The objective of this research was to determine the cause of the continuous outbreaks of brown planthopper( BPH) in Taihe County. We analyzed field and light trap data on BPHs in Taihe County from 2008 to 2013,and combined them with data on meteorological conditions to identify the main reasons for the outbreaks in late-rice fields. The BPHs damaging early-rice fields were the 2~(nd) and 3~(rd) generations whose population sizes were mainly limited by early immigration.After the early-rice harvest,resident ...