关键词: 提取方法, 提取方法

Abstract: In order to determine the immigration trajectory and source areas of rice planthopper in Guangdong Province, and to establish a basis for refined forecasting and source suppression, the geographic distribution of the source area of early immigrant rice planthopper was analyzed by GrADS (Graphics Processing Software), HYSPLIT-4, a trajectory analysis software for the simulation of migration pathways, and light trap catch data from 2 plant protection stations (including Qingxin, Panyu). The results indicated that precipitation was observed the immigrant and peaks days, as well as one day and two days ago. Downward airflow and precipitation were main two reasons of forcing rice planthopper to land focusly. The peaks of early immigrants of rice planthopper were from early May to early July for early-rice growth reason. Lower jet, southwest and south flows provides carrying force for immigrant rice planthopper, and most of the early immigrants came from Vietnam, southern Laos, Hainan Province, southern Guangdong Province and Guangxi Province. The peaks of early immigrants of rice planthopper were from early September to early October for late-rice growth reason. Rice planthopper was back moved from north to south with north flow, and source of immigrant insect was distributed in the rice areas of Hunan and Jiangxi etc.