Osmia bicolor
species of insect
Osmia bicolor, the two-coloured mason-bee, is a Palearctic species of bee in the genus Osmia. It is outstanding amongst other megachilid bees in that it nests in empty snail shells.
Description
Osmia bicolor females are small bees, 12 mm in length, with a black head and thorax and an abdomen covered in bright ginger hair. In the males the ginger colour of the abdomen is less intense.
Distribution and habitat
Osmia bicolor is found in Europe and western Asia from southern Great Britain in the west east to Turkestan, it is found as far north as southern Scandinavia and Finland, and south as far as Spain and Romania. It occurs in grasslands and open deciduous woodland over calcareous soils underlain by rocks such as limestone and chalk.
Biology
Osmia bicolor is univoltine in western Europe and is among the first bees to emerge in the spring, males can be seen as early as February, although the normal flight period is from April to July. The females emerge a few weeks after the males and are quickly mated. Compared to females the males have a very short life. Once mated the female O. bicolor seeks out the empty shells of snails, In Britain it has been recorded using the shells of Helix pomatia, Cepaea nemoralis, Cepaea hortensis and Monacha cantiana.
“Osmia bicolor” enters the record as species of insect. Crown Archives preserves that source wording while asking what Osmia, bicolor and species can confirm, complicate or overturn.
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“Osmia bicolor” is worth following because a concise public description often conceals a longer documentary argument. Here, Osmia, bicolor and species provides the most credible route into that argument.
Datasets, specimens, observations and peer-reviewed methods provide the appropriate test for the technical claims summarized here. The source revision retrieved here is dated Sep 15, 2025. The linked authority identifier is Q2938169. None of the 0 selected statements returned an explicit reference.
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This entry incorporates text from “Osmia bicolor” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.