Spider (Arachnida, Araneae) diversity and distribution in the Gandhigram Rural Institute campus, Dindigul district, Tamil Nadu, India

Abstract

Spiders are key arthropod predators that regulate insect populations and respond sensitively to habitat heterogeneity, making them effective indicators of ecosystem condition. This study assessed spider diversity, distribution, and functional guild structure across six habitat types within the Gandhigram Rural Institute (GRI) campus, Dindigul district, Tamil Nadu, India. A total of 61 species representing 5,719 individuals, 19 families, and 46 genera were recorded during a three-month survey (January 2025 – March 2025), during the dry season. Salticidae was the most species-rich family, while Oecobiidae, Pholcidae, and Lycosidae were numerically dominant. Alpha diversity varied among sites, with highest richness and Shannon diversity observed in heterogeneous agricultural habitats, whereas built-up areas exhibited greater dominance. Moderate beta diversity (Whittaker = 0.64126; Bray-Curtis similarity) reflected species turnover across contrasting microhabitats. Gamma diversity indices (H’ = 3.053; 1–D = 0.9341) indicated a diverse and stable campus-wide assemblage. Diurnal and nocturnal sampling revealed comparable richness, highlighting complementary activity patterns. Guild analysis demonstrated functional diversity dominated by active hunters and web-builders.