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通过mtDNA COI、COII和Cytb基因序列分析,对来自北美五倍子蚜(Melaphis rhois)3个种群32个个体和中国角倍蚜(Schlechtendalia chinensis)5个种群44个个体的种群遗传多样性和结构进行比较.三个基因联合序列数据集长为1522 bp,数据分析显示北美五倍子蚜基因的核苷酸变异较大,变异位点有165个(约10.6％),其中155个为简约信息位点,而来自中国的角倍蚜种群核苷酸变异位点仅25个,其中20个为简约信息位点,二者形成鲜明对比;来自北美的五倍子蚜种群所有个体共包括11个不同的单倍型,除了来自阿肯色州的一个个体和新泽西州的五个个体共享一个单倍型外,每个单倍型都由来自同一种群的个体共享;来自中国的角倍蚜种群共有13个不同的单倍型,其中3个为种群间共享单倍型,10个为种群独自单倍型.AMOVA(Analysis of molecular variance)分析表明北美五倍子蚜种群强烈的遗传分化(FST=0.7268),其中俄亥俄种群与其他种群之间的分化最大,来自中国的角倍蚜种群之间的分化程度(FST=0.2377)明显低于北美五倍子蚜种群.BAPS(Bayesian analysis of population struc-ture)、TCS(a statistical parsimony network)网络和系统发育树重建结果与AMOVA分析一致.北美五倍子蚜种群之间高度的遗传分化可能是由于北美五倍子蚜种群与其余东亚种之间的地理隔离导致的种群分化或有限的基因流而形成,而东亚种种群之间地理分布相对较近、中国传统中药五倍子的人工种植培育的影响以及偶然的通过水和/或风进行的蚜虫长距离传播等因素,使得中国角倍蚜表现出较低的遗传分化.俄亥俄州的五倍子蚜种群比较特殊,与其他种群间遗传分化较大,值得通过更多的野外工作、形态观察和扩大种群样本量来鉴定其分类地位.“,”We compared the population genetic diversity and structure of the Rhus gall aphids, Melaphis rhois from North America and Schlechtendalia chinensis from China, by analyzing a dataset of mitochondrial DNA comprising the genes COI, COII, and Cytb representing 32 individuals sampled across three populations of M. rhois and 44 individuals across five populations of S. chinensis. In total, the aligned dataset of mitochondrial sequences was 1522 bp in length. We found that Melaphis rhois showed considerable variation at 165 nucleotide sites (about 10. 6％) of which 155 were parsimony-informative. This is in contrast to S. chinensis, which had only 25 variable sites (about 1. 6％) including 20 that were parsimony-informative. Within M. rhois, there were 11 different haplotypes, each of which was found in only a single population except for one that was shared by one individual from Arkansas and five from New Jersey. Within S. chinensis, there were 13 haplotypes, three of which were shared among populations and ten of which were private haplotypes. M. rhois exhibited strong differentiation (FST=0. 7268) according to an AMOVA analysis with the greatest difference between a population from Ohio and all others. The differentiation among populations of S. chinensis was lower (FST=0. 2377). The AMOVA results were corroborated by an analysis with Bayesian analysis of population structure (BAPS), a sta-tistical parsimony network (TCS), and a reconstructed phylogenetic tree. The high degree of differentiation among populations of M. rhois may result from population subdivision or limited gene flow due to its geographic isolation in North America, separate from all other Rhus-gall aphids (12 of 13 species), which occur in eastern Asia. In contrast, S. chinensis may exhibit less differentia-tion due to the closer Euclidean distances between populations, anthropogenic effects from cultivation of the galls for traditional medicine, and occasional long distance dispersal of the aphids via water and/or wind. The population of M. rhois in Ohio is unique and genetically distant from other populations, thus it merits additional field work, morphological observations, and expanding the density of within-population sampling to test its taxonomic identity.