MaxEnt and Biomod2 provide novel insights into the potential distribution dynamics of Spodoptera litura (Lepidoptera: Noctuidae)

Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) is a major invasive pest globally. Understanding its potential global distribution under current and future climate change is crucial for managing its spread. This study aims to predict its distribution dynamics and identify key influencing environmental factors. Currently, suitable habitats for S. litura exists on all 7 continents, with southern Asia being the most severely affected. Future projections under various climate scenarios, which indicates a general northward expansion and an increase in habitat suitability for this pest. The most critical environmental factor determining its distribution was the precipitation of the warmest quarter (bio18), with optimal suitability at 300 to 600 mm. This points to moisture availability during the peak growing season as a key mechanistic driver, potentially affecting larval survival, host plant quality, and phenological synchrony. The ensemble model from the Biomod2 package demonstrated higher predictive accuracy than a single model. Under the high-emission SSP585 scenario, suitable habitat is projected to expand by approximately 10.7 million km2 by the 2090s, with pronounced northward shifts in Asia and Europe. These projections, grounded in ecologically interpreted variable responses and uncertainty-quantified ensemble outputs, provide actionable insights for early warning and integrated pest management under climate change.