Mapping and forecasting of fall armyworm pest distribution in East Africa using climate information

Abstract

Fall Armyworm (FAW) is among the major pests that destroy important food crops. With origins in the Americas, it was first detected in West Africa in 2016 and has since spread rapidly to other African countries and other continents. Studies have investigated FAW behavior and distribution, however, studies of how climate change may affect FAW suitability have been poorly explored. Reports on how FAW prediction is likely to spread in African countries that lack advanced technologies and practices to prevent the pest could be an approach that enables decision-makers to adapt and take control measures in areas at risk. In this research, we identified the climatic factors that influenced the incidence of FAW pest, and mapped and predicted its suitable habitat in the eastern African region. Findings revealed that five variables had the greatest impact on the performance of the model, among 19 bioclimatic variables. With a contribution of 37.8%, the annual precipitation had the most influence, followed by the annual mean temperature which contributed 13%. FAW potential distribution was also predicted under current climatic conditions, (1970–2000), and for future climate change scenarios, SSP1-2.3, SSP3–7.0, and SSP5-8.5, for the periods 2021–2040 (near term), 2041-2060 (mid-term) and 2061–2080 (long-term). This study showed that in the current climatic conditions, most of the area under study is suitable for FAW incidence and that in the future, this suitable habitat will increase northwards and decline in the southern region. Control and monitoring measures should be adopted to prevent the spread and excess damage of the FAW pest in the eastern Africa region. Studies utilizing different climate models, SSP scenarios, and different periods should be the focus of future research. Understanding additional non-climatic elements that affect the growth, development, and distribution of FAW also needs more research.