Comparative Morphology of Three Orthopteran Species (Microcentrum rhombifolium, Mecopoda elongata, Schistocerca americana) from Kalahandi, Odisha, India

Abstract

Background: Comparative morphological studies of orthopterans reveal evolutionary adaptations to ecological niches, informing biodiversity assessments in diverse regions like Odisha, India.    This study examines external morphology of Microcentrum rhombifolium (Pseudophyllinae), Mecopoda elongata (Tettigoniinae), and Schistocerca americana (Acridinae) from Kalahandi District. Objective: To compare body form, wing structure, leg morphology, and diagnostic traits, linking variations to habitat preference, locomotion, feeding, and survival mechanisms for enhanced form function understanding. Methods: The specimens were collected across Kalahandi (19.3–21.5°N, 82.20–83.47°E), identified via taxonomic keys, photographed post freezer paralysis, measured with vernier calipers (0.1 mm precision), and selectively preserved in 70% ethanol. Results: The M. elongata showed largest dimensions (body 75.55 mm; hind limb 100.65 mm; antennae 49.88 mm), which are suited for acoustic signaling and foraging. S. americana had compact form (body 58.86 mm; pronotum 11.74 mm; hind femur 28.15 mm; tibia 29.97 mm) adapted for jumping and swarming. M. rhombifolium (body 62.99 mm) featured rhomboidal tegmina with reticulate venation that ais in crypsis. Wing morphologies diverged among the species, being  cryptic in M. rhombifolium, aerodynamic in S. americana, multifunctional in M. elongata. Hind legs converged between S. americana and M. rhombifolium (femur ~28 mm; tibia ~30 mm) despite familial differences. Conclusion: Distinct wing and leg adaptations underscore Orthoptera's morphological plasticity and taxonomic utility, with convergence highlighting biomechanical demands for jumping.