4 U. S. NATIONAL MUSEUM BULLETIN 216 



The subfamilies (formerly Pimplinae of authors) here included 

 are separated by the following key : 



1. Female subgenital plate very large, triangular, folded on the midline, its apex 



reaching or surpassing the apex of abdomen (figs. 308-310,a) ; apical third 

 of abdomen of male compressed (deeper than wide) . 3. Acaenitinae (p. 544) 

 Female subgenital plate not enlarged, or if rarely enlarged (as in Clistopyga) 

 not triangular and folded on midline (figs. 285-307) ; apical third of abdomen 

 of male cylindric or depressed (wider than deep) 2 



2. First abdominal sternite more or less free from its tergite (and the first tergite 



with a glymma), and/or the propodeum not areolated; epipleura often 

 narrow or vestigial, but sometimes wide .... 1. Ephialtinae (p. 4) 

 First abdominal sternite completely fused with its tergite (and the first tergite 

 without a glymma); propodeum areolated; epipleura moderately wide to 

 very wide 2. Xoridinae (p. 436) 



Subfamily Ephialtinae 



Figures 284-304,a 



Front wing 2.5 to 30 mm. long; apical margin of clypeus typically 

 thin and with a median notch that makes it bilobed, but often (as in 

 Polysphinctini, Poemeniini, and Rhyssini) of other shapes; labrum 

 hidden beneath clypeus and mandibles; propodeum with few or no 

 areas bounded by carinae except in Xanthopimpla, some Polysphinc- 

 tini, and the Theroniini; costula present only in some Xanthopimpla 

 and Theronia; tarsal claws often with an accessory tooth or basal 

 lobe, especially in female; first sternite usually free from its tergite, 

 the tergite with a glymma when its sternite is free; epipleura moder- 

 ately wide to very narrow or vestigial; apical third of abdomen usually 

 depressed or cylindric but in some females (especially Rhyssini) 

 somewhat compressed; female subgenital plate usually transversely 

 rectangular and weakly sclerotized, often with a median mem- 

 branous area, never with a long median point. 



The larva of the Ephialtinae differs from that of all other ichneu- 

 monids in having the sclerotic spur of the hypostoma and the stipital 

 sclerome both well developed and reaching each other at their apices 

 rather than the sclerotic spur reaching the stipital sclerome before 

 its apex. The antenna is usually well developed and the mandible 

 with teeth, but in the Ephialtini the antenna is vestigial and the 

 mandible without teeth. 



This is the largest group of the subfamily 'Timplinae" of recent 

 authors and contains many common, well known species. Though 

 it appears to be a very primitive group the species and genera are 

 still rapidly subdividing, which results in some taxonomically dif- 

 ficult situations. 



The subfamily contains the genus Pimpla and might be called 



