Key to species of the genus Hyperstoma

1. Antennomeres 1–2 light brown, 3-11 dark brown. Terminal abdominal tergum shorter than lateral protrusions of penultimate tergum (Fig. 9), forming slender apertures along terminal tergum; apex of phallus truncated, emarginate distally, basal portion of phallus provided with forked appendage, parameral apices truncated, with oblique edge distally... Hyperstoma marginata

- Antennomeres 1–6 yellow to light brown, 7-11 dark brown. Terminal abdominal tergum longer than lateral protrusions of penultimate tergum (Fig. 10) with moderately hooked thorn in 2/3 of its length, longitudinal aperture along terminal tergum circular basally; apex of phallus rounded, basal portion of phallus provided with forked refracted appendage, parameral apices rounded...................................................................... Hyperstoma wittmeri sp. nov.