How to promote the presence of wild bees in our gardens?
For a population of a wild bee species to be sustainably maintained, the habitat must offer the following 3 elements:
Food resources, that is to say a sufficient and varied supply of flowers, meeting their need for nectar and pollen.
A specific nesting place: bare soil surfaces, plant species with hollow stems, …
Specific materials for nesting (soil, small pebbles, resin, plant hair), to make the partitions separating each laying cell (food reserve used for the development of a larva) and to block the entrance to the nest.
Photo : Eva Thibon
Let nature do its thing
Shifting mowing periods and leaving a few areas without mowing helps maintain a floral resource over the entire period of appearance of wild bees and wild pollinators in general.
For too rich soils, it is possible to evacuate mowed or mowed grasses which will impoverish the soil and find a greater diversity of flowers. A pasture, limited in time and rotating, can be considered.
It is also essential to remove plant protection products from the management of these green spaces.
Our wild bees and pollinators are not adapted to exotic flowers (California poppies, butterfly tree, …), which is why it is important to favor the local flora.
For this, some nurseries offer seedlings and seeds of local origin under the brand “Végétal local”. It is also possible to favor short circuits and / or alternative methods: cutting sampling, hay transfer or root ball division.
Here are some examples of species useful for feeding wild pollinators :
Liondent False dandelion
Below, here is a list of trees to favor :
Hawthorn to a style
Alisier of the woods
Alisier of the woods
The creation of an orchard or vegetable garden can also be a way to favor wild pollinators through the planting of species useful for feeding pollinators.
Habitat diversification is an essential link in the reception of wild pollinators. Like what:
– The creation of a water point,such as a pond. This allows, among other things, to maintain a floral resource even in case of drought.
– The implantation of hedgerow. It provides an abundant food resource as well as breeding habitats.
For terricolated bees
These species are quite undemanding. They can be found in lawns, under grass, or on trails continuously used by walkers, bicycles, ….
Possible developments: Pile of sandy earth, sand, or loose earth without pebbles, on a sunny area, against a wall or on the ground 20 to 30 cm deep.
Photo : Ville de Lille
For squatting bees
Some bees have a great ability to adapt and can settle in various types of natural or artificial crevices.
Possible developments: Construction of dry stone walls of traditional construction (without joints). These walls can be mounted in such a way as to create an aromatic spiral that will be a privileged place for wild bees.
Photo : 4d44 (wikimedia.fr)
For carpenter bees
These bees will come to dig their nests in the soft wood wormed or in the process of decomposition.
Possible developments: Maintenance of living trees but also of dead standing, felled or fallen trees as well as logs and branches on land.
Photo : Kai-Martin Knaak (wikimedia.fr)
For curular bees
These species do not dig their own nest but take advantage of stems already evided, such as those used in insect hotels (reeds, cane of Provence, …).
Several shrubs and shrubs provide a particularly important and abundant resource of hollow stems, the main ones are:
– The brambles / mulberry trees, real natural “bee hotels” and sources of delicacies for us.
Possible developments: Maintenance of suitable plants such as certain ronciers.
Photo : Agence GEMAP