Global Dispersal Tendency Of Colorado Potato Beetle,Leptinotarsa Decemlineata(say)

Colorado potato beetle(CPB,Leptinotarsa decemlineata(Say))is a devastating invasive pest of potato both in its native North America and now across Eurasia.It also damages eggplant,tomato and feeds on several wild species in the Solanaceae,such as Solanum eleagnifolium and Solanum rostratum Dunal(SR).Since first categorized as a pest in 1864,CPB has spread rapidly across North America,Europe and central Asia.In light of its invasiveness and economic importance,it is necessary to study its global dispersal tendency in order to provide scientific support for CPB prevention and controL.The results of this study are as follows:1.We used mtDNA COI+ tRNA-Leu+ CO? sequences as genetic markers to analyze population genetic structure of 617 CPB individuals collected from 50 countries and regions.Our study suggests that the overall genetic structure of this beetle in main distribution areas was significant.There has no sign of isolation-by-distance.Populations of central and southern US plain areas(except Arizona),western and eastern US areas and Mexico have high genetic diversity.The Eurasia populations are more closely related to the populations from eastern United States.2.We used 670 distribution data of CPB and the global climate change data to model the global potential distribution of the beetle under current and future climate situation.Our study showed that under current climate situation,the highly suitable areas of CPB include southern North America,southern South America,most of Europe.With the change of global climate and environment,the geographical distribution of potato beetle showed a trend of northward expansion,and its distribution in the Americas and Asia increased significantly,especially in the highly suitable areas.3.In order to understand the wild host availability,we studied 1090 distribution data of SR and used the same methods to model the global potential distribution of the invasive weed under current and future climate situation.Our study showed that under current climate situation,the highly suitable areas of SR include southern North America,South America,Western Europe,and southern Oceania.With the change of global climate and environment,the geographical distribution of potato beetle showed a trend of northward expansion,and its distribution in the Americas and Asia increased significantly,especially in the highly suitable areas.The geographical distribution of SR also showed a trend of gradual northward expansion,and its distribution in the Americas,Europe and Asia increased significantly.The potential geographic distribution of SR and CPB was highly overlapped.4.During the global dispersal,CPB has a strong ability of population expansion,good host availability and a wide range of suitable habitat in the world.With the change of time and climate,it will continue to spread northward through natural and human assistance,and the global prevention and control situation is very grim.Therefore,on the basis of scientific research,it is necessary to establish the frontier biological safety system,strengthen international communication and cooperation,improve the early warning mechanism and take comprehensive measures to prevent and control it.