Parasitism success of Microplitis manilae (Hymenoptera: Braconidae) on different diet-fed Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae

Efficient rearing is necessary for the successful biological control of pests. The braconid wasp, Microplitis manilae, is a natural solitary parasitoid of larval Spodoptera frugiperda. However, the effect of the host diet on the parasitism success of M. manilae on S. frugiperda larvae remains unclear. Here, we determined the parasitism rate, oviposition, eclosion rate, developmental period and offspring sex ratio of M. manilae parasitizing S. frugiperda fed with fresh corn leaves or an artificial diet. M. manilae parasitizing the corn leaf-fed S. frugiperda larvae exhibited a significantly higher parasitism rate (40%), oviposition (62.50 eggs/female) and eclosion rate (81.38%) than the wasp parasitizing the artificial diet-fed S. frugiperda larvae (22%, 38.33 eggs/female, and 58.73%, respectively). Furthermore, M. manilae parasitizing the corn leaf-fed S. frugiperda larvae exhibited a significantly shorter developmental period (16.35 days) and lower sex ratio (1.17) than the wasp parasitizing the artificial diet-fed S. frugiperda larvae (18.00 and 2.15 days, respectively). Overall, M. manilae exhibited better parasitic success on corn leaf-fed S. frugiperda larvae than on artificial diet-fed S. frugiperda larvae. Therefore, using fresh corn leaf-fed S. frugiperda is the most suitable strategy for mass-rearing M. manilae for pest biocontrol. Our findings suggest M. manilae as an effective biocontrol candidate for controlling S. frugiperda in corn fields.