Abstract: To understand the seasonal host transfer pattern and migration ability ofLygus pratensis in southern Xinjiang oasis cropland, we measured the retention time and content change of Rb in alfalfa and Lygus pratensis bodies with spraying 2000 mg·L^-1 RbCl solution for different times of treatment. Through spraying RbCl in main source regions (alfalfa field), we monitored the regularity and distance of Lygus pratensis migration into cotton field in spring, and the host transfer pattern in spring and autumn. The results showed that spraying RbCl solution for two times effectively increased Rb content in alfalfa and Lygus pratensis bodies, and that Rb persisted in the insect bodies and host plant tissues for at least 10 days. In alfalfacotton adjacent model, Lygus pratensisadults moved at least 750 m from main source regions to cotton field in spring, with a positive relationship between population density and the distance of migration to cotton fields. Lygus pratensis mainly moved from alfalfa fields onto Chenopodium glaucum, safflower, sunflower and cotton in spring, and mainly from cotton fields onto Chenopodiaceae weeds in autumn. These results help us understand the movement and diffusion pattern of Lygus pratensis in oasis croplands, providing a direct basis for monitoring population dynamics and migration of Lygus pratensis in different seasons and important guidance for comprehensive control and ecological regulation of Lygus pratensis in cotton fields.

Key words: Lygus pratensis, Rb-marking, host transfer, migration capacity, southern Xinjiang.