Interspecific Competition between Invasive Spodoptera frugiperda and Indigenous Helicoverpa armigera in Maize Fields of China

Since the fall armyworm (FAW) Spodoptera frugiperda invaded China, it has coexisted in maize fields with native cotton bollworm (CBW) Helicoverpa armigera, but population dynamics and competitive mechanisms between two pests are not well understood. We evaluated interspecific competition FAW CBW by analyzing their bidirectional predation laboratory, survival rates when larvae co-infested same plant, of both field. In tests, preyed on each other. However, theoretical maximum sixth-instar preying first–second-instar was 71.4 32.3 individuals, respectively, while that 38.5 28.6 individuals. The field co-infestation trials showed older had a higher rate plants, young larval for than CBW. from 2019 to 2021 southern Yunnan, populations were significantly those Our findings suggested advantage over CBW, which might be an important reason its dominance Chinese fields. This result provides scientific basis developing monitoring technology integrated management habitats FAW.