Variation of suitable habitat distribution of Spodoptera frugiperda（J. E. Smith）in Yunnan based on BioMod2 combination model

【Objective】 Prediction of habitat distribution change of Spodoptera frugiperda（J. E. Smith）in Yunnan under the background of climate change，and it would provide scientific reference for agricultural departments to carry out the prevention and control of S. frugiperda and monitoring.【Method】 By systematically collecting the distribution points of S. frugiperda in Yunnan，combined with field survey data，then the BioMod2 combination model and ArcGIS 10.7 was used to simulate the potential distribution change of S. frugiperda under current and future climatic conditions.【Result】 The results showed that the 9 species distribution models were composed to obtain the mean values of AUC，TSS and Kappa of the combined model being 0.994，0.980 and 0.943 respectively，among which generalized linear model （GBM），generalized augmented model（GLM），random forest（RF），and artificial neural network（ANN）were the optimal models for predicting the habitat distribution of S. frugiperda. The worst performing model was surface distribution division room model（SRE），which failed the model accuracy test. The four most important environmental variables affecting S. frugiperda were slope，altitude，annual mean temperature and max temperature of warmest month. In the current period，the suitable area for S. frugiperda was 329400 km²，accounting for 83.61% of the total area of Yunnan. Under the conditions of future climate simulation，the suitable area had a relatively obvious expansion trend，especially the low and high suitable areas expanded greatly，with an average expansion of 27.84% and 12.80% respectively，while the unsuitable and medium suitable areas decreased，the mean declines were 19.69% and 32.92% respectively.【Conclusion】 Predictions based on future climate change show that the potential suitable areas for S. frugiperda in Yunnan has obviously expanded，and there is a trend of spreading to the high latitude and altitude areas.The results suggest that the climate change may result in the risk of continuous spread and harm increasing. In particular，close attention should be paid to the development of S. frugiperda situation in the severely affected areas and newly affected areas.