Predicting distribution of Piezodorus hybneri (Gmelin) (Hemiptera: Pentatomidae) in Korea under climate change using the Maxent model

Abstract

Piezodorus hybneri (Hemiptera: Pentatomidae) is one of the major soybean pests, and distributed mostly in the southern region in Korea. However, the climate change may change the current distribution of P. hybneri. The species distribution model (SDM) is often used to predict potential distribution of insects. In this study, we used the representative concentration pathway (RCP) 8.5 scenario and the Maxent model, which is one of the SDMs, to predict distribution of P. hybneri in Korea under climate change. Thirty four occurrence points were applied for model calibration, which were collected from specimen data in Jeju and field survey. Occurrence data for model validation were collected from scientific articles and National Ecosystem Survey reports in Korea. To avoid sampling bias, Average Nearest Neighbor distances among occurrence points were calculated using ArcGIS 10.1 and the Rarefy Occurrence Data at SDMs (species distribution models) tool on ArcGIS 10.1 was used. As a result, 12 occurrence points were used for model validation to predict distribution of P. hybneri. By using DIVA-GIS 7.5 19 bioclimatic variables were generated from 2001-2010 (2000s) climate data and 2031-2040 (2030s), 2051-2060 (20-50s), 2071-2080 (2070s), 2091-2100 (2090s) climate data from the RCP 8.5 scenario. Then, these variables were applied to the Maxent model, and through variable selection process, 4 variables were selected: Annual mean temperature, temperature seasonality, mean temperature of wettest quarter and mean temperature of coldest quarter. Finally, by using the Maxent model and these four variables, potential distribution of P. hybneri in current (2000s) and future climate condition was predicted. Among 4 variables, mean temperature of wettest quarter and mean temperature of coldest quarter were most important. In conclusion, following prediction was made for distribution of P. hybneri in Korea. The suitable habitat area for P. hybneri was 20,710 km2 in 2000s, locating in the southern coastal areas and southern part of western coastal areas. Suitable habitats were extended to north-east bound by climate change, as 41,599 km2 in 2030s, 68.404 km2 in 2050s, 83,336 km2 in 2070s and 89,062 km2 in 2090s. In 2090s, most parts of Korea except for the mountain region were suitable for P. hybneri.