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 ofAndrena 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 asA. afzeliella(Kirby, 1802),stat. rev., withA. albofasciataconsidered 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. ovataSchenck, 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. croceiventrisMorawitz, 1871,stat. rev., so far treated as a subspecies ofA. similisSmith, 1849, andA. vociferaWarncke, 1975,stat. nov., so far treated as a subspecies ofA. gelriaevan der Vecht, 1927. BothA. croceiventrisandA. 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. antonellaesp. nov.Lastly, the following new synonymies are proposed:A. similis,A. ocreata cyprisinaWarncke, 1975 andA. similis caraimicaOsytshnjuk, 1994 are placed in synonymy withA. russulaLepeletier, 1841 (syn. nov.);A. fuscata(Kirby, 1802),A. canescensSchenck, 1853 andA. pseudovatulaAlfken, 1926 are placed in synonymy withA. afzeliella(syn. nov.). Lectotypes are designated forA. afzeliella,A. fuscata(Kirby, 1802),A. ovataandA. 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.
