Sphecoidea of Nebraska 109 
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PEMPHREDONINAE 
KEY TO THE TRIBES 
Eyes small, their inner margins subparallel or converging to clypeus; head 
usually quadrate or subquadrate, well developed behind eyes; species 
shining; episternauli present except in Spilomena; usually nest in wood, 
Pemphredonini 
Eyes large, their inner margins converging to vertex; head subtransverse, 
scarcely developed behind eyes; species opaque; episternauli wanting; 
Pe Valea a ta CARA A a Re Re ete eats hs wie wie oa OSEAN Miscophini 
PEMPHREDONINI 
KEY TO THE GENERA 
1. Anterior wings with only one recurrent nervure; abdomen with a dis- 
EIU ERE CLONLE Wier Sc' > crcnetscate ucla: Nialeiale ate a orcas) ate auctor aietara\ aie! eeu Senet Stigmus 
Anterior wings with two 'rectirrent Mervures ..........ce0-cccnenes z 
2. Abdomen with the petiole longer than the hind coxae; mandibles tri- 
LEME eee ees an ales Sure wis Soe gadn otal Momre sete oha ersisisimiaiaceree Pemphredon 
Abdomen with the petiole never longer than the hind coxae ........ 3 
3. Hind tibiae along the outer face spinous or subserrate; clypeus at’ apex 
STAR ASIME Le Hye oy BORER ACI SCI TROT Sarre er DOC IO Xylocelia 
Hind tibiae along the outer face smooth, unarmed; labrum triangularly 
PIRSA Sack ate ear aecawye SG e%s, «5s Fite. @reia.s's grails wala SS Passaloecus 
Stigmus Panzer 
KEY TO THE SPECIES 
Females 
Clypeus not bilobate, at the most slightly emarginate medially; third joint 
of antennae longer than the fourth; length 4 mm. .......... americanus 
Clypeus distinctly bilobate medially; dorsulum with very fine longitudinal 
SEEN i See ee Oe ee on mb Maen em eet ra fulvipes 
Stigmus americanus Packard. 
1867. Stigmus americanus Packard, Proc. Ent. Soc. Phil., VI, p. 386. 
1892. Stigmus americanus Fox, Trans. Amer. Ent. Soc., XTX, p. 322. 
Males 4, females 4: Omaha (3), Glen (4); July 15 to August 
20. 
Stigmus fulvipes Fox. 
1892. Stigmus fulvipes Fox, Trans. Amer. Ent. Soc., XIX, p. 324. 
Females 1: Bad Lands, August 10, 1908 (L. Bruner). 
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