Honey bees are familiar to most but what about wild bees? In fact, it is the inconspicuous wild bees that have a high value for our nature.
Bee mortality has been on everyone is lips for years. But when it comes to bees, many people only think of the familiar honeybee – in contrast, you rarely hear about wild bees. Yet it is the native wild bee species that are often particularly threatened. There are many reasons for this, ranging from a decline in their habitat to insufficient food supply and the use of pesticides. But why are wild bees so important? And how to support the endangered wild bee species? We will tell you in today’s post.
- Identifying wild bees: which species are there?
- Wild bee life cycle
- Wild bee nests
- Do wild bees make honey?
- Can wild bees sting?
- Why are bees important in the garden?
- Supporting wild bees
Identifying wild bees: which species are there?
What kind of insect is this? You have probably asked yourself this question at some point. In fact, however, it is not that easy to identify wild bees: There are a lot of different species. Wild bees include all bee species of the superfamily Apoidea, except domesticated honeybees. Therefore, there are serious differences in appearance and size between individual bees. The smallest wild bee (the sand steppe bee) is only 4 mm in size, while the blue wood bee, the largest wild bee, reaches a stately 2.8 cm. How do I recognise wild bees then? Despite their great variability, you can basically tell by some points whether it is a bee or some other insect.
Detecting wild bees made easy:
- Bees have a three-part body.
- Their head has two clearly visible, long antennae.
- The two pairs of wings of the bees are centred to the back and attached to the middle segment of the body. They consist of transparent wing skin, which is interwoven with clearly visible veins.
- Bees often have a slight pubescence.
- Bees can be observed collecting pollen or nectar.
Wild bees and honey bees: Often it is not so easy to distinguish whether you have a wild bee or a honey bee in front of you. But if you look closely, you can discover two differences between classic honey bees and wild bees: The workers of honey bees typically have protruding hairs on their large compound eyes – in wild bees, this only occurs in cone bees. In addition, the honeybee lacks the spur on the rail of its hind legs, which is always present in native wild bee species.
Wild bee life cycle
As different as the various wild bee species look, their lifestyles are also different. In addition to the classic forager bees, which feed on nectar and pollen, there were also so-called cuckoo bees, which sneak into the nests of other bee species and kill the offspring there and eat the stores. Making general statements about the life cycle of wild bees is therefore not so easy. Nevertheless, we have compiled and answered the most frequently asked questions on the subject.
Where do wild bees live?
Wild bees belong to the most species-rich groups in the insect kingdom and are distributed almost worldwide. Germany is also home to numerous native wild bee species. The habitat of wild bees can look very different: In addition to richly structured forest edges, meadow orchards and grassland, some wild bees also use dry stone walls, quarry and steep edges or watercourse edges as habitats. Many native wild bee species are highly specialised in this regard, so they can only be found in habitats with special characteristics.
Tip: Wild bees particularly like to settle near a suitable food supply. Therefore, creating a wildflower meadow is a good first step to encourage these fascinating insects.
How do they live?
General statements about the way of life of wild bees are difficult to make because one actually distinguishes four different ways of life among wild bees. Solitary bees, also called hermit bees, build their nests without the help of conspecifics and also take care of their brood alone. Each nest therefore houses only one female, which alone takes care of the 4 – 30 brood cells. Social bees, on the other hand, are more reminiscent of the classic way of life of honey bees as many know it. Here the bees live together in communities and are in close relationship with each other. Depending on the wild bee species, these communities may have a few bees or several thousand individuals and may have a hierarchy of varying strictness. Midway between the solitary and social bees are the communal wild bees. Here, two or more females of the same generation often live together in a nest but care exclusively for their own brood cells. The last way of life has the cuckoo bees mentioned earlier – these nest in the nests of foreign bees and steal the supplies there.
How long do bees live?
Most of the native wild bee species in Germany are so-called univolent species. This means that there is only one generation per year. Often the adult bees live only about four to six weeks – this time they use for reproduction and the creation of brood cells with the necessary food supply for their offspring. The larvae of the wild bees then overwinter well protected in their nest, where they hatch as adults the next spring and reproduce again.
