69 



(iii) SYNOPSIS OF KAUAI ODYNERUS. 



1 (6) Dorsal and posterior faces of the post-scutellum separated by a 



fine spinulose or serrulate ridge cr raised line. 



2 (3) Abdomen entirely black, or very rarely with the apical margin 



of the basal segment yellow. Odynerus nigripennis. 



3 (2) Abdomen with two distinct yellow or whitish bands. 



4 (5) Basal abdominal segment completely rounded off at the meeting 



of its dorsal and anterior surfaces. O. radula. 



5 (4) Basal abdominal segment slightly depressed on its dorsal sur- 



face, so that this forms with the anterior surface a rather 

 distinct edge, where they meet. O. localis. 



6 (1) Dorsal and posterior faces of the post-scutellum not separated 



by a distinct raised line. 



7 (10) Thorax and abdomen with red markings. 



8 (9) Pronotum with a fine transverse red line, entire or broken. 



O. soror. 



9 (8) Pronotum without a red line. O. blackburni. 



10 (7) Thorax and abdomen without red markings. 



11 (12) Abdomen with the bands orange or deep yellow. 



O. xanthorhoes. 



12 (11) Abdoinen with pale yellow or whitish bands. 



13 (14) Second ventral segment very strongly and abruptly raised 



behind the sulcature, to a height much exceeding that of 

 the basal part of the segment (the costae more or less 

 obliterated, and no depression behind the sulcature). 



O. mimus. 



14 (13) Second ventral segment not so raised (only in a few species 



attaining a height about equal to that of its basal portion). 



15 (18) Costae very short, shorter than the tumid basal portion of the 



segment; cr nearly or quite obsolete, the sulcature being 

 smooth; the depression absent or very faint and linear. 



16 (17) Sulcature mostly smooth, the costae nearly absent, generally 



visible as traces only along the basal margin of the sulcature. 



O. nesiotes. 



17 (16) Costae short, but strong; basal part of segment large and tumid. 



O. vittativentris. 



18 (15) Costae of second ventral segment not very short, the middle 



ones generally long and not shorter than the basal portion 

 of the segment, or with a distinct large or largish depression 

 behind the costae. 



19 (62) Second ventral segment flat behind the costae, no distinct 



depression. 



20 (21) Second dorsal segment very abruptly and strongly raised from 



the base into a conical tuberculate form (middle tibiae 

 without a calcar). Nesodyneriis conifer. 



21 (20) Second dorsal segment not so raised. 



