Mason Bees - Osmia rufa / O.cornuta

All-round Pollinator for Field & Greenhouse

A service of the Dr. Schubert Plant Breeding

Osmia rufa on Phacelia Copulation of Red Mason Bee Cocoons of Red Mason Bee Osmia rufa on Satureja hortensis Sambucus nigra as nesting material Sunflower Soil collector Borago officinalis Bee hotel Strawberryflowers Rapeseed

Details to Handle Red Mason Bees


Cocoons can be stored until use at ~4C (e.g. at the refrigerator) under dry conditions and without vibrancy.
Cocoons of the previous year can be stored until August/September.
Attention: Too long and incorrect storage can lead to increased mortality!


It is recommended to offer nesting and building material to achieve high pollination efficiency by supporting the natural effort of species preservation.
1. Nesting material:
Applicable are blocks of wood with channels, tubes or hollowed elder branches, which are open at both ends and have a calibre of 4 to 10mm.
The nesting material has to be positioned at a dry place.
2. Building material:
Moist loamy soil should be available. A small place of moistened, mixed soil is sufficient.


Application period:
March till September.
The eclosion of the bees takes from a few hours until ca.2 weeks depending on temperature, season and sex.
Within the first week the half of the bees eclose normally. (Longer storage for later application enables faster eclosion in a few hours.)

Application sites:
The cocoons have to be positioned near by nesting possibilities.
Enough food supply of pollen and nectar should be available.

Recommended application quantity:
For an area of 10m approx. 10-20 bees are recommended depending on plant distance and pollen supply.
Ca. 1 bee pair is sufficient for 1 fruit tree (i.e. ca. 600-1000 females/hectare. Female and male bees should be used in a well-balanced sex ratio of ca. 1:1.
Contact   Dr. Schubert Plant Breeding