Ecological Diversity and Seasonal Activity of Staphylinid Beetles (Coleoptera: Staphylinidae) as Predators in Rice Fields

Abstract

Rove beetles (Coleoptera: Staphylinidae) are important generalist predators in agroecosystems, contributing significantly to natural pest suppression in rice fields. The present study evaluates the ecological diversity and seasonal activity of staphylinid beetles in rice-based cropping systems and their potential role as biological control agents. Field surveys were conducted across different growth stages of rice, and beetle populations were sampled using standardized pitfall trapping and sweep net methods. Specimens were identified based on morphological diagnostic characters including body shape, elytral length, antennal segmentation, and abdominal flexibility. Results revealed a diverse assemblage of staphylinid species inhabiting rice fields, with variation in abundance and species composition across crop growth stages. Peak activity of staphylinid beetles was observed during the vegetative and early reproductive stages of rice, coinciding with high prey availability and favorable microclimatic conditions. Population density declined during the later stages of crop maturity, likely due to habitat changes and reduced prey abundance. Environmental factors such as temperature, humidity, and soil moisture significantly influenced seasonal activity patterns. The study also indicated a strong association between staphylinid abundance and pest population density, suggesting their role in regulating insect pests in rice ecosystems. Ecological diversity analysis demonstrated that rice fields support a rich community of predatory staphylinids, contributing to overall arthropod biodiversity and ecosystem stability. The findings highlight the importance of conserving predator habitats within rice agroecosystems to enhance natural biological control. Overall, staphylinid beetles represent a valuable component of integrated pest management strategies in rice cultivation due to their predatory efficiency and seasonal adaptability.