The invasive fall armyworm, Spodoptera frugiperda, in Africa and Asia: responding to the food security challenge, with priorities for integrated pest management research

In sub-Saharan Africa (SSA) and several Asian countries, maize continues to be a major staple food for millions of people. It plays an important role in food and nutrition security and as a source of income. Pests and diseases, however, are the primary biotic constraints to maize productivity in these countries. The recent invasion of the fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), throughout Africa and Asia threatens the production and food security goals of subsistence smallholder farmers throughout most of sub-Saharan Africa followed by spread to India in 2018 and China. FAW was first detected in West Africa from São Tomé, Nigeria, Bénin and Togo in early 2016. As of May 2019, FAW has now been confirmed in all sub-Saharan countries, and later on its occurrence has been reported in various Asian countries. FAW is a highly polyphagous pest attacking over 350 plant species, including several economically important crops such as maize (Zea mays L.), rice (Oryza sativa L.), cotton (Gossypium spp. L.), sorghum (Sorghum bicolor (L.) Moench) and several legumes that are also preferred hosts. In Africa, without effective FAW management options, this pest will cause substantial maize yield losses ranging from 8.3 to 20.6 million tonnes annually, with losses of $2.5–6.2 million. However, now that FAW is established in > 42 countries, the total annual impact is estimated at $13 billion. Although over 150 species of FAW parasitoids have been recorded in the Americas, there is still the demand of information regarding the potential of biological control in Africa, and alternative complementary management tactics. Given the ongoing damage potential of FAW in Africa, and now Asia, the urgency to develop practical management solutions at the farm level cannot be overemphasized. This review summarizes much of the global, current research that should be useful in developing FAW management programs for smallholder farmers in SSA and Asia. In so doing, we present an Integrated pest management (IPM) framework that relies on several foundational and compatible tactics, including timely monitoring of FAW, host plant resistance, biological control, cultural control, and when necessary, chemical control. Consequently, this review identifies several research gaps, as well as logical research objectives that should prove useful going forward. Finally, we explore how sustainable IPM systems for FAW can contribute to both long-term food security and environmental stewardship goals for agricultural production in sub-Saharan Africa and Asia-Pacific region.