| White-backed planthopper(Sogatella furcifera),as a major rice insect pests,have frequently broken out in recent years and cause serious damage to rice production in China and some other countries. It has the damage characteristics of "explosive, migratory, international, devastating".There are about 4-5 northward migration processes and 3-4 southward migration processes of white-backed planthopper in our country every year. In winter, it damages slightly only in south of Guangxi,Guangdong,Yunnan, Hainan Island and other tropical areas; In early spring, a large number of white-backed planthoppers(WBPH) immigrate to our country from southeast Asia with the developing of monsoon and damage the rice of south China; In late spring and early summer, it migrates northwards and land to destroy the rice in Yangtze Area; In late summer, it migrates back and does harm to the rice distributes widely in China. This harmful and seasonal migration causes immeasurable loss to rice.To study the migration process of white-backed planthopper, besides its physiological and ecological mechanism, we need to observe the environment background, especially the atmospheric background. Monitoring and early warning is the footstone for effective prevention and control. With the development of society, the new technologies such as insect radar and meteorological model contribute a lot to the prevention and control. In order to clarify the small-scale insect source of immigration population of WBPH and the relationship between its migration process and atmospheric background.From 2012 to 2015,we have monitored the occurrence of WBPH continuously with light trap, in Xingan County, Guangxi Province. A large-scale immigration events of white backed planthopper which was occurred in mid-June 2012, in China’s Northern Guangxi rice was selected to be analyzed, using a new generation scale meteorological forecast forecast WRF model to analyze its meteorological background, and using the Lagrange particle analysis tool- FLEXPART model to simulate its trajectory. The main findings are as follows:1. In the 4th to 10 th June, in 2012 migration process, was analyzed topographically under the assistance of ArcGIS10.0.Based on this time-space-distribution analysis, a model with the high tempo-spatial resolution,WRF model were used to simulate the weather background of this process and analyze the horizontal wind field, temperature field, vertical velocity field,vorticity field, vorticity field selected from the output of the high tempo-spatial resolution atmospheric background.We found that the low-level jet as carrier air of WBPH affected the migration process and sinking airflow and temperature barrier made the white-backed planthopper landed intensely. Sinking airflow and high temperature are good for WBPH populations to land. There is sinking airflow in the anti- cyclone curve of horizontal flow field, negative vorticity region, positive divergence region and positive zone of vertical airflow field. These area fitted this insect area.2. We simulated the trajectory of this migration process with FLEXPART-WRF model which was derived by high tempo-spatial resolution atmospheric background file- NetCDF file, and imported trajectory points into Arc GIS10.0. From the trajectory simulation, we found the main source is located in the southern region of northeast, Indochina in Guangdong and GuangXi. The nutritional conditions made sogatellafurcifera move north with airflow in the ripening stage of rice. |
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