Insect diversity in a patchy rice paddy ecosystem

Department of Plant Protection, Faculty of Agriculture, University of Bengkulu, Indonesia

Abstract

Insect diversity in rice agroecosystems is influenced by various factors, including geographical location, elevation, and surrounding habitats. This study aimed to assess insect diversity in apatchy rice paddy ecosystem. The rice cultivation system applied was conventional, with pest management primarily relying on chemical insecticides. The study area covered 6.000 m² and consisted of 10 terraced plots. The rice variety used was Inpari Cikebo, planted at a spacing of 20 × 20 cm. Sampling was conducted using a stratified random sampling method across each terrace. Insects were collected using three techniques: manual collection, sweeping net, and yellow sticky traps. The results showed that insect diversity comprised 8 orders and 20 families, with a total of 1.938 individuals recorded. The Shannon-Wiener diversity index indicated moderate diversity across sampling methods (manual: H' = 2.55; sweeping net: H' = 2.63; yellow sticky trap: H' = 1.55). The dominance index was low (manual: C = 0.09; sweeping net: C = 0.08; yellow sticky trap: C = 0.28), suggesting that no single species dominated the community. The evenness index was high (manual: E = 0.92; sweep net: E = 0.93; yellow sticky trap: E = 0.67), indicating a relatively uniform distribution of individuals among species.