4 PEOCEEDINGS OF THE iSTATIONAL MUSEUM tol. 69 



mandibles; the labrum nearly always conspicuous and filling the 

 space between clypeus and mandibles; labium sometimes extented; 

 occiput immargined; parapsidal furrows usually, though not always, 

 impressed; prepectal carina usually very distinct; first cubital and 

 first discoidal cells nearly always confluent (in the Nearctic forms 

 separated only in Earinus) ; radial cell always exceptionally nar- 

 row and ending far before apex of wing, always complete; the radius 

 strong and distinct to the wing margin ; second cubital cell small, tri- 

 angular, subtriangular or subquadrate, sessile or petiolate complete, 

 both intercubiti l)eing present; mediella straight, the second abscissa 

 on a line with the first; submediellan cell varying in length; abdomen 

 usually sessile, rarely subpetiolate ; ovipositor varying from not 

 exserted to longer than the body. The wing characters alone will 

 practically always indicate species of Braconinae. 



In order to prevent any possible misunderstanding with regard to 

 the terms used in designating wing characters in the following keys 

 and descriptions, a detailed explanation of wing veins and cells is 

 given below the accompanying figure of the wings of Bassus sanchis 

 Say. 



Comparatively little is known regarding the specific host relation- 

 ships of the various species of Braconinae. Most of the species, how- 

 ever, are undoubtedly parasitic on lepidopterous larvae, although 

 some appear to attack certain coleopterous borers in the stems of 

 herbaceous plants. 



KEY TO THE NEARCTIC GENERA OF BRACONINAE 



1. First cubital cell completely separated from the first discoidal; second cubi- 



tal cell quadrate or subquadrate, broadly sessile; parapsidal furrows want- 

 ing; tarsal claws with a large basal tooth; ovipositor sheaths unusually 



broad and densely hairy Earinus Wesmael. 



First cubital cell confluent with the first discoidal -2. 



2. Tarsal claws, at least those of the anterior legs, distinctly cleft; second cubi- 



tal cell quadrate or subquadrate sessile; the second abscissa of radius usually 

 much longer than the first — if not, then the apical segment of posterior 

 trochanters strongly carinately margined beneath on the outer side; frons 

 margined laterally by a distinct carina or ridge; propodeum coarsely aero- 



lated; abdomen always completely polished 3. 



Tarsal claws simple or with a broad basal tooth, never cleft; areolet usually 

 triangular or subtriangular, the second abscissa of radius rarely distinct and 

 then very short; apical segment of posterior trochanters never carinate 

 beneath; frons usually immargined; sculpture of propodeum and abdo- 

 men variable 4. 



3. Face not rostriform; the eyes unusualy large, the malar space very short, 



rarely one-fourth as long as the eyes; apical segment of posterior trochan- 

 ters distinctly carinately margined beneath on the outer side; inner spur 

 of hind tibia much more than half as long as the posterior basitarsus; scu- 

 tellum distinctly margined at apex; scape of antennae unusually large and 

 much longer than the first flagellar segment; ovipositor sheaths shorter 

 than the first abdominal tergite Zelomorpha Ashmead. 



