Diversity and Spatial Distribution of Caelifera (Orthoptera) along Canopy Gradients in Aralam Wildlife Sanctuary, Kerala

Short-horned grasshoppers (Orthoptera: Caelifera) are among the least studied insects in the Western Ghats. This study assessed their diversity and spatial distribution across canopy cover gradients in Aralam Wildlife Sanctuary, part of Western Ghats in Kerala. Surveys were conducted from 2022 to 2024 in three habitats: semi-evergreen forest, evergreen forest, and teak plantations, using visual transect counts and sweep netting. Canopy cover was measured via hemispherical photography and analysed using ImageJ. A total of 33 species from 27 genera and 12 subfamilies were recorded. Semi-evergreen forest (60-80% canopy) had the highest species richness (25) and diversity indices (Shannon: 2.169; Simpson: 0.8608). Interpolation mapping revealed diversity hotspots and potential conservation zones. Study highlights canopy structure as a key driver of grasshopper diversity, providing valuable insights for biodiversity conservation in the sanctuary.