 2. Mesostenina (some females of A gr other elites) (p. 32) 

 Females (and males?); apex of clypeus truncate or concave; ovipositor not 

 extending beyond apex of abdomen; fourth tarsal segment not bilobed at 

 apex .... 5. Sphecophagina (some specimens of Sphecophaga) (p. 522) 



1. Subtribe Baryceratina 



Clypeus usually moderately small, moderately convex, its apical 

 edge truncate, often with a weak median angle or pair of points; man- 

 dible 2.0 to 2.5 as long as it is wide at the middle, its upper tooth 

 somewhat larger than the lower tooth; fiagellum rather thick and 

 short, in female the apical half often a little thicker than basal half; 

 tip of last segment of female fiagellum narrowed to a rounded point; 

 thorax usually stout, the mesoscutum often broad and weakly convex, 

 the propodeum usually short; propodeal spiracle elliptic or elongate; 

 front tibia of female not mflated; fourth tarsal segment of female 

 bilobed apically (see from below), with strong bristles beneath, espe- 

 cially toward its apex; areolet small, medium sized, or large, sometimes 

 open apically, usually approximately square or rectangular in shape; 

 first tergite rather strongly expanded apically, its spiracle well behind 

 the middle; ovipositor of moderate length or sometimes rather long, 

 stout, subcylindric or compressed, its tip with a series of teeth or 

 transverse or oblique ridges on dorsal valve between nodus and apex. 



The most distinctive characteristic of the subtribe is the ovipos- 

 itor tip, which has a series of oblique grooves on the dorsal valve, so 

 that the dorsal as well as the ventral valve is serrate. The body shape 

 is usually stout, with the thorax short, abdomen rather short, fiagel- 

 lum usually rather stout, and ovipositor of moderate length, or some- 

 times long in Glodianus. The areolet varies from small to large. In 

 two genera it is open. 



This relatively small group is widely scattered over the globe. It 

 seems reasonable that the genera contained in it are all phyleticaUy 

 related, but it could be that the ovipositor morphology is a con- 

 vergent development correlated with its use for piercing the thin dense 

 cocoons of the Eucleidae, and that the usually stout thorax is only a 

 correlation with development in the subspherical cocoons of the hosts. 

 The subtribe Baryceratina is proposed as a convenient unit, which 

 has a good chance of proving to be natural. Further studies will test 

 its validity. 



