Re-description and bio-ecology of two species of the genus Thibron (Rehn, 1938) (Orthoptera: Tetrigidae) in the Southern part of Cameroon

Abstract

Taxonomy and bio-ecology of Tetrigidae in Cameroon remain poorly studied. This study reports for the first time the presence of Thibron cf. tectatus Günther, 1979 in Cameroon and provides morphological and bio-ecological characteristics of Thibron illepidus (Karsh, 1893) and T. cf. tectatus. The specimens studied were collected between February 2016 and February 2018 in three regions of Cameroon. In each region, species were collected monthly using sweep-nets and pitfalls in four vegetation types. Some morphological characters formerly omitted in previous descriptions were considered in this study. In addition to the characters already known, T. illepidus differs from other species of the same genus in terms of length of body and interocular space, posterior thigh width, median femur length and width and finally the length of the three tarsomeres of posterior tarsus only in T. illepidus. In addition, for T. cf. tectatus, the length of the head, fastigium of vertex, eyes are longer than in T. illepidus. The later was more abundant in the Centre region (79%), less abundant in the Southwest region (18%) and rare in the West (3%). Meanwhile, Thibron cf. tectatus is rare in the Centre region (4%). Pitfalls (92%) were more effective than sweep-nets (8%) in capturing T. illepidus. Results obtained could contribute to improve the knowledge of the taxonomy of both species in Cameroon.