Abstract
The fall webworm, Hyphantria cunea (Drury) (Lepidoptera: Erebidae: Arctiidae), is a highly dangerous global invasive pest. It exhibits two races: the "red-headed" and "black-headed," each with distinct ecological traits. However, much remains unknown regarding the climatic niche and potential global distribution suitability of these two races. This study utilized the COUE framework, and Maxent models to investigate the climatic niche differences between these two races and predict their respective potential suitable distributions globally. Our findings indicate substantial differences in the climatic niches between the two races of H. cunea, with the red-headed race demonstrating greater invasive potential compared to the black-headed race. Both races pose significantly larger potential threats globally than currently recognized. They are capable of survival in North America, South America, Europe, Asia, Africa, and Australia. Specifically, Asia and Europe exhibit potentially greater threats from the black-headed race, while other regions show greater potential harm from the red-headed race. This study highlights significant differences in the climatic niches between the two races of H. cunea, as well as the substantial presence of uninvaded suitable habitats globally for both races. Therefore, future efforts to prevent H. cunea invasions should prioritize control strategies tailored to each race and especially emphasize potential regions that have their respective suitable habitats that have not yet been invaded.