Key to Afrotropical Isocanace Mathis

1. Antennal arista with branches long (Fig. 2), some almost double or more than aristal width at base; anepisternal and usually katepisternal setae pale, mostly yellow; male terminalia with posterior part of surstylus (in lateral view) with more or less prominent heel-shaped swelling (Figs 4, 5) (Aldabra Is. & Madagascar).............................. I. briani Mathis

- Antennal arista with branches distinctly shorter (Fig. 3), as long as, or marginally longer than, aristal width at base; anepisternal and katepisternal setae black; male terminalia (in lateral view) with posterior part of surstylus without heel-shaped swelling (e. g., Fig. 6)......................................................................................... 2

2. Thorax with anterior notopleural seta present, although weaker and shorter than posterior seta; male terminalia (in lateral view) with surstylus lacking a protruding swelling on anteromedial part, but if swelling present, then this reduced in distal 2 / 3 of lateromedian side, bearing cluster of long setulae; surstylus (in lateral view) with gently curved, posteromedial margin, or otherwise, with apical 1 / 3 narrow and curved posteriorly (Mathis 1999, fig. 14)............................................. 3

- Thorax with anterior notopleural seta absent or very weak and pale; male terminalia (in lateral view) with surstylus bearing strongly protruding swelling on anteromedial part; surstylus (in lateral view) with broadly curved posteromedial margin... 4

3. Male terminalia (in lateral view) not as described below, with surstylus very long and narrow, with subapical posterolateral swelling bearing cluster of pale setulae, apical 1 / 3 curved posteriorly (Mathis 1999, fig. 14) (Kenya & South Africa)............................................................................................. I. australis Mathis

- Male terminalia in lateral view with foot-like surstylus (Fig. 6) (broadly resembling that of I. briani (Figs 4, 5), but without posterior heel-shaped swelling), with proximal stem long and slender, neck-shaped, mid part moderately swollen, ending distally with anteriorly oriented, sickle-shaped, apical tip (Mauritius)............................ I. mauritiana Munari sp. nov.

4. Head with 4 lateroclinate fronto-orbital setae; male terminalia with surstylus (in lateral view) narrow, sharply hooked apically, with narrow hook-like tip oriented anteriorly (Mathis 1999, fig. 29) (Democratic Republic of Congo)............................................................................................ I. flava (Canzoneri & Meneghini)

- Head with 3 lateroclinate fronto-orbital setae; male terminalia with surstylus (in lateral view) strongly broadened medially, tapered apically, with large triangular tip oriented anteriorly (Mathis 1999, fig. 30) (Kenya)............ I. freidbergi Mathis