HISTORICAL EVIDENCE FOR POPULATION DYNAMICS OF TIBETAN MIGRATORY LOCUST AND THE FORECAST OF ITS OUTBREAK*

Abstract The Tibetan migratory locust ( Locusta migratoria tibetensis Chen) is the highest altitude distributed subspecies among the 10 subspecies of migratory locusts. It was discovered and described as new subspecies in 1963. It is mostly distributed above an elevation of 3 000 m, with the highest up to 4 600 m, on the “Roof of the World,” viz. the Qinghai‐Xizang Plateau in southwestern China. Recent study on the historic literature revealed ancient records of locust plagues caused by Locusta migratoria tibetensis Chen in many regions of Xizang (Tibet). These disasters took place during 124 years stretching from 1828 to 1952. Forty‐five places were infested by locust swarms, and from 1846 to 1857 locust disasters occurred sucessively in 12 years, and affected 18 places of Xizang. At the severe disaster regions crops were damaged by locusts in such a degree that there was no harvest at all. At the same time, locust plagues due to another subspecies also occurred in the plains between the Yellow River and Huaihe and Haihe Rivers in East China. The disasters in Xizang were caused by the Tibetan migratory locust, while in Huang‐Huai‐Hai Plain disasters were due to the Oriental migratory locust Locusta migratoria manilensis (Meyen). This study not only provides the evidence that the Tibetan migratory locust has been existing as a separate subspecies with a long history, but also reveals the relevant years of locust plagues, their regional distribution and intermittent rules of locust plagues. It also offers a scientific basis for forecasting Tibetan migratory locust disasters and related monitoring strategies; as well as understanding the close relationship between the outbreak of the migratory locust and drought.