The Harlequin ladybird Harmonia axyridis Pallas, native to eastern Asia, is an invasive, non-native species that has recently achieved an almost worldwide distribution. A conspicuous feature of this species is colour polymorphism of the elytra. In its native area, the populations consist of a recessive non-melanic morph, several dominant melanic morphs and small numbers of other (rare) morphs. The morph proportions in native populations have been intensively studied and vary with geographic area, climate and time. In contrast, colour polymorphism in invaded regions has been little studied. We examine and try to account for the morph frequencies observed across the different invaded regions. In America, monomorphic populations consist of the non-melanic morphs while European populations contain also melanic morphs. In particular geographic areas of Europe, the average percentage of the non-melanic morphs varied between 78 and 99%. It was highest in the lowlands of northern Italy and central and northern Europe and decreased in the Alps and western (Spain, UK) and eastern (southeast Russia) margins of the recently invaded area. In central Europe the frequency of the non-melanic morphs decreased over the course of the year but increased over the years from 2010 to 2018. The local differences might thus arise through gradual change of the morph composition of the founder invasive, non-native population. However, the variation in non-melanic morph frequency was not correlated with climatic characteristics that might affect coccinellid polymorphism. The observed rate of change in morph proportions in our data was too small to explain the diversification of what was supposedly a uniform invasive, non-native population at the point of introduction.

丑角瓢虫Harmonia axyridis帕拉斯（Pallas）原产于东亚，是一种侵入性非本地物种，最近已在全世界范围内分布。该物种的显着特征是鞘翅目的颜色多态性。在其本国地区，种群由隐性非黑色变种，几种主要黑色变种和少量其他（稀有）变种组成。本地人口中的变体比例已得到深入研究，并随地理区域，气候和时间而变化。相反，对侵入区域的颜色多态性的研究很少。我们检查并尝试解释在不同入侵区域观察到的变体频率。在美国，单态种群包括非黑色变种，而欧洲人群也包含黑色变种。特别是在欧洲的地理区域，非黑色素变体的平均百分比在78％至99％之间变化。它在意大利北部和中欧和北欧的低地上最高，在最近入侵地区的阿尔卑斯山和西部（西班牙，英国）和东部（俄罗斯东南部）边缘下降。在中欧，非黑色素变体的发生频率在一年中有所下降，但从2010年到2018年期间却有所增加。因此，本地创始性，非本地人的变体组成的逐渐变化可能会引起局部差异。但是，非黑色变种频率的变化与可能影响球虫多态性的气候特征无关。在我们的数据中观察到的形态比例变化率太小，无法解释所谓的统一侵入性，