20 z. bouCek 



distinct angle with outer outline of eyes; subocular suture lacking. Mouth narrow, mandibles 

 weakly curved. Palpi rudimentary; labial ones 3-segmented, each segment subquadrate; 

 maxillary ones either missing or indicated by a scar, or reduced to a tiny 3-segmented brush 

 half as long as breadth of ocellus (Text-figs 17, 18). Pronotum short, without any cross- 

 carinae although the premarginal sometimes indicated by a swelling; sides in dorsal view 

 emarginate; lateral panel with relatively sharp lower corner, hind margin deeply emarginate 

 at spiracle. Mesoscutum with fine linear notauli anteriorly, vestiges of parapsidal furrows 

 at postero-lateral corners not conspicuous. Propodeum in both sexes long, medially elevated, 

 hind margin of median part more or less produced and usually hardly broader than the 

 emarginate gap separating it from the tooth-like postero-lateral corner. Dorsal edge of hind 

 coxa broad, convex, always without piliferous punctures, posteriorly with digitiform tooth. 

 Hind femur often slender, basal tooth always the largest and situated in or beyond middle 

 (Text-figs 16, 21, 27). Hind tibia perpendicularly truncate at apex, outer spur longer than 

 inner one; outer ventral carina not reaching apical half of tibia. Fore-wing: stigmal vein 

 about as long as or shorter than its uncus (Text-fig. 20) which is subparallel to margin; 

 apical processus lacking. Gaster in dorsal view not very different in the two sexes; ovipositor 

 sheaths subhorizontal, nearly straight, confined to ventral side, not up-turned; consequently 

 in both sexes sixth (spiracle bearing) tergite longest in the median line. 



Biology. Hosts of two species are the bees of the genus Euglossa Latreille 

 (Apidae), i.e. insects of quite different appearance from the Polistine wasps which 

 Polistomorpha species mimic. 



Distribution. Central and South America (7 species). The Indian species 

 placed in Polistomorpha by Mani (1935; 1936; 1938) belong to Leucospis 

 Fabricius. 



Key to the species of POLISTOMORPHA 



1 Dorsellum quadrangular (Text-fig. 25), transverse, beset with coarse piliferous 



punctures similar to those on scutellum; in 9 epipygium in dorsal view bidentate 

 (Text-fig. 24) ; maxillary palpi rudimentary but present, 3-segmented (Text-fig. 18) ; 

 pronotum with median triangular black spot, body predominantly testaceous, 

 gaster usually with conspicuous alternating testaceous and brown bands 



fasciata Westwood (p. 22) 



- Dorsellum more or less triangular (Text-fig. 26), densely hairy and finely punctured; 



in O. epipygium not bidentate; maxillary palpi reduced to a scar (Text-fig. 17); 

 pronotum without median triangular spot; body either predominantly testaceous 

 or black but gaster not conspicuously banded ....... 2 



2 Dorsellum carinately margined; body predominantly testaceous, with black or 



brown pattern ; impunctate upper part of hind coxa finely cross-striate ... 3 



- Dorsellum not carinately margined; body often predominantly black; upper part of 



hind coxa striate or smooth .......... 6 



3 Sixth tergite in $ conically overlapping epipygium which is confined to ventral side 



and is not visible from above (Text-fig. 30) ; in $ sixth tergite in profile with 

 distinct boss (Text-fig. 31) ....... conura sp. n. (p. 22) 



— Gaster otherwise, in Q. epipygium not concealed under sixth tergite, so that two 



segments are visible from above behind fifth (largest) tergite ; ^ unknown . . 4 



4 Hind femur slender (Text-fig. 16), about twice as long as broad, outer ventral carina 



of hind tibia confined to basal third; scutellum with dense and fine puncturation 

 similar to that on mesoscutum and dorsellum; apex of gaster conical (Text-fig. 16) 



surinamensis (Westwood) (p. 25) 



— Hind femur broader, at most 1 -8 times as long as broad ; scutellum with conspicuously 



coarser and less dense puncturation than mesoscutum and dorsellum; apex of 

 gaster otherwise ............ 5 



