Key to species of Elaphropeza Macquart, 1927 from the Amazon Basin

1 Hind tibia with 1 strong anterodorsal bristle ................................................................................................................ 2

- Hind tibia with 2 strong anterodorsal bristles .............................................................................................................. 3

2 Predominantly black species. Scutum with few setae, dorsocentral and intra-alar setae distinctly separated. Hind leg black, except basal half of femur yellow ..................................................... E. monochaeta (Bezzi, 1909) comb. nov.

- Yellow to reddish species. Scutum moderately hairy, dorsocentral and intra-alar setae hardly separated. All legs yellow to reddish yellow ....................................................................................................... E. biseticauda (Smith, 1963)

3 Occiput densely tomentose. Male fore femur with posteroventral spinule-like bristles, mid femur with 2–5 prominent anterior bristles on apical half. Male right cercus with clavate projection arising under membranous area that connects cerci .................................................................................................................... E. flavida (Williston, 1896)

- Occiput lacking tomentum at least on shining region adjacent to upper part of eye. Male fore femur lacking spinulelike bristles, mid femur lacking prominent anterior bristles (except apicals). Male right cercus without clavate projection........................................................................................................................................................................... 4

4 Postpronotal seta prominent. Vein R2+3 strongly arched, R4+5 remarkably divergent from M. Male cerci separated...... ............................................................................................................................................ E. mazaruni (Smith, 1963)

- Postpronotal seta indistinct. Vein R2+3 normally arched, R4+5 parallel to M near margin. Male cercus completely fused ................................................................................................................................................. E. similis (Smith, 1963)