Key to Lutosa species based on males

1. Hind tibia straight, paraprocts unarmed, or if they are armed with processes in variable shapes........................ 2

- Hind tibia curved, each paraproct with a forked process at the apex.................................... L. brasiliensis

2. Posterior border of the subgenital plate, in dorsal view with calluses, with or without denticles (Figs. 8D, E)............. 3

- Posterior border of the subgenital plate, in dorsal view without modifications or sclerotized calluses (Figs. 2F, 7B)........ 6

3. Fore tibia with tympana (Fig. 8A). Posterior border of the subgenital plate almost straight and with well-sclerotized calluses (Fig. 8E)............................................................................................ 4

- Fore tibia without tympana (Fig. 10C). Subgenital plate with a U-shaped notch and with moderately sclerotized calluses............................................................................................. L. paranensis

4. Dorsal surface of the body with constant coloration, predominantly dark brown or black (Fig. 8B)..................... 5

- Dorsal surface of body variable, pro- and mesonotum reddish brown, metanotum and other abdominal tergites light reddish brown, with posterior border outlined in black (Fig. 6B).............................................. L. cubaensis

5. Epiproct triangular; paraproctal processes broad, flattened dorsoventrally, and well sclerotized (Fig. 8D). Posterior border of the subgenital plate almost straight, with a slight undulation (Fig. 8E)..................................... L. goeldiana .

- Epiproct quadrangular; paraproctal processes small, slender, and hooked. Posterior border of the subgenital plate with a small medial rectangular prolongation................................................................... L. imitata

6. Membranous space between the tenth tergite broad and in the shape of an inverted crescent moon. Epiproct rectangular, longer than wide, with a rounded posterior edge. Paraproctal processes slender and hooked, curved downwards and conspicuously protruding on the sides of the epiproct............................................................ L. normalis

- Membranous space between the tenth tergite narrow and inverted-Y-shaped. Epiproct triangular, as long as wide. Paraproctal processes like a short hook, curved upwards and slightly protruding on the sides of the epiproct (Fig. 2E).................................................................................................... L. quaresmai n. sp.