The experiment was conducted to check the effect of weather parameters on scarab beetles diversity collected from the light trap in grassland ecosystem at CSWRI, Avikanagar, Tonk, Rajasthan during July 2024 to July 2025. A total of 36 species were recorded, belonging to 18 genera under 10 subfamilies viz., Melolonthinae, Rutelinae, Dynastinae, Scarabaeinae, Orphninae, Aphodiinae, Hybosorinae, Bolboceratinae and Omorginae. The highest beetle diversity was recorded in month of June and July. Correlation analysis indicated that rainfall showed positive significant correlation with all recorded subfamilies except Orphninae. The aim of the investigation may be helpful in sustainable pest management strategies.