Key to Afrotropical genera of Diaphorinae

1 Costa not extending beyond tip of R 4+5; distal vein M gently sinuate or broken or weakened, with distal section often displaced .......................................................2

– Costa extending beyond tip of R 4+5, usually ending at apex of vein M; vein M unbroken, rarely weakened ....................................................................................5

2 Vein R 4+5 ending along distal anterior wing margin, well before wing apex; distal parts of R 4+5 and M 1+2 strongly diverging...............................................................3

– Vein R 4+5 ending almost at wing apex; distal parts of R 4+5 and M 1+2 subparallel, slightly diverging or bowed with respect to each other .........................................4

3 Upper part of proepisternum with 2–4 fine setae; acrostichals usually present; male sternite 8 often with strong projecting setae ...................... Asyndetus Loew, 1869

– Upper part of proepisternum usually bare; acrostichals absent or microscopic; male sternite 8 without strong setae.............................. Cryptophleps Lichtwardt, 1898

4 Acrostichals biseriate; male antenna very long (4/5 the body length); male fore and mid tarsi modified; male sternite 8 with 2 strong projecting setae .......................... ........................................................................................... Aphasmaphleps gen. n.

– Acrostichals absent; male antenna about as long as head height; male fore and mid tarsi simple; male sternite 8 without strong setae; western Pacific.......................... .................................................................................[Phasmaphleps Bickel, 2005]

5 Occiput concave; antennal postpedicel usually pressed laterally, bladelike to subtriangular, with distinct apex and dorsal to dorsoapical arista-like stylus.............6

– Occiput convex or flat; antennal postpedicel usually globular, reniform, conoid or budlike, with indistinct apex, or with slender apical projection, and with subapical or apical, rarely dorsal, arista-like stylus inserted sometimes in apical incision ...8

6 Hind coxa with external vertical row of 3 or 4 setae decreasing in length ventrally; scape with dorsal setae (bare in some Holarctic species) ........................................ ........................................................................................... Argyra Macquart, 1834

– Hind coxa with one external seta at basal quarter; scape bare...............................7

7 Wing vein M 1+2 with rather distinct sinuation at 2/5 of distal part; arista-like stylus dorsal; antennae positioned at upper quarter of head; male segment 7 rather long ......................................................................................... Urodolichus Lamb, 1922

– Wing vein M 1+2 nearly straight; arista-like stylus dorsoapical; antennae positioned at middle of head; male segment 7 short; Azores .................................................... ........................................................................... [Falbouria Dyte, 1980; Figs 8, 9]

8 Posterior four femora with anterior subapical seta in both sexes; male frons and face broad...............................................................................................................9

– Posterior four femora without distinct anterior subapical seta, at most with stiff hairs; male eyes usually convergent or contiguous above or below antennae.....10

9 Antennal pedicel with finger-like projection overlapping postpedicel; male sternite 8 with strong projecting setae ...................................... Dactylonotus Parent, 1934

– Antennal pedicel without finger-like projection; male sternite 8 without strong setae......................................................................... Nurteria Dyte & Smith, 1980

10 Acrostichal setae absent; female clypeus with four projecting setae; male segment 7 rather long; postgonite prominent, often with a group of pedunculate setae........ .............................................................................................. Acropsilus Mik, 1878

– Acrostichals present, biseriate; female clypeus without setae; male segment 7 short; postgonite reduced ...............................................................................................11

11 Antennae positioned at middle of head; upper part of proepisternum with 2–4 fine setae; wing usually broadest at basal quarter, with nearly straight R 4+5 and M veins ............................................................................... Diaphorus Meigen, 1824

– Antennae positioned at upper quarter to third of head; upper part of proepisternum usually bare; wing usually broadest at middle, with convex anteriorly R 4+5 and M veins .....................................................................................................................12

12 Face nearly parallel-sided, subequal in width to frons; male postpedicel budlike, with abruptly drawn-out apex; male sternite 8 with strong projecting setae; hypopygial surstylus and epandrial lobe long and thin; male cercus with long distoventral projection ...................................................................... Trigonocera Becker, 1902

– Male eyes convergent or contiguous below antennae; female face distinctly narrowed downwards; male postpedicel globular, reniform, conoid (Chrysotus) or with slender apical projection (Achradocera); male sternite 8 with simple hairs, rarely with short thick setae; surstylus and epandrial lobe broad; male cercus without distoventral projection .............................................................................................................13

13 Male postpedicel with slender apical projection bearing apical arista-like stylus, and lower postocular surface of male with many flattened pale setae ..................... ..................................................................................... Achradocera Becker, 1922

– Male postpedicel globular, reniform or conoid with subapica1 arista-like stylus; lower postocular surface with fine unmodified setae...... Chrysotus Meigen, 1824