Local distribution of insect pest population should be changed in near future as well as their host based on climate change scenario. Although well defined insect geographical distribution model is developed and projected its potential establishment in Korea, it has defectiveness without geographical matching of its host, because, in agriculture, insect pest damage is related by host-insect synchrony in time and space. In this study, the possible geographical distributions of two insect species, Corposina sasakii (native species) and light brown apple moth, Epiphyas postvittana (possible invasive species), were estimated by CLIMEX simulation under RCP8.5 climate change scenario. Projected farm land suitability of apple trees was obtained from open website of Fruit Research Division, NIHHS, RDA. All the potential geographical distribution maps were overlapped then the spatial synchrony were analyzed by SADIE (spatial analysis with distance indices) , which allows improved interpretation of the spatial synchrony.

The establishment of insect population in certain region is affected by three major characteristics, the host spectrum, the phenological plasticity and the overwintering strategy. The geographical distribution of insect population is directly affected by their successful establishment in local environment, thus, in case of development of potential geographical distribution models, three major characteristics should be considered carefully. In this study, we developed geographical distribution model using CLIMEX system with well-known insect species, Carposina sasakii. Its geographical distribution is limited to northeast Asia including Korea, Japan, China and the Soviet Far East. C. sasakii overwinters as a full-grown larva within spherical and compactly woven larval-cocoons in the soil. We calculated Diapause Index (DI) then incorporated DI into CLIMEX system to simulate Ecoclimatic Index (EI), which stands for ability of establishment in a certain area for further studies of geographical distribution of insect populations which have overwintering strategy in their life history.