Objective This study aimed to clarify the current potential suitable areas of Bursaphelenchus xylophilus and to predict its future potential suitable areas in Yunnan Province of southwestern China under future climate scenarios, providing a theoretical basis for provincial authorities to establish early monitoring, warning and prevention and control measures for this disease.

Method Based on 56 geographic distribution points and 23 environmental variables of Bursaphelenchus xylophilus in Yunnan Province, the MaxEnt model optimized by ENMeval R package and ArcGIS Pro software were employed to predict its potential suitable area distribution under current and future climate scenarios.

Result The optimal parameter combination was feature combination FC = L + Q (linear + quadratic), with regularization multiplier RM = 1.5. The average AUC values for training and testing datasets were 0.891 3 and 0.861 2, respectively, indicating good model prediction performance suitable for assessing potential Bursaphelenchus xylophilus invasion risks. Slope, mean temperature of the driest quarter, soil type, and precipitation of driest quarter were dominant environmental variables influencing Bursaphelenchus xylophilus distribution. Under historical climate conditions, high-suitability areas were concentrated in Kunming, Qujing, Yuxi, Zhaotong, most of Wenshan, northern Honghe, and central Chuxiong, covering 7 169 km² (1.82% of Yunnan Province). Moderately suitable areas span 10 prefectures including Kunming and Qujing, covering 23 634 km² (6.00% of Yunnan Province). Under high greenhouse gas emission scenario, the suitable areas of Bursaphelenchus xylophilus showed a trend of expansion toward the southwest. Under the low greenhouse gas emission scenario, the suitable areas showed a trend of contraction toward the northwest and southern regions. The area of moderately suitable areas decreased under both scenarios.

Conclusion The optimized MaxEnt model accurately predicts the potential suitable areas of Bursaphelenchus xylophilus in Yunnan Province. The study indicates that temperature, precipitation and topography are the primary environmental factors influencing its distribution. Under future climate scenarios, the area of potential suitable areas of Bursaphelenchus xylophilus showed little fluctuation. Under a high greenhouse gas emission scenario, the suitable areas of Bursaphelenchus xylophilus exhibite a trend of expansion toward the southwest. Under a low greenhouse gas emission scenario, the suitable areas of Bursaphelenchus xylophilus show a more pronounced contraction in the northwest and southern regions, while the area of moderately suitable areas shows a decreasing trend under both scenarios. The overall expansion intensity under low greenhouse gas emission scenario is significantly lower than that under the high greenhouse gas emission scenario. This indicates that implementing proactive emission reduction measures to maintain the low greenhouse gas emission scenario can effectively suppress the significant expansion of the suitable areas of Bursaphelenchus xylophilus. This is of great significance for controlling its future damage range.