Evaluating wetland health using Odonata diversity and seasonal shifts in Tulshi Reservoir, Maharashtra, India

Abstract

The study assesses species composition and seasonal variation of odonates at Tulshi Reservoir in Kolhapur district, northern Western Ghats, Maharashtra. Field surveys were carried out during pre-monsoon, monsoon, and post-monsoon seasons through direct observations and photographic documentation. A total of 32 species belonging to two suborders (Anisoptera and Zygoptera) and four families (Libellulidae, Gomphidae, Platycnemididae, and Coenagrionidae) were recorded, with Libellulidae being the most dominant. Species richness peaked in the post-monsoon season, likely due to improved water quality and enhanced aquatic vegetation. Generalist taxa such as Trithemis aurora (Burmeister, 1839) and Pseudagrion decorum (Rambur, 1842) occurred throughout the year, whereas certain species, including Amphiallagma parvum (Selys, 1876), appeared only in specific seasons. These findings emphasize the ecological importance of Tulshi Reservoir in sustaining odonate diversity and support the use of these insects as effective indicators of wetland health.