Abstract: 【OBJECTIVE】Red imported fire ant (RIFA) Solenopsis invicta Buren, a famous dangerous alien species in the world, was found to infest firstly at Wuchuan, Guangdong, China mainland in Sept., 28, 2004. It distributed at more than 30 counties and infested at 27 thousand hm2 late 2005. It had already caused serious damage to agriculture, human heath and living in the pest infesting area. Invasion and expansion of RIFA were paid important attention to, and location and long-distance expansion regulation of RIFA had been revealed in North America. After found to infest in south China, those problems that when it was introduced in different regions and how about expansion speed were important to resolve.【METHOD】In our study, most of 4 parameters of more than twenty invading cases were collected and analyzed, and the introducing time and expansion regulation of different cases were revealed according to the models that had been built up.【RESULTS】About 10 years ago, RIFA was introduced and located the first time in China mainland, and it infested earlier in Shenzhen, Guangzhou and Wuchuan, then other regions. Currently, the spatial distribution appeared obviously in type of 2-2-2, including two large blocks, two small blocks and two skipping spots. One large block was composed of Zhujiang river delta, Huizhou and Heyuan, the other Wuchuan, Yangchun, Gaozhou, Dianbai and Maogang. Two little blocks included Xinluo, Shanghang, Dapu and Cenxi, Luchuan, Beiliu respectively. Nanning and Zhangjiajie were the two skipping spots in geography. According to COI gene diversity, introduction time and geographical distribution, RIFA was introduced through more than two ways, more than one spot and one time. Quantity of counties infested by the RIFA in south China was significantly correlative to the duration after introduction, and the models were presented as Y=1.8746x1.1946 and Y=3.6217X1.0559. Quantity of counties infested in going-on decades was forecasted to be 50~60 in 2010, 200~230 in 2045, and the increasing speed was 4~5 counties per year. The expansion speed was shown to be 33.6 km per year and 98.3 km per year respectively by the methods of square root of acreage and beeline distance. The expansion speed was 80 km per year.【CONCLUSION】The duration for invasion of RIFA into south China was about 10 year, the districts infested were more than 30, and the expansion speed was about 80 km per year.

Key words: Solenopsis invicta Buren, introduction history, expansion speed, South China