Using a combination of DNA barcodes and morphology, we examine species boundaries in bees of the genus Andrena subgenus Taeniandrena in Europe. First, we solve the long controversy surrounding the status of Andrena ovatula (Kirby, 1802) andA. albofasciataThomson, 1870, proposed to represent distinct species nearly 100 years ago, but mostly treated as conspecific in recent studies. Our results unambiguously support the presence of two taxa that are often found in sympatry: the first taxon, referred to asA. ovatula, is present in Northern Europe but also in Southern Europe along the Mediterranean coast; the second taxon is referred to as A. afzeliella (Kirby , 1802), stat. rev., with A. albofasciata considered to be a junior synonym (syn. nov.), and is widely distributed in Europe. Second, we show that another widely distributed species has hitherto been overlooked in Europe: A. ovata Schenck, 1853, stat. rev. Third, we demonstrate that two taxa currently treated as subspecies should be given specific rank due to significant morphological and genetic differences: A. croceiventris Morawitz, 1871, stat. rev., so f a r treated as a sub species of A. similis Smith, 1849, andA. vociferaWarncke, 1975, stat. nov., so far treated as a subspecies of A. gelriaevan der Vecht, 1927 . BothA. croceiventris andA. vociferahave particularly restricted ranges in Europe, being known only from central to southern Italy and Sicily , and continental France, respectively. Fourth, we describe a new species from Sardinia and Corsica, A. antonellae sp. nov. Lastly, the following new synonymies are proposed: A. similis, A. ocreata cyprisinaWarn c k e , 1975 and A. similis caraimica Osytshnjuk, 1994 are placed in synonymy with A. russula Lepeletier, 1841 (syn. nov.); A. fuscata (Kirby, 1802), A. canescens Schenck, 1853 and A. pseudovatula Alfken, 1926 are placed in synonymy with A. afzeliella (syn. nov.). Lectotypes are designated for A. afzeliella, A. fuscata (Kirby, 1802), A. ovata and A. wilkella (Kirby, 1802). Our results suggest a particularly fast diversification in this group of bees, leading to the presence of numerous species exhibiting particularly restricted geographic ranges. We discuss the implications for conservation of this astonishing cryptic diversity in European bees.
