Key for identification of Neotropical genera of Hybotinae

1 Proboscis long and slender; labellum sclerotized, without pseudotracheae; Rs variable; abdomen pruinose .................................................................................................................. ............ 2

­ Proboscis short; labellum membranous bearing pseudotracheae; Rs short; abdomen shiny .... 6

2 Face short, eyes broadly dichoptic on face; Rs variable ............................................................ 3

­ Face long and linear or eyes holoptic on face; Rs short.............................................................. 5

3 Rs long, arising before middle of basal cells (br and bm); frons flattened; flagellum short, rounded ovate, with subdorsal arista; postcranium concave with conspicuous postocelar sclerite; male terminalia symmetrical ....................................................................... Syneches Walker

­ Rs short, beyond middle of basal cells; frons convex; flagellum pointed ovate, with apical arista; postcranium convex, without postocellar sclerite; male terminalia asymmetrical ......... 4

4 Distal section of R1 faint, sinuous, running parallel to the Costa; two pair of ocellar bristles; occipital bristles slender; 1 dc posterior bristle long; fore and mid tarsomere 1 without dorsal bristles; dorsal ejaculatory apodeme reduced ...................................................... Hybos Meigen

­ Distal section of R1 normal; one pair of ocellar bristles; occipital bristles spine­like; posterior dc bristle lacking; fore and mid tarsomere 1 with long dorsal bristles; dorsal ejaculatory apodeme developed ........................................................................................ Smithybos Ale­Rocha

5 Basal section of M and Sc weak or lacking; Rs with apex arched to meet R1 at right angle; wing with nude areas, without microtrichias; hind femur slender; hind tarsomere 1 short and thickened ................................................................................................................................ Syndyas Loew

­ M strong basally and Sc present; Rs with apex arched to meet R1 at acute angle; wing entirely clothed with microtrichias; hind femur thickened; hind tarsomere 1 long and slender................ .................................................................................................................. Lactistomyia Melander

6 Eyes distinctly dichoptic on face, rarely holoptic; wing narrow; anal lobe narrow, with rounded margin; R4+5 and M1 parallel, somewhat convergent; dc and acr with reduced number of bristles, arranged in discrete series on prescutellar disc; male eighth abdominal segment not rotated; hypandrial arms forming narrow, sclerotized dorsal bridge around phallus; hypandrium wider in the middle; Tg8 of female with a single sclerotized plate ............. Neohybos gen. nov.

­ Eyes holoptic on face, sometimes narrowly dichoptic; wing and anal lobe broad, rarely narrow; anal lobe triangular; R4+5 and M1 convergent; dc and acr with numerous and disordered bristles on prescutellar disc; male eighth abdominal segment rotated 45° to right; hypandrial arms prolonged distally forming membranous chamber dorsolaterally; hypandrium narrowed medially; Tg8 of female divided in three plates ........................................................................................ 7

7 Flagellum narrow, oval or conical; antennae inserted near middle of head; thorax strongly arched; pronotum elongate; mid tarsomere 1 with PV sub­basal bristle long; fore and mid tarsomere 1 with long dorsal bristles ................................................................ Euhybus Coquillett

­ Flagellum broad, strongly arched dorsally; antennae inserted high on head; thorax not strongly arched, almost flattened dorsally; pronotum short; PV sub­basal bristle of mid tarsomere 1 absent or reduced; fore and mid tarsomere 1 without dorsal bristles ............ Cerathybos Bezzi