Effect of refugia on spatial and temporal distribution of arthropods on rice agroecosystem (Oryza sativa Linn.)

Abstract

Background and Objective: The arthropods distribution is influenced by several factors i.e., vegetations (refugia). Spatial and temporal distributions can be observed to determine the arthropod's abundance on fields. The research aimed to determine the effect of refugia on the spatial and temporal distribution of arthropods on rice fields. Materials and Methods: From February-April, 2016, farmers' fields in Watugede, Singosari, Malang was observed to collect data and arthropod identification was conducted in Plant Pest Laboratory, Department of Plant Pest and Disease, Faculty of Agriculture, University of Brawijaya. The spatial and temporal distributions of arthropods on rice agroecosystem were investigated by using several observation methods such as visual methods, pit-fall and yellow sticky traps. Observation of spatial distribution was divided into 6 points with 3 replications. The points were 3, 6, 9, 12, 15 and 18 m from refugia. The observation of temporal distribution was done at four periods: Vegetative I, vegetative II, generative I (reproduction) and generative II (ripening) with 18 points of observation in total. Results: The results showed that the spatial distribution of arthropods on the field at the 3 m observation point which is the closest observation point to the refugia has the highest abundance of arthropods. While, the lowest found at the 15 m observation point from the refugia. Temporal distribution of arthropods on the field showed that the highest number occurred in the vegetative II and the lowest in the vegetative I. Conclusion: Based on temporal and spatial distributions on rice farm, the highest abundance of arthropods are determined in the vegetative II and 3 m observation point.