The Balkan Peninsula is one of the greatest hotspots for biodiversity in Europe. While the region has been investigated thoroughly, some parts remain understudied and may still harbour undiscovered diversity, even in well-studied organisms such as Lepidoptera. Here we investigated the group of the so-called anomalous blue butterflies, also known as ‘brown complex’ of the subgenus Agrodiaetus Hübner, 1822 including the taxa of the entire Polyommatus aroaniensis (Brown, 1976) species complex. This species complex is distributed in the southern part of the Balkan Peninsula and known to be represented by three closely related allopatric species, differentiated by their chromosome numbers (n) and mitochondrial (mt) DNA. These are P. aroaniensis sensu stricto (Southern Greece, Peloponnese, n=47–48; mt haplogroup aroa1), P. timfristos Lukhtanov, Vishnevskaya et Shapoval, 2016 (Central Greece, Attika, n=38, aroa2) and P. orphicus Kolev, 2005 (North-Eastern Greece, Southern Bulgaria, n=41–42, orph1). Based on an analysis of chromosomal, molecular and morphological markers, we demonstrate that a fourth taxon of this species complex exists in Albania. This taxon possesses the mt haplogroup aroa3, which is the most differentiated within the entire P. aroaniensis species complex, and the karyotype (n=42–43), which differs by one fixed chromosome fission from P. orphicus. The Albanian taxon seems to be ecologically specialised (habitat on dark-coloured, ophiolitic substrate soils) and differs in colouration (wing reflectance) from the others taxa of the P. aroaniensis species group. Based on the evidence here presented and following the current view of the taxonomy of the group, we propose considering the Albanian taxon as a new species, here described as Polyommatus luraesp. nov. At the contact zone between the new species and P. orphicus, in addition to typical ones, we detected specimens with haplogroup orph2, karyotype n=43 and intermediate morphology, which seem to represent P. lurae × P. orphicus hybrids.

中文翻译：

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综合分析揭示了与异常蓝调的阿尔巴尼亚种群内的栖息地分化有关的神秘物种形成（鳞翅目、灰蝶科、Polyommatus Latreille，1804）

 巴尔干半岛是欧洲最大的生物多样性热点之一。虽然该地区已经过彻底调查，但有些部分仍未得到充分研究，并且可能仍然存在未被发现的多样性，即使是在鳞翅目等研究充分的生物体中也是如此。在这里，我们调查了所谓的异常蓝蝴蝶群，也称为 Agrodiaetus Hübner 亚属的“棕色复合体”，1822 年包括整个 Polyommatus aroaniensis（布朗，1976 年）物种复合体的分类群。该物种复合体分布在巴尔干半岛南部，已知以三个密切相关的异域物种为代表，通过染色体数 (n) 和线粒体 (mt) DNA 进行区分。这些是 P. aroaniensis sensu stricto（希腊南部，伯罗奔尼撒半岛，n=47–48；mt haplogroup aroa1），P. timfristos Lukhtanov，Vishnevskaya et Shapoval，2016（希腊中部，Attika，n=38，aroa2）和 P. orphicus Kolev，2005（希腊东北部，保加利亚南部，n=41-42，orph1）。基于对染色体、分子和形态标记的分析，我们证明该物种复合体的第四个分类单元存在于阿尔巴尼亚。该分类群拥有 mt 单倍群 aroa3，它在整个 P. aroaniensis 物种复合体中分化最明显，以及核型 (n=42–43)，与 P. orphicus 的一个固定染色体裂变不同。阿尔巴尼亚分类群似乎是生态特化的（栖息在深色、蛇绿质基质土壤上），并且在颜色（翅膀反射率）上与 P. aroaniensis 物种群的其他分类群不同。根据此处提供的证据并遵循该组分类的当前观点，我们建议将阿尔巴尼亚分类单元视为一个新物种，此处描述为 Polyommatus luraesp。十一月 在新种与P. orphicus的接触带，除典型种外，我们还检测到单倍群orph2、核型n=43、形态介于中间形态的标本，似乎代表了P. lurae × P. orphicus的杂交种。