Bats are sentinels for invasive pest surveillance based on DNA metabarcoding

Loss of crop yield due to non-native invasive pests is a global phenomenon with profound population, biodi-versity, ecosystem, and economic impacts. The polyphagous and migratory fall armyworm (FAW) Spodoptera frugiperda (Lepidoptera, Noctuidae) has become a major invasive pest around the globe in the past decade, posing a great threat to global food security. Early warning and timely detection of this pest and its associated agri-cultural risks are essential for preventing, intervening, controlling, and mitigating invasion threats, which could reduce crop losses and economic damage. However, one key challenge is how to effectively and accurately monitor pest invasion as soon as possible prior to their establishment. Here, we aimed to determine the effec-tiveness of four different methods for identifying the presence of FAW, namely DNA metabarcoding, field survey, light trap, and sex pheromone trap. We collected fecal samples of six bat species in the FAW colonization area, including Rhinolophus pearsonii, Rhinolophus rex, Ia io, Myotis altarium, Myotis pilosus, and Myotis chinensis. We then utilized bat fecal samples to monitor FAW through DNA metabarcoding during its early establishment stages and compared this approach to three traditional surveillance methods. The results revealed interspecific dif-ferences in the occurrence frequency of FAW in different bat species. Furthermore, bat fecal DNA metabarcoding successfully monitored the occurrence of this pest nearly one month in advance compared with traditional ap-proaches, which coincides with the adult migration time of larval counterparts found in the field based on effective accumulated temperature calculations. Our results showed that DNA metabarcoding dietary analysis of generalist insectivorous bats can be an effective, noninvasive, and economically viable tool for invasion pests monitoring to inform management decisions.