Biological control of fall armyworm Spodoptera frugiperda (JE Smith) using egg parasitoids, Trichogramma species (Hymenoptera: Trichogrammatidae): a review

BackgroundFall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an invasive pest that can cause serious crop loss to various important food crops and risk to global food security. FAW can cause damage to over 350 plant species by feeding on vegetative and reproductive stages of crops. Currently, chemical pesticides and transgenic maize are widely used to safeguard crops from this serious pest. However, biological control is a safer and more sustainable alternative in the long term for FAW management. Of the various natural enemies of FAW, egg parasitoids of genus Trichogramma have been used in augmentative biological control of FAW in the Americas and invaded regions such as Africa and Asia.Main bodySeveral species of Trichogramma have been reported naturally parasitizing FAW eggs and emerged as important biocontrol agents. This paper presents a comprehensive review of potential and challenges associated with Trichogramma in biological control of FAW. A total of 11 species of trichogrammatids occurred naturally on FAW eggs. This review includes the occurrence of Trichogramma species on FAW, biological attributes, mass rearing, release techniques, field efficacy and interaction and integration with other parasitoids. Integration of Trichogramma with other parasitoids can resolve the problem related to its penetrative ability against scaled and multi-layered FAW eggs which were discussed.ConclusionInvasion of FAW in Africa and Asia has provided a prospect for augmentative biological control of FAW using Trichogramma for sustainable production, especially in maize which is used as food and fodder. Integrating Trichogramma with safer and selective green pesticides and their conservation with other natural enemies could help in sustainable and environment-friendly FAW control.