Syntopic call diversity among morphologically similar calling morphs of the palaeotropical katydid of genus <i>Mecopoda</i> (Tettigoniidae) from an Indo-Burma biodiversity hotspot

The acoustically diverse family of Tettigoniidae (Ensifera, Orthoptera) (commonly called bushcrickets or katydids), constitutes an excellent system to study the evolution of calling songs. <i>Mecopoda</i> is a genus that is particularly interesting because of the many morphologically cryptic calling morphs that have been described across South, East, and Southeast Asia, some of which are considered endemic to India. We describe five new syntopic and sympatric calling morphs of the genus <i>Mecopoda</i> that are morphologically similar but acoustically diverse from a sub-tropical forest in Meghalaya, in the Indo-Burma biodiversity hotspot. We report the morphological and acoustic characterisation of these five call types, finding morphological overlap but well-separated acoustic clusters based on a PCA analysis of call temporal and spectral features. We also sequenced the COI gene mitochondrial gene of these five call types as well as other call types previously reported from India and performed a phylogenetic analysis of this gene relative to previously reported COI gene sequences from genus <i>Mecopoda</i>. Phylogenetic results suggest our five call types are not mutually monophyletic and relate to different subspecies of <i>Mecopoda</i>, of which three call types are genetically well separated from other calling morphs. This broadens our understanding of the evolution of acoustic diversity among palaeotropical katydids.