Effect of meteorological conditions on migration and occurrence of two migrant insects in rice fields of Yongfu County.

[Objective]The present study was conducted to analyze the effect of meteorological conditions on two migrant insects in rice fields of Yongfu County, Guangxi, in order to develop control and prevention measures for migrant insects. [Method]The meteorological conditions of the affected area were investigated and their effects on migration of insects in Yongfu County during 2006-2010 were analyzed. [Result]The migration of two insects clearly showed their relations to the seasonal changes, they migrated from the south to the north in spring and summer, and from the north to the south in autumn and winter. Their movement from one place to other was mainly found to be influenced by temperature, which was closely related to migration height. The centralized migration height of rice plant hopper was 500-2000 cm, while that of rice leaf roller was about 800 cm. The adults migrant insects were found to have tendency to light, tender green and wet environmental conditions. The migration path and speed of the insects were found to decide by the wind direction and its velocity, respectively. The major population of the rice plant hoppers (90.5%) mainly found to fly in 20 min before sunset in the dusk. [Conclusion]The basic meteorological conditions, viz., temperature, subsidence, temperature, rainfall, humidity, wind direction and velocity, light illumination, etc., affected the migration of insects in rice fields of Yongfu County. Temperature was the main factor for deciding fly of insects, rainfall and subsidence forced the insects landing, the migration direction and speed of insects were most affected by the winds, and illumination influenced the suitable time for the migration of insects.