Schlüssel zur Trennung der Zwillingsarten Lasioglossum sexstrigatum (Schenck, 1870) und Lasioglossum sabulosum (Warncke, 1986) (Hym., Apidae)

Key to distinguish the sibling species Lasioglossum sexstrigatum (Schenck, 1870) and Lasioglossum sabulosum (Warncke, 1986) (Hym., Apidae). – Lasioglossum sabulosum was separated as a distinct species from Lasioglossum sexstrigatum by K. Warncke in 1986 but has not been recognised by subsequent authors. The validity of the species is supported by several new distinguishing characters. The female of L. sabulosum is characterised by long thorns on the inner spur of tibia 3, stronger punctuation of mesonotum and hypoepimeral area, and dense facial punctuation on chagreened ground. The male is distinguished by a wider temporal process, an apically strongly flattened reddish clypeus, by distinct punctuation of tergite 1, a flat base of tergite 2, and by longer pilosity on sternite 2. Differences in habitat preferences of the two species are described based on a big number of specimens. Records of L. sabulosum came from different kinds of dry and warm places, but not from loosely sandy grounds. L. sexstrigatum are just known from sandy areas. Both species are found all over Switzerland and Germany. In the south of Germany L. sabulosum is as common as its sibling species. In northern Germany L. sabulosum is much more rare than L. sexstrigatum.