''Osmia parietina'', also known as the Western mason bee or wall mason bee, is a species of

solitary bee Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfami ...

within the family Megachilidae.

Description

''Osmia parietina'' is mostly black in colour, however possesses ginger pubescence on top of the abdomen. They are a medium sized bee, which can be found in flight between the months of May and July.

Distribution and habitat

''Osmia parietina'' can be found across

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

, however is mostly restricted to upland, hilly and mountainous areas. It has been recorded throughout much of Northern Eurasia including the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...

and

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

. ''Osmia parietina'' is associated with areas of unimproved

grassland A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natur ...

, where their primary nectar source bird's foot trefoil ('' Lotus corniculatus'') grows. They also have a preference for upland herb rich

pastures Pasture (from the Latin ''pastus'', past participle of ''pascere'', "to feed") is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep, or swine ...

and woodland glades. Females build their nests inside the crevices of drystone walls, rock faces and standing deadwood.

Ecology

Although ''L. corniculatus'' is the primary

nectar Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists ...

source for ''Osmia parietina'', it has been recorded visiting flowers of other plant species such as: ''

Ajuga reptans ''Ajuga reptans'' is commonly known as bugle, blue bugle, bugleherb, bugleweed, carpetweed, carpet bugleweed, and common bugle, and traditionally but less commonly as St. Lawrence plant. It is an herbaceous flowering plant in the mint family Lamia ...

Hippocrepis comosa ''Hippocrepis comosa'', the horseshoe vetch, is a species of perennial flowering plant belonging to the genus '' Hippocrepis'' in the family Fabaceae. Description The overall appearance depends on its habitat: sometimes it forms upright clump ...

, Rubus fruticosus,

Sedum reflexum ''Petrosedum rupestre'', also known as reflexed stonecrop, Jenny's stonecrop, blue stonecrop, stone orpine, prick-madam and trip-madam, is a species of perennial succulent flowering plant in the family Crassulaceae, native to northern, central, ...

, Trifolium pratense'' and ''

Veronica chamaedrys ''Veronica chamaedrys'', the germander speedwell, bird's-eye speedwell, or cat's eyes, is a herbaceous perennial species of flowering plant in the plantain family Plantaginaceae. Description ''Veronica chamaedrys'' can grow to tall, but is fre ...

.'' The Western mason bee is also one of several host species for the parasitic Northern Osmia ruby-tailed wasp (''

Chrysura hirsuta ''Chrysura hirsuta'', also known as the Northern Osmia ruby-tailed wasp, is a species of parasitic cuckoo wasp within the family Chrysididae. Description ''Chrysura hirsuta'' can range in length from 7 - 11 mm long. The head and mesosoma of th ...

'').

Threats

The overgrazing of meadows where bird's-foot trefoil grow means that the plant cannot successfully flower, this harms the ''Osmia parietina'' population as bird's-foot trefoil is their primary source of nectar. Poor management of woodland habitats can also cause their population to decline. Sunny glades and woodland clearings are essential habitats for wildflowers, if these clearings are not maintained the wildflowers are eventually shaded out by shrubs and trees, which accelerates the decline of ''O. parietina''. The loss of sunny rock habitats for the bees to nest in due to shrub encroachment also threatens the species. Human activity such as the manual removal of drystone walls and standing deadwood also removes essential sites for nests to be built.

References

{{Taxonbar, from=Q2121537 parietina Insects described in 1828