【目的】 光肩星天牛Anoplophora glabripennis（Motschulsky）是国内最重要的林木蛀干害虫之一，在中国分布范围较广。近年来，形态学以及分子生物学的研究表明，光肩星天牛与黄斑星天牛A. nobilis （Ganglbauer）很可能是同一种的不同型。定量研究光肩星天牛两型的差异与表型多样性。【方法】 作者以光肩星天牛的20个地理种群的光肩星天牛分布区为研究对象，采用巢式方差分析和聚类分析对其头长、头后缘宽、前胸后缘宽等13个表型性状进行多样性分析。【结果】 表型特征在群体间与群体内均存在着广泛的变异，13个性状的平均表型分化系数为11.78%，群体内变异是其表型性状变异的主要来源；后翅长度与经度呈极显著负相关，与海拔极显著正相关以及与年降水量呈显著负相关。体长与鞘翅斑纹颜色与海拔高度分别呈显著正相关和负相关关系；在不同地理种群中，鞘翅斑纹颜色的分化系数达到最大，为50.53%；而以鞘翅斑纹颜色分类的两型差异显示各性状的表型分化系数均大幅度降低。【结论】 本研究首次将鞘翅斑纹的颜色进行数字化处理，并进行分类，结果显示各个颜色类群的分化系数均大幅度减小，说明颜色类群之间的分化要小于地理隔离所造成的差异，进一步验证了光肩星天牛与黄斑星天牛为同一种的不同型。

[Objectives]  To quantify phenotypic variation in the Asian long-horned beetle (ALB), Anoplophora glabripennis (Motschulsky), a widely distributed wood-borer in China, which morphological and molecular research indicates is probably synonymous with A. nobilis (Ganglbauer). [Methods] Phenotypic variation in 13 phenotypic traits in 20 natural ALB populations was studied and analyzed using ANOVA and hierarchical cluster analysis. [Results] There were significant differences in all 13 traits among populations and among individuals within populations. The main source of phenotypic variation was that within populations, the mean coefficient of phenotypic differentiation (V_st) was 11.78 %. Posterior wing length was negatively correlated with longitude, positively correlated with altitude, and negatively correlated with annual precipitation. V_st for elytra color between different geographic populations reached the maximum value of 50.53%. However, classification based on elytra color greatly reduced V_st between two types. [Conclusion] This study was the first to apply digital quantification of elytra color to coleopteran classification, an approach that drastically reduced the apparent coefficient of phenotypic variation between groups. This indicates that phenotypic differences between groups classified on the basis of elytra color are less than those caused by geographical isolation. Pending further validation, ALB and A. nobilis are probably different types of the same species.