Fig. 1

Map showing the distribution and sampling details of each species. Shaded area corresponds to the range of C. sphinx across India. Dotted areas correspond to the range of C. brachyotis lineage across India. Distribution maps for both species were obtained from International Union for Conservation of Nature. Rajasri Ray provided the shape files of the political boundary of India as well as the boundaries of the Eastern Ghats and Western Ghats. While C. sphinx is found across various habitat types at lower altitudes, C. brachyotis is restricted to mountain ranges [18]. In southern India, C. brachyotis is reported from the Eastern Ghats and the Western Ghats mountain ranges ([18] and the present study). In the map, we have denoted the Eastern Ghats in green and the Western Ghats in yellow. Sampling locations are presented as black dots with numbers corresponding to a population. Locations corresponding to areas of coexistence are marked in pink dots. Details of sampling are provided in Additional file 1: Table S1