Polauchenia

Key for the species of PoLauchenia, modified from Wygodzinsky (1966)

1. Postocular region of the head with a median spine, besides a pair of lateral spined tubercles...... unicornis Maldonado, 1968

- Postocular region of the head without a median spine, with or without a pair of lateral spined or rounded tubercles........ 2

2. Petiole of pronotum quite longer, at least 1.5 times as long as the fore lobe........................................ 3

- Petiole of pronotum little, if any longer than fore lobe......................................................... 5

3. Petiole of pronotum approximately 1.5 times as long as the fore lobe; length 14 mm............. P. paraprotentor sp. nov.

- Petiole of pronotum at least twice longer than the length of fore lobe; length 15 mm or longer.........................4

4. Length 17.5 mm; females (males unknown) brachypterous, the forewing reaching at about middle of abdomen........................................................................................ marcapata Wygodzinsky, 1966

- Length not more than 15 mm; humeri spined; female slightly brachypterous, forewing reaching far posterior to the middle of abdomen................................................................. protentor McAtee & Malloch, 1925

5. Length 11 mm; postocular region of the head without projections, spines of scutellum and metanotum yellowish........................................................................................ schubarti Wygodzinsky, 1950

- Length 16 mm; postocular region of the head with a pair of spined conical tubercles; spines of scutellum blackish................................................................................. biannulata McAtee & Malloch, 1925