Are Anatomical Measurements Useful for Interspecific and Sexual Differentiation of Temnomastax (Orthoptera: Eumastacidae) Species?

Species of Temnomastax have wide morphological similarities, and differentiation is usually based on male and female genitalia. In this study, we tested whether morphometric differences contribute to differentiation of species of Temnomastax, proposed an identification key for males, and morphometrically studied the sexual dimorphism of Temnomastax hamus and Temnomastax ricardoi. Analysis was performed using 204 specimens belonging to six species; fifteen morphometric variables were used. We used MANOVA and ANOVA to test the morphometric differences among species and Discriminant Analysis for sexual distinction. Temnomastax sp. nov. 1 had the highest values in ⅓ of all analyzed variables used for morphometric distinction of males, followed by Temnomastax latens, T. ricardoi and Temnomastax sp. nov. 2, and T. hamus and Temnomastax tigris. Two groups were formed by the MANOVA, with length of body, length of hind femur, and length of tegmen as the main variables that distinguished them. Overall, females of T. hamus and T. ricardoi presented higher averages for measurement values used in morphometric distinction between sexes than conspecific males and based on discriminant analysis we found significant differences between sexes. There are significant differences in morphometric variations and the ratio between body length and tegmen length provided reliable evidence for differentiation among species, which can be used as a valid tool that complements the identification of Temnomastax species.