Migratory insect pest population migrate from the southern China to Korea through jet streams. In Korea, 5 major migratory insect species are important, i,e. Nilaparvata lugens, Sogatella furcifera, Laodelphax striatellus, Mythimna separata and Cnaphalocrocis medinalis, which give damages to the major crops, rice.
Appropriate spatial distribution analysis helps to pest management strategy in order to monitor and develop appropriate sampling plan and control methods. Classical spatial analytic methods, such as Taylor’s Power Law (TPL) and Iwao’s Patchiness Regression (IPR), sometimes can not differentiate different spatial distribution. Geostatistics is a part of statistics that focuses on the detection, modeling and estimation of spatial patterns. Geostatistics can analyze estimated dispersion and spatial distribution after migration of target species. Spatial Analysis by Distance IndicEs (SADIE) among geostatistics was used to analyze migratory insect pests. SADIE explains spatial variation, spatial distribution of ecological information based on spatial location information.
This study was conducted from last July 2016 to early September 2016, from July 2017 to August 2017 and from July 2018 to August 2018 in rice paddy of Jeolla-province. M. separata and C. medinalis collected using sex pheromone traps, while N. lugens, S. furcifera and L. striatellus collected using 3 methods (visual surveys, sweeping surveys, sticky traps). SADIE calculate index of aggregation () and index of clustering ( and ) using quantitative data with co-ordination data. Calculated indices were used to investigate the spatial distribution and red-blue plot analysis of target insect species.
As a result, M. separata and C. medinalis showed different distribution based on SADIE spatial aggregation analysis and red-blue plot analysis. Initial spatial distributions of L. striatellus and other planthoppers were differed among different sampling locations and time.