Biochemical and Morphological Mechanisms Underlying the Performance and Preference of Fall Armyworm () on Wheat and Faba Bean Plants.

(J. E. Smith), which attacked China in 2019, remains a significant threat to wheat production. Wheat-faba bean intercropping systems prevent damage caused by wheat aphids; however, the potential role in control remains unclear. Here, the adaptability and preferences of to wheat and its common intercropped plant, faba bean, were evaluated to implement an eco-friendly approach for management. Their adaptability showed that both hosts could support to complete their life cycle; however, the larvae performed worse on faba bean compared with on wheat. The biochemical analysis revealed that faba bean plants had lower contents of soluble sugars and total proteins but higher levels of phenolics and tannins than in wheat leaves. The gravid preferred (during the preference assays) to oviposit on wheat rather than on faba bean plants in cage tests. The wheat odor was preferred over the faba bean odor in the Y-tube olfactometer bioassays. The morphological scanning electron microscopy (SEM) showed increased trichome density on wheat leaves. Therefore, the faba bean plants displayed antibiosis on larvae and were repellent to female moths, thus, suggesting that faba bean plants could serve as a push crop to be intercropped with wheat for control for wheat fields.