Predicting climate change impacts on potential worldwide distribution of fall armyworm based on CMIP6 projections

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is a highly destructive insect pest of several crop plants and threatening global food security. The current Coupled Model Intercomparison Project phase 6 (CMIP6) data set was analysed to predict the potential worldwide distribution of FAW under present and future climate change scenarios in 2050 and 2070 under Shared Socioeconomic Pathway (SSP) 1-2.6 and SSP5-8.5 emission scenario with 19 bioclimatic variables through maximum entropy (MaxEnt) niche modelling. The MaxEnt model predicted the potential distribution of S. frugiperda with area under the receiver operator curve (AUC) values of 0.915 and 0.910 during training and testing, respectively. Annual precipitation, annual mean temperature and isothermality were the strongest predictors of S. frugiperda distribution with 42.6%, 22.4% and 10% contributions, respectively. The recent CMIP6 models predicted higher suitability of FAW in North America, Africa and Asia under future climatic conditions. Global suitability of FAW is predicted to increase by 4.49% and 8.33% under SSP1-2.6 and SSP5-8.5 scenarios, respectively, compared to that of current climate conditions. Multimodel ensemble predicted the highest risk of invasion and spread of FAW by 2050 and 2070 under SSP5-8.5 scenario. The predictions could be used to forecast the potential spread of FAW and combating outbreaks well in advance. Our results will be an important guide for researchers, policymakers and governments to devise suitable management strategies against this highly invasive pest.