(after Bernard, 2006) Antenna with or without eversible sac between Ant III and IV. Six to eight sensilla on Ant IV. Ventral sensory file on Ant IV, when present, with 30 or fewer modified setae. Mandible with four or five apical teeth and well-developed molar plate. Maxilla with six lamellae, the fourth one reduced, not exceeding apex of the fifth one. Guard setae of labial palpus pointed; lateral process present or absent. Postantennal organ small, with four small distinct lobes, or simply oval with lobes indistinct; accessory tubercle absent. Unguis with or without tooth, tenent hairs acuminate or clavate. Unguiculus with or without lamella. Pronotum usually with 2 + 2, rarely with 3 + 3 setae. Ventral tube with 4 + 4 or 5 + 5 setae. Tenaculum with 4 + 4 teeth. Dens with six or seven setae, one proximal seta longer than others; mucro with a latero-external lamella of variable shape, its apex tapering, curved. Anal spines minute or absent.

Cosberellaconatoa Wray, 1963.

The Mexican species described here is assigned to the genus Cosberella. It recalls also the genus Choreutinula by the absence of anal spines and a small PAO with four flattened lobes. However, this genus lacks of unguiculus, or has only a short thin bristle in its place, while the unguiculus of the new species is well developed, straight and half as long as claw, and the fourth maxillary lamella is reduced, not exceeding apex of the fifth one, which are characteristics of genus Cosberella.