RJOAS, 1(109), January 2021 93 DOI https://doi.org/10.18551/rjoas.2021-01.12 PREDATOR DIVERSITY AS NATURAL ENEMIES OF INSECT PESTS ON PADDY FIELD ECOSYSTEM IN PIDIE AND PIDIE JAYA REGENCIES, ACEH PROVINCE, INDONESIA Munawar Master’s Program of Agroecotechnology, Faculty of Agriculture, Syiah Kuala University, Banda Aceh, Indonesia Husni, Jauharlina* Department of Plant Protection, Faculty of Agriculture, Syiah Kuala University, Banda Aceh, Indonesia *E-mail: ljauharlina@unsyiah.ac.id ABSTRACT This study aims to determine the diversity of natural enemies, especially predatory arthropod found in farmers' paddy fields in Pidie and Pidie Jaya Regencies, Aceh Province, Indonesia. The research samples were taken 3 times at the age of 30, 45, and 60 days after transplanting (DAT). Parameters observed included identification of predator morphospecies, the abundance of predator individuals, also diversity, evenness, dominance, and similarity indices of predators. The results showed that the number of predator morphospecies and the abundance of individual predators in paddy rice in Pidie Jaya Regencies tended to be higher than those of paddy field in Pidie Regencies. The index value of predatory diversity in paddy fields in the two regencies was in a good category where the community ecosystem conditions were more stable. The evenness index of predatory evenness in the observation 30 and 45 DAT in the two regencies was in a good category with more stable community ecosystem conditions, but at 60 DAT observations in the two regencies, the index value of the evenness was even in an excellent category with very stable community ecosystem conditions. The dominance index value of paddy fields in the two regencies was a low category (<0.5), meaning predator morphospecies were very diverse. Observations on the similarity index of predator morphospecies showed that the level of community similarity between the two regencies was 0,76 based on the Kendeigh index value. This showed that there were about 76% of the same predatory morphospecies in Pidie and Pidie Jaya Regencies. KEY WORDS Arthropods, insect sampling, rice, biological control. Rice (Oryza sativa L.) is the most essential food crop in Indonesia because more than half of Indonesia's population consumes rice produced from paddy plants. Rice is an annual crop making its ecological conditions keep changing and causing an unstable balance between pest populations and natural enemies (predators, parasitoids, and pathogens). A break in the planting period frequently happens in seasonal crops which will result in no development of natural enemies and pests to increase continuously without any limiting factors from nature (Azmi et al., 2014). Cultivation of rice, which is often monoculture, can encourage paddy field ecosystems that are vulnerable to plant pests (OPT). One of the drivers of the increase in plant pests is the continuous availability of food at all times and in every place (Altieri et al., 2004). The problem faced by farmers nowadays is how to control the plant pests (OPT) properly and safely. The control by using synthetic pesticides can reduce yield losses due to pests, but also cause negative impacts on the environment such as killing natural enemies causing the pest population increases (Herianto et al., 2015). The utilization of natural enemies is one of the ways of controlling pests in a biological way that can minimize the pest population. Biological control means controlling by exploiting natural enemies such as