Submitted to: Annals of the Entomological Society of America
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/6/2009
Publication Date: 9/20/2009
Citation: Carter, M.E., Smith, M.T., Harrison, R.G. 2009. Patterns of Genetic Variation among Populations of the Asian Longhorned Beetle in China and Korea. Annals of the Entomological Society of America. 102(5): 895-905 Interpretive Summary: The Asian Longhorned Beetle (ALB) is native to China and Korea, and has become a serious invasive insect species of urban forests in North America and Europe. Outside of China and Korea little is known about the life cycle of ALB, its attack and utilization of tree species and the species-specific predators and parasites which could be deployed in biological pest control programs. Key to developing this information is greater knowledge of ALB within its countries of origin. This study was conducted to identify ALB populations across their native geographic ranges in China and Korea and to determine how closely they are related. To conduct this study, genetic analysis was conducted on ALB collected across China and Korea. The data indicate that while beetles within a single population and among neighboring populations in China are somewhat related, previously isolated populations have undergone a substantial amount of mixing. Mixing of populations likely results from a combination of planting large areas with non-native tree species which are highly susceptible to attack by ALB, and from the movement of ALB within infested trees and wood across China. The end result has been the common occurrence of outbreak populations of ALB that continue to this day. When compared to the ALB populations in North America and Europe, these results will provide potential locations of ALB populations in China within which to search for species-specific natural enemies that will be among the most effective for biological control of ALB in North America and Europe.
Technical Abstract: Central to the study of invasive species is identifying source populations in their native ranges. Source populations of invasive species can provide important information about species life cycles, host use and species-specific predators and parasites which could be deployed in a pest control program. The Asian Longhorned Beetle (Anoplophora glabripennis Motschulsky) is a serious invasive pest of urban forests in North America and Europe. In this study we analyze mitochondrial DNA haplotype frequencies and microsatellite allele frequencies to characterize phylogeographical patterns in potential source populations of A. glabripennis. The data indicated that, while there is some significant affiliations of beetles within a single population and among neighboring populations in China, a substantial amount of genetic admixture has occurred. This genetic admixture is likely due to recent reforestation efforts in China where beetles from previously isolated populations moved into new areas of abundant, susceptible and stressed resources leading to outbreak populations. Therefore, it is possible that among population variation, found in historically separate populations of A. glabripennis in natural forests, was transformed into within population variation through recent admixture. Results suggest that the likely source populations for A. glabripennis in North America may be invasive populations themselves, with a high proportion of within population genetic variation. When coupled with similar genetic analysis of A. glabripennis populations in North America and Europe, the results will focus our search for natural enemies on those species that coevolved with the invasive populations of A. glabripennis in China. These results will also allow us to determine whether populations in North America and Europe have common or independent origins in Asia.