Strain-Dependent Performance of Spodoptera frugiperda on Cabbage

Abstract

The invasion of fall armyworm, Spodoptera frugiperda, originating from the Americas, into numerous provinces of China has emerged as a significant threat to the nation's grain crop production. Other than crops, will S. frugiperda be a threat to vegetable crops in China? Here, we firstly surveyed the occurrence of S. frugiperda in cabbage field in Jiangsu province, China, and then, we detected the strain composition of the natural population on cabbage; after that, we compared the performance of all the field strains on cabbage in the lab. In 2021, S. frugiperda was found in field cabbage in three sites in Jiangsu province, and there were three strains, namely COIcorn-Tpicorn strain (COICS-TpiCS), COIrice-Tpicorn strain (COIRS-TpiCS) and COIrice-Tpirice strain (COIRS-TpiRS); the dominant strain in Haian and Luhe was COICS-TpiCS and COIRS-TpiCS, respectively. Further investigation on the performance of the three strains on cabbage leaves showed that both the survival rate of larvae and the fecundity of the strain COIRS-TpiCS were significantly higher than that of the other two strains, whether fed on seedlings or ball leaves, which showed divergent performance among the three strains on cabbage. These findings underscore the potential threat posed by S. frugiperda to vegetable production in China.