A NEW SPECIES AND NEST TYPE OF MISCHOCYTTARUS 
FROM COSTA RICA (HYMENOPTERA: VESPIDAE; 
POLISTINAE), WITH DESCRIPTIONS OF NESTS 
OF THREE RELATED SPECIES 
By James M. Carpenter 1 and John W. Wenzel 2 
While engaged in a study of the nest architecture of paper wasps, 
one of us (JWW) discovered a remarkable nest of Mischocyttarus in 
the collection of the U.S. National Museum. The four associated 
adults proved to be an undescribed species. The genus Mischocytta- 
rus is the most speciose among social wasps, with 189 species recog- 
nized in the recent revision by Richards (1978). Snelling (1983) 
synonymized one of these species, but described one new one and 
raised one subspecies, and Raw (1985) described two more for a 
total of 192 presently recognized species. Nest architecture in the 
genus differs mainly in detail (Richards, 1978), but the new species 
builds a nest very different from its congeners. It is described below 
to bring it to the attention of behaviorists working in Costa Rica. 
Mischocyttarus pelor Carpenter, new species 
Diagnosis: A member of the subgenus Monogynoecus Richards, 
with a short pronotal carina, weak pronotal fovea, and weakly 
asymmetrical third segment of the midtarsus. In Richards (1978) it 
keys to fraudulentus Richards, with which it shares a blunt enlarged 
hindclaw. It differs in the shape of the first metasomal segment {cf. 
Figs. 1 and 2), in having the propodeum with the longitudinal carina 
more effaced dorsally ( cf. Figs. 2 and 3), and all metasomal terga are 
brown and banded with yellow. 
Type material: Holotype ? and three paratype ??, Turrialba, 
Costa Rica, 31 May 1951 (O. L. Cartwright). The holotype, two 
paratypes and nest are deposited in the U.S. National Museum; one 
paratype is in the Museum of Comparative Zoology. 
'Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts 
02138. 
2 Snow Entomological Museum, Snow Hall, University of Kansas, Lawrence, Kansas 
66045. 
* Manuscript received by the editor May 7, 1988. 
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