Abstract: A mark-release-recapture (MRR) experiment was conducted in June, 2009 in Inner Mongolia Autonomous Region, and the peak for the overwintering adult population of the beet webworm, Loxostege sticticalis L. (Lepidoptera: Pyralidae) was detected in order to demonstrate the migratory pathway and capacity of this species from northern region to northeast region in China. In July, about 1.8 million adults were caught by nets, marked by spraying colorant and released at 6 sites distributed in Wuchuan County (41.07°N, 111.42°E) and Chayouzhongqi (41.13°N, 112.58°E) of Inner Mongolia during June 1st-4th, 2009. At the monitoring and forecasting units of the beet webworm at various levels in the 11 main occurrence provinces or autonomous regions in northern China, methods such as trap lamps, clap nets and pheromone traps were used to recapture the adults of this moth. Nine adults, released at Chayouzhongqi, were recaptured at Keyouzhongqi, Wulanhaote, and Zhalantun County, respectively, in northeastern Inner Mongolia during June 7th-25th, and 1 adult released at Wuchuan County was recaptured at Beipiao County of Liaoning Province on June 29th. The straight distances from the released sites to the recaptured sites were from 725-1 117 km. This is the longest distance taken by the migratory flight of the beet webworm that has been recorded in the world. These results not only prove the soundness of traditional assumption that the beet webworm originated from northern China is one of the sources for the 1st generation of the moth in northeastern China, but also provide important basis to improve the forecast and management technology of the beet webworm.

Key words: Loxostege sticticalis, migration, mark-release-recapture (MRR), migration distance, migration route, overwintering areas