Research progress on host plant adaptation of fall armyworm (Spodoptera frugiperda) in China, and the potential risk to forage grasses

Fall armyworm, Spodoptera frugiperda (J. E. Smith), a major invasive pest that has seriously threatened food security in China. It invaded China from Myanmar in December 2018 arriving in Yunnan Province, and was officially listed at the top of the "Category Ⅰ Crop Diseases and Pest " in 2020 by the Ministry of Agriculture and Rural Affairs. The fall armyworm has a wide host range; its larvae can feed on and damage up to 353 plant species from 76 families, primarily from Poaceae, Asteraceae and Fabaceae families. The fall armyworm in China is a non-typical corn-type population. It is a hybrid between the rice strian (maternal) and corn strain (paternal), which exhibits certain level of hybrid vigor, potentially posing an enhanced threat to a broader range of plants. This review systematically summarizes four key aspects: (1) the major and common plants are susceptible to fall armyworm in China, (2) the currently known host plant species of fall armyworm in China, (3) the host adaptation mechanism of fall armyworm, (4) the adaptive evolution and potential threat by this invasive hybrid type to forage grasses, rice and other plants in China. The paper can provide reference for future research on the host adaptation to forage grasses and other grassland plants of fall armyworm.