The taxonomy of Hylaeus Fabricius, 1793 has been relatively stable throughout time. Most of the species occurring in central Europe were described during the 19th century. However, species are still being described outside Europe (e.g., Dathe 2000), and sibling species are being differentiated from common species in central Europe (Dathe et al. 1996).
Hylaeus gibbus Saunders, 1850 is a well-known species that was described long ago. This species is related to the more common H. confusus Nylander, 1852, and the rarer, thermophilous H. pictus Smith, 1853. Various authors have published these species under many synonyms. Förster (1871), for example, described species that, based on general appearance, were related to the above mentioned ones, with most of them now synonymised. Dathe (1980) added the following species to the key of European Hylaeus: H. confusus, H. gibbus, and H. pictus. In this key H. pictus is mentioned as a well-recognised species, with uniquely shaped yellow marks on the mask and thorax. This species is distributed in “western and southern Europe, reaching Cyprus in the east”. The other two species probably occur throughout Europe. However, Noyes (2004) listed H. pictus as a synonym of H. gibbus. Schwarz et al. (1996) did not mention H. pictus or any of its synonyms in their catalogue of German, Austrian and Swiss bees because H. pictus has never been collected in Central Europe. This publication, prepared by the main authorities in Europe, contains almost all of the available names for Central European species of the gibbus-group and, thus, maintains H. pictus as a separate, valid species. Amiet et al. (1999) included H. confusus and H. gibbus as species common in Switzerland in their key for Hylaeus in the Fauna Helvetica series. They were unable to distinguish between H. gibbus and H. confusus reliably and presented a map of the distribution of both species together.
We present new taxonomic insight into the problem of differentiating between H. confusus and H. gibbus species. The identification of these species became more consistent after we distinguished four species in our material on the Hylaeus gibbus group from central and southern Europe. We differentiate between the following four species: H. confusus, H. pictus, H. gibbus and H. incongruus Förster, 1871. The last name mentioned has been recorded as a synonym of H. confusus (Schwarz et al. 1996, Amiet et al. 1999) and H. gibbus (Dathe 1980).
|Last Updated on Monday, 23 January 2012 13:44|