Osmia cornuta

Horned mason bee ( Osmia cornuta )

The Horned mason bee ( Osmia cornuta ) is a representative of the genre of mason bees. This occurs in South and Central Europe species is widespread in Germany, but in southern and central Germany far more frequently than in the north. The height level of 500 m it exceeds only sporadically. Like all mason bees she lives solitary and does not States.

Features

The Horned mason bee is one of the most striking wild bees of spring. While the bumblebee -like females (12-16 mm) of the body deep black and the abdomen are rust red furred, one can easily recognize the slightly smaller males in their white facial hair. Only the females have on the front head two small, hidden between the hair squirrel ( German name ).

Way of life

Food

Osmia cornuta is one of the wild bees, which can be observed already in the first warm days of spring (early to mid-March ) in the settlement area of ​​the people. Your food plants are here accordingly spring flowering bulbs such as the Siberian bluebell (Scilla siberica ). Both in their own supply of nectar and pollen in their choice of sources for the supply of the breed is the style but not picky. So far, representatives were known from a total of 13 plant families as pollen sources. Thus, it differs from many others, some highly specialized bee species. Light can be observed in parks and gardens, the females when collecting pollen on squill ( Scilla siberica ) or on Corydalis ( Corydalis ). Very popular are the flowers of willow ( Salix), maple (Acer), cherries and plums (Prunus ), apple (Malus ) and Pear (Pyrus ). Outside built nest these insects mostly in the south-facing, vegetation-free loess and mud walls of ravines and cliffs along river banks. The latter are likely to constitute the natural habitat.

Nesting

Their nests builds the preferred living in gardens and parks, wild bee in existing cavities of various kinds, eg in cracks in the walls, in holes in the plaster, in drainage tube of roller shutters and cracks in window frames, sometimes even in wells of bricks. Osmia cornuta takes very happy to artificial nest boxes. The nests themselves are usually line construction with up to 12 consecutive brood cells facing towards the exit towards a so-called " Empty" and a thick Verschlusspropfen are. Serves as a building material moist sand or clay that is mixed with glandular secretions.

Threats and conservation

Since the Horned mason bee nesting respect and food had no high demands, this Wildbienenart is not at risk in Germany. By appropriate nesting boxes and a rich range of appropriate spring flowering plants, the type to be easily promoted. It can easily be the Horned mason bee nesting boxes also attract if they are attached directly to the wall or other large areas. As artificial nesting opportunities wooden blocks are accepted with holes of at least 8-10 cm depth; even better is horizontally oriented bamboo pipes are of a length of 20-25 cm; the inner diameter should be 7-9 mm, respectively. An artificial nests and children can experience biology at close range. In this case, a possible fear of a stitch is unfounded. Mason bees are peaceful, even if hundreds of them nesting in a small space.

Literature (selection )

• Westrich, P. (1989 ): The wild bees in Baden-Württemberg. 2 volumes, 972 pages, 496 color photos; Stuttgart ( Verlag Eugen Ulmer). [ 1990 2, verb. Edition ].
• Westrich, P. ( 1997): Wild Bees at home and in the garden. - Worksheets for Nature Conservation, 22: 1-55; Karlsruhe.