Genetic structure, dispersal pathways, and northern expansion predictions of Solenopsis invicta: A two‐decade journey through China's diverse landscapes

Abstract The red imported fire ant, Solenopsis invicta , has invaded China for over two decades, advancing northwest from Guangdong to the Yangtze River coast at 30.8° N latitude. A decade since the last genetic analysis, this study revisits the species’ genetic structure and invasion trajectory amidst intensifying selective pressures. Through mitochondrial DNA resequencing of 96 samples across 6 Chinese provinces, we identified 2 haplotypes (H5 and H22), with H22 predominating in Zhejiang, the northern limit of our study. Phylogenetic analysis suggests a likely invasion source from Guangdong and Fujian, with long‐distance dispersal facilitated by the horticultural trade, particularly Cycas revoluta . Local dispersal rates varied significantly, with 40 m/year in northern Zhejiang and 118−186 m/year in Guangdong. A regression model ( y = −303.2523 + 10 855.1813/ x ) forecasts a northern expansion threshold near southern Shandong. However, considering the bridgehead effect, repeated invasions, and climate change, the species’ invasive range may extend further north.