Global climatic potential distribution of Spodoptera litura under current and future climates

Abstract

Spodoptera litura (Fabricius) is a highly polyphagous and migratory pest threatening global agriculture. Although currently concentrated in the Asia–Pacific region, its potential global climatic suitability under climate change remains poorly understood. We used the climatic niche model CLIMEX to estimate present and future global climatic suitability, calibrated with 30-year climate data centred on 1995, and projected under a high-emission (SSP5-8.5) scenario for 2050. The model reproduced the known distribution and identified climatically suitable areas beyond the currently known range, particularly in the Mediterranean basin and parts of the USA. Future projections indicate a poleward shift in potential distribution driven mainly by reduced cold stress. At the continental scale, Europe shows the largest relative increase in suitable area (approximately 83%), followed by North America (approximately 22%). In Europe, suitable areas expand along Mediterranean coastal regions and in parts of southern and western Europe. In North America, suitable areas for establishment extend across the US Gulf Coast and coastal California. Continental-scale changes in Asia are modest. However, in East Asia the northern establishment boundary shifts northward, extending across south-eastern China and reaching parts of the Pacific coast of mainland Japan. Suitability declines in some low-latitude regions, including parts of India, Pakistan, and northern Australia, where increasing heat stress exceeds the species’ optimal thermal range. Overall, climate warming is projected to expand climatic suitability for S. litura into higher latitudes, while reducing suitability in some already warm regions.