Potential overwintering boundary and voltinism changes in the brown planthopper, Nilaparvata lugens, in China in response to global warming

The brown planthopper Nilaparvata lugens (StAyenl) is a major rice insect pest in China and other Asian countries. This study assessed a potential northward shift in the overwintering boundaries and changes in the overwintering areas and voltinism of this planthopper species in China in response to global warming. Temperature data generated by 15 Global Circulation Models (GCMs) from 2010 to 2099 were employed to analyze the planthopper's overwintering boundaries and overwintering areas in conjunction with three Special Report on Emissions Scenarios (SRES). Planthopper voltinism from 1961 to 2050 was analyzed in scenario A2 using degree-day models with projections from the regional circulation model (RCM) Providing Regional Climates for Impacts Studies (PRECIS). In both analyses, 1961-1990 served as the baseline period. Both the intermittent and constant overwintering boundaries were projected to shift northward; these shifts were more pronounced during later time periods and in scenarios A2 and A1B. The intermittent overwintering area was modeled to increase by 11, 24 and 44 %, and the constant overwintering area, by 66, 206 and 477 %, during the 2020s, 2050s and 2080s, respectively. Planthopper voltinism will increase by < 0.5, 0.5-1.0 and 1.0-1.4 generations in northern, central and southern China, respectively, in 2021-2050. Our results suggest that the brown planthopper will overwinter in a much larger region and will produce more generations under future climate warming scenarios. As a result, the planthopper will exert an even greater threat to China's rice production in the future.