Push–pull plants in wheat intercropping system to manage Spodoptera frugiperda

The fall armyworm, Spodoptera frugiperda, is one of the most notorious insect pests, and a major threat to maize (Zea mays) and other important crops, such as wheat (Triticum aestivum). Although the push–pull strategy based on intercropping has been reported to effectively prevent damage caused to maize, the potential of wheat-based intercropping systems for S. frugiperda management has rarely been assessed. In this study, the offspring performance, oviposition, and feeding preferences of S. frugiperda on four commonly planted crops—maize, pea (Pisum sativum), faba bean (Vicia faba), and alfalfa (Medicago sativa)—in wheat-based intercropping system were investigated to evaluate the roles of those host plants in the pest management. The results showed that S. frugiperda larvae performed poorly on pea and faba bean plants, as indicated by the longest duration for larval developmental, total pre-oviposition period, and mean generation time as well as the lowest pupal weight and larval survival rate. Lower offspring performance on pea and faba bean leaves coincided with lower efficiency of larval consumption. Preference tests revealed that female adults and larvae exhibited a stronger oviposition on, and feeding preference for maize than wheat, whereas no-preference was observed for faba bean plants. This study revealed the adaptability of S. frugiperda and its preference for wheat and its four common intercropped host plants and provided an insight into the management of S. frugiperda through the establishment of a push–pull strategy in wheat-based intercropping systems.