Projecting the Potential Global Distribution of Sweetgum Inscriber, Acanthotomicus suncei (Coleoptera: Curculionidae: Scolytinae) Concerning the Host Liquidambar styraciflua Under Climate Change Scenarios.

Simple Summary: Acanthotomicus suncei is a newly discovered bark beetle in China that causes substantial mortality to American sweetgum Liquidambar styraciflua individuals. Currently, the number of host trees killed by this bark beetle is increasing. Climate change has exacerbated this problem, causing its range to expand. Considering the wide global distribution of its host, Liquidambar styraciflua, the pest is likely to continue to spread and expand. Here, using CLIMEX and the Random Forests model, we projected the potential global distribution of A. suncei concerning the host L. styraciflua. Under future change scenarios, the total suitable area is projected to decrease to a certain extent. However, the changes in its original habitats provide three spreading trends to Southwest, Central, and Northeast China. Meanwhile, suitable areas in some countries in Southeast and South Asia bordering China are also expected to show an increased distribution, which poses substantial challenges for forest managers. Our projected results provide significant data regarding the current and future potential distribution of A. suncei worldwide, which could be used as a reference for recognizing areas currently vulnerable to potential invasions by this pest. Acanthotomicus suncei is a newly discovered bark beetle in China that significantly threatens the American sweetgum Liquidambar styraciflua. In recent years, this pest has spread from its original habitat to many surrounding cities, causing substantial economic and ecological losses. Considering the wide global distribution of its host, Liquidambar styraciflua, this pest is likely to continue to spread and expand. Once the pest colonizes a new climatically suitable area, the consequences could be severe. Therefore, we employed the CLIMEX and Random Forests model to predict the potential suitable distribution of A. suncei globally. The results showed that A. suncei was mainly distributed in Southern China, in South Hokkaido in Japan, Southern USA, the La Plata Plain in South America, southeastern Australia, and the northern Mediterranean; these areas are located in subtropical monsoon, monsoonal humid climates, or Mediterranean climate zones. Seasonal rainfall, especially in winter, is a key environmental factor that affects the suitable distribution of A. suncei. Under future climates, the total suitable area of A. suncei is projected to decrease to a certain extent. However, changes in its original habitat require serious attention. We found that A. suncei exhibited a spreading trend in Southwest, Central, and Northeast China. Suitable areas in some countries in Southeast and South Asia bordering China are also expected to show an increased distribution. The outward spread of this pest via sea transportation cannot be ignored. Hence, quarantine efforts should be concentrated in high-suitability regions determined in this study to protect against the occurrence of hosts that may contain A. suncei, thereby avoiding its long-distance spread. Long-term sentinel surveillance and control measures should be carried out as soon as A. suncei is detected, especially in regions with high suitability. Thus, our findings establish a theoretical foundation for quarantine and control measures targeting A. suncei. [ABSTRACT FROM AUTHOR]