Key to the species of Polyphrix Townes (modified from Nogueira and Aguiar (2005) and Santos et al. (2009))

1. Propodeum with one or two pairs of somewhat oval dark spots, a pair behind anterior transverse carina and with or without a pair in front of anterior transverse carina; hind trochanter, and trochantellus dark brown; mesoscutum completely black.... 2

- Propodeum uniformly orange, without dark spots; hind trochanter and trochantellus entirely yellowish; mesoscutum not completely black..................................................................................... 3

2. Paraocular stripe complete; pronotum with strong and distinct submarginal lamellar protuberance; anterior margin of propodeum centrally distinctly concave; ovipositor slender, dorsal valve with nodus, ventral valve with nine apical teeth, apical 3–4 teeth weak................................................................ Polyphrix cristata Nogueira & Aguiar

- Paraocular stripe interrupted from supraclypeal area to posterior orbit; pronotum with very weak submarginal protuberance; anterior margin of propodeum weakly sinuous; ovipositor thick, dorsal valve without nodus, ventral valve with seven apical teeth............................................................... Polyphrix atlantica Nogueira & Aguiar

3. Pronotum and mesoscutum completely orange (Figs 1A,D, & 2A,D)............................................ 4

- Pronotum and mesoscutum mostly black, with small yellow marks (Figs 3A,D)................................... 5

4. Transverse furrow at base of propodeum, measured centrally, about 1.2 as wide as basal area of propodeum; metafemur entirely yellowish....................................................................... Polyphrix varians Townes

- Transverse furrow at base of propodeum, measured centrally, about 0.7 as wide as basal area of propodeum; metafemur entirely blackish (Figs 1A, 2A)............................................................... Polyphrix misa sp. nov

5. Metasomal tergites 2–8 black with apical white stripe (Figs 3A,D); transverse furrow at base of propodeum, measured centrally, as wide as basal area of propodeum (Fig. 3D)........................................... Polyphrix tullu sp. nov.

- Metasomal tergites 2–8 entirely orange; transverse furrow at base of propodeum, measured centrally, about 0.7 as wide as basal area of propodeum....................................................... Polyphrix stellata Tedesco & Santos