Determination and first record of Tuta absoluta in Xizang

From June to July 2024, during greenhouse in Linzhi City (Tsatsum Town) and filed surveillance in Changdu City (Karuo Town and Rumei Town), Xizang, China, we successively found serious infestations of lepidopteran larvae on tomato and potato plants, with mined leaves and attacked fruits. The lepidopteran was identified as Tuta absoluta (Meyrick) using morphology and molecular methods, a major agricultural invasive pest in China. It is the first report that T. absoluta occurred in Xizang, China. In this paper, the morphological characteristics of T. absoluta and its infestation characteristics in Xizang are described. The possibility that the South American tomato leafminer could be introduced into Xizang via India through international trade in agricultural products, or from some domestic regions where the pest has already occurred (Sichuan, Yunnan, etc.) through seedling transportation was discussed and the spread trend was studied and judged. Currently, it is evident that the diffusion trend of T. absoluta is from low-altitude to high-altitude in Xizang. Therefore, in order to prevent the continued introduction and diffusion hazard of the pest, it is necessary to strengthen the inspection and quarantine on agricultural product trade and seedling transportation to block dispersion pathways of T. absoluta, and timely and comprehensive survey of the pest in the entire region, including clarifying its main occurrence regularity, degree of damage, and distribution range and so on, which provides reference for monitoring and controlling agricultural invasive species in Xizang.