''Osmia uncinata'', the pinewood mason bee, is a species of solitary bee from the family Megachilidae It is an Arctic-alpine species which is found in the northern

Palearctic The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa. Th ...

, in 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 Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

it is a Biodiversity Action Plan priority species.

Description

''Osmia uncinata'' is a wasp like mason bee with a yellow and black striped thorax which is quite variable in its colour and the degree of hairiness shown. They measure between 7mm and 15mm in length.

Habitat

Great Britain Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

''Osmia uncinata'' is closely associated with relicts of the ancient

Caledonian Forest The Caledonian Forest is the ancient (old-growth) temperate forest of Scotland. The forest today is a reduced-extent version of the pre-human-settlement forest, existing in several dozen remnant areas. The Scots pines of the Caledonian Forest ...

, being found in woodland clearings, along paths through woodland, and on adjacent roadside verges where the principal forage plant, birds-foot trefoil ''

Lotus corniculatus ''Lotus corniculatus'' is a flowering plant in the pea family Fabaceae. Common names include common bird's-foot trefoil, eggs and bacon, birdsfoot deervetch, and just bird's-foot trefoil (a name also often applied to other ''Lotus'' spp.). It ha ...

'', is well established.

Distribution

In the United Kingdom ''Osmia uncinata'' is confined to the northern Scotland. In Europe its distribution covers northern Europe and the mountains of central Europe east into Asiatic

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

Biology

In Scotland the flight period is from late April or May to early July. This species has a single-brood in any season. It chooses preexisting cavities: insect burrows in dead wood or bark, especially those of the longhorn beetle '' Rhagium inquisitor'' and has used drilled borings in wooden blocks; between the thick bark of pine trees. The cell partitions and nest plug are made of leaf mastic. The nesting sites require full exposure to the sun. The eggs are laid in these small cells, which the female then seals with a reserve of food. The larva develops to a pupa and an adult while sealed in the cocoon, where it overwinters. The adults emerge in the spring to mate and to set up their own nests. On the continent ''Osmia uncinata'' is polylectic and has been recorded as utilising pollen sources from plants belonging to 10 different families. In Scotland, both males and females have been observed visiting ''Lotus corniculatus'', broom ''

Cytisus scoparius ''Cytisus scoparius'' ( syn. ''Sarothamnus scoparius''), the common broom or Scotch broom, is a deciduous leguminous shrub native to western and central Europe. In Great Britain and Ireland, the standard name is broom; this name is also used fo ...

'', bilberry ''

Vaccinium myrtillus ''Vaccinium myrtillus'' or European blueberry is a Holarctic realm, holarctic species of shrub with edible fruit of blue color, known by the common names bilberry, blaeberry, wimberry, and whortleberry. It is more precisely called common bilberr ...

'' and rowan ''

Sorbus aucuparia ''Sorbus aucuparia'', commonly called rowan (, also ) and mountain-ash, is a species of deciduous tree or shrub in the rose family. The tree has a slender trunk with smooth bark, a loose and roundish crown, and its leaves are pinnate in pairs o ...

'', but these latter three may be nectar sources for the adults only Meadows which border pine woods are possibly an important source of food by providing nectar to fuel the adults' flight and pollen to be provided for the larvae. The chrysidid 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 to 11 mm long. The head and mesosom ...

'' which is a known

parasitoid In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable str ...

of the closely related '' Osmia inermis'', may also be a parasitoid of ''Osmia uncinata'' as the wasp has been found in woodland sites where ''O. uncinata'' also occurs while ''O. inermis'' is not found in woodland.

Conservation

In Scotland it is Listed as vulnerable, the main threats to ''Osmia uncinata'' are the reduction of available habitat, the loss of the open areas within the forest and increased shading of the forage plants. Dead pine wood should be retained to provide nest sites, and the natural regeneration of the forest should be encouraged. As this species has a boreo-alpine distribution, the relict populations in Scotland are probably going to be negatively affected by

anthropogenic climate change Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...

. Measures taken to conserve other species found in Caledonian forest should benefit this species. Attempts to encourage them to use artificial nests in Scotland were unsuccessful but did find other rare species of arthropod such as '' Clubiona subsultans''. ''Osmia uncinata'' may be rare in Scotland due to a combination of the limited availability of the combination of old trees in sunny positions, beetle burrows (especially as ''Rhagium inquisitor'' is a scarce species in Scotland), and the availability of patches of bird's-foot trefoil.

References

{{Taxonbar, from=Q2414567 Hymenoptera of Europe uncinata Insects described in 1869 Taxobox binomials not recognized by IUCN