Key to the males of Nyetnops Platnick & Lise, 2007 updated from Sánchez-Ruiz et al. (2020)

1. Without remarkable dorsal abdominal pattern (Sánchez-Ruiz et al. 2020: figs 1a, g, 4a, g) ........... 2

– With remarkable dorsal abdominal pattern of chevron stripes (Fig. 9A) .................................................................... Nyetnops josei Villarreal & Martínez sp. nov.

2. Length of copulatory bulb (tegulum +embolus) just two times or less the palpal tibia length (Fig. 4A–B Sánchez-Ruiz et al. 2020: figs 1b–d, 4b–c) ................................................................... 3

– Length of copulatory bulb (tegulum+embolus) more than 2.2 × as long as palpal tibia (Sánchez-Ruiz et al. 2020: figs 8b–c; 9b–c) ..................................................................................................... 5

3. Tegulum apical section not swollen on median portion, same width as tegulum basal section (Figs 4A–B, 5A, G) ..................................................... N. alexanderi Villarreal & Martínez sp. nov.

– Tegulum apical section swollen on median portion (Sánchez-Ruiz et al. 2020: fig. 7a–f) .............. 4

4. Tegulum apical section swollen on median portion, width similar to palpal tibia (Sánchez-Ruiz et al. 2020: figs 4b–c, 8h), embolus tip with very long rooster’s crest like projections (Sánchez-Ruiz et al. 2020: fig. 7a–f) .......................................... N. naylienae Sánchez-Ruiz, Brescovit & Bonaldo, 2020

– Tegulum apical section weakly swollen on median portion, narrower than palpal tibia width (Sánchez-Ruiz et al. 2020: fig. 1b–c), embolus tip beveled with short projections (Sánchez-Ruiz et al. 2020: fig. 3g –i ...................................................................... N. guarani Platnick & Lise, 2007

5. Mid of palpal tibia strongly swollen, 1.8 × as wide as proximal and distal portions (Sánchez-Ruiz et al. 2020: fig. 8b–c); copulatory bulb slender, weakly swollen on tegulum apical section, only a half palpal tibia width (Sánchez-Ruiz et al. 2020: fig. 8b–c) ............................................................. ..................................................................... N. lachonta Sánchez-Ruiz, Brescovit & Bonaldo, 2020

– Mid of palpal tibia weakly swollen, only 1.2 × as wide as proximal and distal portions (Fig. 6A–B; Sánchez-Ruiz et al. 2020: fig. 9b–c) ................................................................................................. 6

6. Copulatory bulb thick, slightly swollen at tegulum apical section and narrow at basal section (Sánchez-Ruiz et al. 2020: figs 8i, 9b–c) ........ N. buruti Sánchez-Ruiz, Brescovit & Bonaldo, 2020

– Copulatory bulb very slender, not swollen at tegulum apical section and slightly swollen at basal section (Fig. 6A–B) ................................................. Nyetnops madre Villarreal & Martínez sp. nov.