中文摘要：

五倍子蚜共6属12种,除北美分布1属1种外,其余分布东亚。本研究采用数值分类和分子系统发育分析方法对北美五倍子蚜Melaphis rhois的形态特点和分类地位进行研究,以倍蚜6属8种179个有翅孤雌蚜为研究对象,对其头部、胸部、腹部的直接测量特征48个、量度间比例特征31个及转化为数值的描述特征29个共108个特征进行分析。基于欧氏距离的聚类结果显示,北美倍蚜M.rhois与倍蚜属关系较近,五倍子蚜8个种共形成3个大的聚类簇,北美倍蚜M.rhois与倍蚜属的倍蛋蚜Schlechtendalia peitan和角倍蚜S.chinensis聚为一支;铁倍蚜属的肚倍蚜蛋铁亚种Kaburagia rhusicola ovogallis和肚倍蚜枣铁亚种K.rhusicola ensigallis与小铁枣蚜属的红小铁枣蚜Meitanaphiselongallis、圆角倍蚜属的倍花蚜Nurudea shiraii和红倍花蚜N.yanoiella与铁倍花蚜属的铁倍花蚜Floraphis meitanensis分别聚为一支。另外,测定五倍子蚜8个种共16个样本的mtDNA COI基因序列（约1.2 kb）,最大简约法（maximumparsimony,MP）和最大似然法（maximum likelihood,ML）分子系统发育分析结果均显示北美倍蚜M.rhois与倍蚜属的关系密切,和形态数据得到的结果一致;但倍蚜8个种之间的聚类总体上与形态学研究结果不太一致,铁倍花蚜属的铁倍花蚜和小铁枣蚜属的红小铁枣蚜、铁倍蚜属的肚倍蚜枣铁亚种和肚倍蚜蛋铁亚种与圆角倍蚜属的倍花蚜和红倍花蚜分别聚为一支,彼此之间的关系尚需深入研究。

英文摘要：

Rhus gall aphids include six genera and 12 species,and are mainly distributed in East-Asia with only one species Melaphis rhois in North America.Based on morphological characteristics and molecular data,we studied the taxonomic status of the North America species M.rhois.The numerical taxonomy on eight species from six genera of Rhus gall aphids was studied using hierarchical clustering analysis.A total of 108 morphological characters from 179 individuals of the alate adults were evaluated from all parts of aphid body,among which 48 characters from head,thorax and abdomen were directly measured,31 characters were the ratio from two measured characters,and the rest were numerical values converted from morphological characters.The cladistic analysis based on the Euclidean distance showed that the eight Rhus gall aphid species are clustered into three clades,among which the North America species M.rhois is closely clustered with the two species from the genus Schlechtendalia;the two species from Nurudea and Floraphis meitanensis,Meitanaphis elongallis and two subspecies from the genus Kaburagia are clustered as a group,respectively.In addition,the 1.2 kb DNA sequences of mtDNA COI gene from 16 individuals of eight Rhus gall aphid species were obtained.Both of the MP and ML phylogenetic trees showed that the eight Rhus gall aphid species are clustered into three clades,and the North America species M.rhois clustered closely with the genus Schlechtendalia,which are consistent with the results of the morphological analysis.However,the relationship between the three clusters are inconsistent with that based on the morphological data.In molecular trees,North America species M.rhois and two species from the genus Schlechtendalia,F.meitanensis and M.elongallis,and two species from Nurudea and two subspecies from the genus Kaburagia are clustered as three groups I,II and III,respectively.The group I and II have relatively close relationship,but with very low bootstrap value（50%）.It is necessary to collect more species a