Abstract:  The white-backed planthopper (WBPH), Sogatella furcifera (Horváth), is a serious pest of rice in South China including Fujian Province. The earlier huge immigration peaks of WBPH had been seen from April to May 2007. In this study, HYSPLIT (Hybrid Single-particle Lagrangian Integrated Trajectory), a trajectory analysis platform developed by the National Oceanic and Atmospheric Administration (NOAA) of US and Australian Bureau of Meteorology, was used to simulate the early migratory pathways of WBPH from their source areas in April and May from 2007 to 2010. GrADS (Grid Analysis and Display System), a meteorological data analysis and displayed software, was used to analyze and display the synoptic meteorological background during the early immigration periods in May 2007. The results showed that: (1) the source areas of the earlier mass immigration population of WBPH occurred from 2007 to 2010 were mostly in Guangdong and Hainan Provinces, and a few sources were from Taiwan Province and Philippines. (2) The co-occurrence of low-level jet and continuous rainfall directly resulted in the concentration of the airborne migrants and the mass immigration of WBPH in 2007. During the appearance of major immigrants in May, 2007, there were strong southwest lowlevel jets at 850 hPa simultaneously. Meanwhile, the West Pacific subtropical high was stronger than normal and extended towards west, and the northern jump of its ridge postponed, that caused the formation of a stationary front in South China and brought the sustained rainfall. (3) The high early-immigration of the 1st generation of WBPH from late March to early April in Guangdong and Hainan, and their high offspring population of the 2nd generation bred during March to May in 2007 was the key reason for mass immigration in Fujian. It is assistant to the forecasting and management work for rice planthopper in Fujian Province to investigate the rice planthopper situation in Hainan, Guangdong and Guangxi, in more rain and stronger West Pacific subtropical high years.

Key words: White-backed planthopper (Sogatella furcifera), migration, light trap catches, source area, trajectory analysis