The occurrence of Tuta absoluta in southwest China and its spreading front to central and South China

The aim of this study was to investigate the geographical distribution and the spread front of Tuta absoluta in the southwest, central and southern parts of China through a field survey, and to find out the distribution of T. absoluta in southwest China and its spread to neighboring provinces. The survey covered 192 townships in 100 counties in the provinces of Yunnan, Guizhou, Sichuan, Chongqing, Xizang, Hubei, Hunan, Guangxi Zhuang Autonomous Region and Guangdong Provinces (municipalities directly under the central government and autonomous regions). The results showed that T. absoluta occurred in 12 townships in 10 counties of Yunnan Province, 25 townships in 13 counties of Guizhou Province, 19 townships in 11 counties of Chongqing Municipality and 4 townships in 3 counties of Guangxi Zhuang Autonomous Region. In Sichuan Province, 30 counties and 47 townships, 22 counties and 33 townships found T. absoluta distribution; in Hubei Province, 7 counties and 16 townships, 5 counties and 11 townships found T. absoluta distribution; in Hunan Province, 20 counties and 53 townships, 10 counties and 24 townships found T. absoluta distribution. In 2 counties and 4 townships in Tibet Autonomous Region and 4 counties and 12 townships in Guangdong Province, only one township was found to be affected by the T. absoluta, which was the Naxi ethnic township in Mangkang County, Chamdo City, Xizang Autonomous Region, and the Sanshui Yao Township in Lianzhou City, Qingyuan City, Guangdong Province, respectively. This survey clarified the distribution area of T. absoluta in the southwest region and the frontiers of its spread to the surrounding provinces, and provided data reference for the monitoring and early warning of T. absoluta as well as the scientific prevention and control of T. absoluta.