Osmia cornuta

This Espèce present in all Europe (except in the Scandinavian Countries) is one of the many species of solitary bees (more than 35 species of osmies, only in France). It disappeared almost from the zones of intensive agriculture, but survives in urban areas, waste lands and zones of gardens in particular.
Elle car its name of the two horns related by the female to the clypeus (face). The male has a white pilosity characteristic to the level of the mandibles and its antennas are longer.
Taille: 12 to 15 mm,

Behavior:

This osmy is activated as of mid-March for average Europe, the males leaving a few days before the females. waiting close to the zones of nesting for a rapid coupling before this one do not leave to seek holes like site of nesting.

The eggs (4 to 6 mm each) are laid in row in a gallery chosen by the female in a hollow branch, a wall, etc after a long inspection and a complete cleaning of the hole. If the gallery is too long, a ground stopper is posed by the female to reduce the size of it.
L' osmy enters ahead the head its gallery. It régurgite of the nectar stored in its jabot, after which it arises, makes a half turn and D-between, this time at moves back in the nest to deposit there while being strongly made vibrate the horns the pollen fixed on its ventral brush. She repeats this horse-gear in each cabin which she closes of walls built to pass to the following one. She stops the gallery once her completed work.
Les larvae hatches 6 to 7 days after the laying. Those which result from first laid eggs (those of the bottom) are generally females which will develop more slowly (perhaps simply because of the lack of oxygen?), and will leave only after the males. The growth of the larvae lasts a few weeks. During approximately two months, the female builds such nests, the ones after the others.
At the end of the growth, the larva spins a cocoon of yellow-brown clearly and is transformed into nymph. the adult insect leaves its cocoon spring following to feed and reproduce in the months which follow.

Agronomic interest

This species appreciates the pollen of Rosacées, Crucifères, Salicacées and Papilionacées, butinant the day by temperatures of about 12 with 14°C, which makes of them the permiers pollinating of many fruit-lofts, this why they are appreciated fruit producers bio and others which go until raising them or to offer nesting boxes to measure to them.

Nesting box

A nesting box of superimposed grooved wood small planks (untreated) or tubes dependant units can be appropriate to them. The holes must make approximately 8 mms in diameters and be protected from the rain and the great colds. Tubes out of glass make it possible to see the larvae in the cabins of the nest.

See too

Osmia

External bonds

photographs of the larvae in growth
Example of nesting box for orchard (Gâtinais)

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