Impact of Habitat Fragmentation on Reduviid (Hemiptera: Reduviidae) Diversity and Predation Dynamics in the Southern Western Ghats of Tamil Nadu, India

Climate change is expected to significantly impact biodiversity, including predator-prey interactions. This study investigated the distribution and diversity of reduviid predators (Reduviidae), potential biocontrol agents of agricultural and forest insect pests, across three distinct habitats in the Southern Western Ghats, Tamil Nadu, India, over 12 months. Understanding baseline diversity and distribution is crucial for predicting climate change impacts. A total of 641 individuals, representing 7 sub-families, 24 genera, and 31 species were recorded from the Killikulam semi-arid zone (SAZ), Aralvoimozhi scrub jungle (SJ), and Godayar tropical forest (TF). Species richness was highest in the SJ (22), followed by the SAZ (13) and TF (9). Seasonal variations in predator populations were observed, with peaks during winter in the SAZ, summer in the SJ, and also summer in the TF. The dominant reduviid species were Edocla slateri and Rhynocoris fuscipes (50%), followed by Acanthapis pedestris and Catamirus brevipennis (44.4%) and Irantha armipes (38.9%). These dominant species, potentially valuable for pest management, may exhibit varying responses to changing climatic conditions. The SJ exhibited a higher Shannon-Weiner index (2.552) than Simpson’s index (0.146), indicating greater diversity. While specific prey populations appear to influence the distribution of certain reduviid species, regardless of habitat, future research should investigate how climate change-induced shifts in temperature, rainfall patterns, and prey availability might alter these relationships. This baseline data is essential for developing climate-smart conservation strategies for reduviid predators and ensuring their continued effectiveness as biocontrol agents in the face of climate change.