Potential distribution of fall armyworm in Africa and beyond, considering climate change and irrigation patterns

Bipana Paudel Timilsena,Mark Wamalwa,Henri E Z Tonnang,Saliou Niassy,Irmgard Seidl-Adams,Edwin G Rajotte,Emily Kimathi,Sevgan Subramanian,Sunday Ekesi,Elfatih M Abdel-Rahman,David P Hughes

doi:10.1038/s41598-021-04369-3

Abstract

The fall armyworm, Spodoptera frugiperda (FAW), first invaded Africa in 2016 and has since become established in many areas across the continent where it poses a serious threat to food and nutrition security. We re-parameterized the existing CLIMEX model to assess the FAW global invasion threat, emphasizing the risk of transient and permanent population establishment in Africa under current and projected future climates, considering irrigation patterns. FAW can establish itself in almost all countries in eastern and central Africa and a large part of western Africa under the current climate. Climatic barriers, such as heat and dry stresses, may limit the spread of FAW to North and South Africa. Future projections suggest that FAW invasive range will retract from both northern and southern regions towards the equator. However, a large area in eastern and central Africa is projected to have an optimal climate for FAW persistence. These areas will serve as FAW ‘hotspots’ from where it may migrate to the north and south during favorable seasons and then pose an economic threat. Our projections can be used to identify countries at risk for permanent and transient FAW-population establishment and inform timely integrated pest management interventions under present and future climate in Africa.

Highlights

The fall armyworm, Spodoptera frugiperda (FAW), first invaded Africa in 2016 and has since become established in many areas across the continent where it poses a serious threat to food and nutrition security
The result shows that most of the world’s tropical and subtropical climates are climatically suitable for year-round FAW establishment (Fig. 2a)
The model projected a notable difference in the potential distribution of FAW between irrigation scenario-II and the rainfed scenario, especially in North Africa, the Middle East and Australia (Fig. 2c,d)

Summary

Introduction

The fall armyworm, Spodoptera frugiperda (FAW), first invaded Africa in 2016 and has since become established in many areas across the continent where it poses a serious threat to food and nutrition security. Our projections can be used to identify countries at risk for permanent and transient FAW-population establishment and inform timely integrated pest management interventions under present and future climate in Africa. The choice and scaling of these alternative solutions depend on accurate characterization of the potential permanent and temporal distribution of FAW across the continent as well as how FAW and the agriculture production system will respond to a changing climate Such information will refine our understanding of the pest’s potential migratory behavior in Africa, and is essential for developing long-term strategies to mitigate FAW infestations in hotspots (regions where FAW is endemic) as well as transient areas where FAW may move from hotspots to occupy a region for a period of favorable climate conditions. The rapid spread of FAW across the world may be due to trade and weak phytosanitary regulations, and due to migratory behavior of the pest itself[25–28]

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Results

Discussion

Conclusion