Habitat suitability for the soybean aphid, Aphis glycines, and its natural enemies: implications for biological control and soybean protection

The soybean aphid, Aphis glycines Matsumura, is one of the most destructive pests affecting soybean production, frequently inflicting substantial economic losses. In this study, an optimized MaxEnt model was employed to predict the habitat suitability of A. glycines , its host plant Glycine max , and four key natural enemies ( Harmonia axyridis , Chrysopa pallens , Episyrphus balteatus , and Lysiphlebia japonica ). Furthermore, the overlaying ranges of suitable habitats of A. glycines and these natural enemies were identified. Results indicated that the area under the receiver operating characteristic (AUC) values of the six models ranged from 0.856 to 0.981 and the true skill statistic (TSS) values from 0.470 to 0.733. The highest contributing variables for the models of A. glycines , G. max , H. axyridis , C. pallens , E. balteatus , and L. japonica were BIO04 (temperature seasonality), BIO18 (precipitation of warmest quarter), BIO14 (precipitation of driest month), BIO01 (annual mean temperature), BIO18, and BIO17 (precipitation of driest quarter), respectively. Different natural enemies exhibited distinct niche overlaps with A. glycines in spatial distribution. For instance, the overlaying range between A. glycines and H. axyridis were distributed across East China, Korea, and Japan, whereas those between A. glycines and L. japonica were mainly concentrated in parts of South China and most of Japan. The differences suggest that priority regions for the release of different enemies can be identified to potentially control A. glycines . Compared with previous modeling study on A. glycines , this study adopted a MaxEnt parameter optimization approach and defined the suitable habitats of A. glycines under the presence of its host G. max . The results could enhance the understanding of the potential distribution of A. glycines and effectively facilitate the selection and application of natural enemies for regional biological control of this pest.