Morphometric Variations in the Local Populations of Chrotogonus trachypterus (Blanchard).

Abstract

The observed linear morphometric variations within the local species of the surface grasshopper, Chrotogonus trachypterus (Blanchard) was evident as per mean values for the different traits measured. The lengths of antennae, tegmina, hind wing, body up to genitalia/ wing tip, pronotum, and the sternal region were relatively more for the females than the males; similarly the width of tegmina, body, pronotum, and the sternal region were also relatively more for the females. Variations in the linear measurements of the mouthparts and the legs of the grasshopper evinced that the females had relatively more length and width than that of the males for the different parameters observed; however, the maximum coefficient of variation was noted for the length of the galea (21.45 %) and for the tarsal region of the fore legs in either sex of the grasshopper. Comparison of the compounded ratios for some of the morphological traits showed that the ratio between length of hind femur and width of vertex (F/v) was the maximum (7.335 + 0.132 and 7.151 + 0.124 for the males and females, respectively). The lowest ratio happened to be for the ratio between the length and width of the pronotum (P/p) for both the males as well as the females (0.686 + 0.014 and 0.624 + 0.009).