Abstract:

【Objective】 Research on the variation of light catch and population status of the clover cutworm Scotogramma trifolii (Lepidoptera: Noctuidae) was carried out in order to provide a basis for effective prevention and control of it in North China. 【Method】 Vertical-looking radar and related equipment were used to carry out real-time monitoring of the migratory process of the clover cutworm, and the prevalent airflow was analyzed by the software of GRADS during the migrating peak and the Hysplit_4 software was employed for analyzing their migratory trajectory. Population status of the overwintering generation moth was also discussed. 【Result】Ovarian development concentrations at 2-3 grade and the sex ratio＞1 during moth occurrence peak period, but the sex ratio＜1 after the peak period. Simultaneous radar observations indicated that the nocturnally migrating clover cutworm mothes generally flew at altitudes of up to 600 m above ground level, with high density concentrations at about 300-500 m and these concentrations were coincident with favorable wind direction and wind speed. They can take 8 h sustainable flight in one night. Trajectory analysis of 12 h also showed that most of them came from Eerduosi, Huhehaote, Wumeng and other regions. in Inner Mongolia and some from north of Shaanxi and Shanxi provinces, migrated and diffused into northeast and southeast with the westerly airflow. 【Conclusion】 The overwintering generation of clover cutworm moth has a typical migratory habit, and it is of a great significance for eatly monitoring and forecasting them according to their migratory behavior.

Key words: Scotogramma trifolii, migration, radar observation, population analysis