Wild bee nests
Wild bee nests are basically similar in structure to those of the honey bees we know: The basic element of every wild bee nest are the brood chambers, which are strictly separated from each other by partitions and serve as a place for the development of a bee from egg to adult. However, on further inspection of the nest of wild bees, one immediately notices that there are many differences here as well. Depending on the wild bee species, wild bee nests thus differ not only in size but also in architecture, choice of nest site, and materials used.
Where do wild bees nest in nature?
Native wild bee species are more or less specialised in their choice of nesting sites – this means that different wild bees only build their nests in places with species-specific characteristics. These nesting sites can look very different: Many wild bees build their nests in the ground, while other wild bees use tree trunks or plant stems. Nesting sites in cavities of stones or rocks and snail shells are also known. If there is no suitable site in the vicinity, some wild bee species will also accept a wild bee nesting site.
When do they nest?
Unlike honey bees, which reproduce almost throughout the warm season, wild bees often nest only once a year. Immediately after the wild bees hatch, the mating season begins, which is usually immediately followed by the brood business. When exactly this begins depends strongly on the wild bee species: roughly, wild bees are divided into spring, early summer, mid-summer and autumn species depending on their occurrence. However, the time of breeding can also be shifted forward or backward by several weeks due to weather conditions.
How do wild bees nest?
The way wild bees build their nests is strongly linked to the choice of nest site. Wild bee nests in the ground are often dug by bees themselves. Many bee species also gnaw their own tunnels into pithy stems and rotten wood. Other native wild bee species make life easier for themselves and use existing cavities in the soil, rocks or wood. Free-standing nests are particularly fascinating – these are often built by the bees themselves from resin or mineral or vegetable mortar in a suitable place.
How do wild bees build their nests?
Not only must the right nesting site be found but the nest must also be developed from the inside. Many wild bee species additionally line their brood cells from the inside with a secretion from their abdominal or salivary gland. Other bee species, on the other hand, use sand, clay or small stones as well as plant parts to build their nests from the inside. Plant mortar is also a popular raw material for building the cells inside the nest. Bumblebees, like the honeybee we know, have taken a special path: with their abdominal glands, they produce a special wax that is used for cell construction.
Do wild bees make honey?
On the subject of wild bees, the question is often asked whether wild bees also make honey. Often this question is answered with no but in fact this answer does not quite correspond to the truth: bumblebees, which also belong to the wild bees, do indeed produce honey – but in such small quantities that they are not useful for humans.
Can wild bees sting?
From a purely physical point of view, it is possible for most bee species to sting. However, the risk of being stung by wild bees is often much lower than that of honey bees. Solitary bees in particular are less willing to sting, as they are solely responsible for brood care – the sting and thus the loss of their own lives are thus only conceivable as a last resort for the bees. In contrast, bees that live in a large colony, like honeybees, sting more often because they often have a more aggressive nest defence.
Why are bees important in the garden?
Similar to honey bees, wild bees are also indispensable for biodiversity as they play the role of pollinators. In fact, wild bees are even more important in this role than honey bees: Due to their specialization on certain plant species, they are an important key to the conservation of many native plant species, as they have adapted precisely to them through evolutionary processes. But many crops are also pollinated by bees, including wild bees. This not only ensures the propagation of our crops but also has an impact on crop yield. And here, too, there are plants that can only be pollinated by wild bees: Did you know that tomatoes, for example, cannot be pollinated by honeybees, or only with difficulty? Since the pollen is very tightly held in the pollen sacs, they must be shaken out by vibration – this is best done by the bumblebee, which is one of the wild bees.
So by having wild bees in the garden, you can not only maintain diversity but also improve your own harvest. Moreover, in contrast to honey bees, wild bees fly much earlier and also in more adverse conditions: Honey bees only start flying at a temperature of 12 °C, and they also prefer to stay in their nests in rain and wind. Many wild bee species, on the other hand, fly much earlier; for example, the horned mason bee can be observed with temperatures as low as 4 °C. Especially in colder years, early bloomers are therefore mainly dependent on the pollination services of wild bees.
Supporting wild bees
The continuing sharp decline in numerous wild bee species worries many people; after all, wild bees are indispensable to our ecosystem. In particular, the decline of suitable habitats or the lack of suitable food plants ensure that the number of bees is constantly decreasing. Fortunately, garden owners can counteract this well: By making small changes in the garden, you can make it attractive as a habitat, attract wild bees and thus actively participate in wild bee conservation.
Create and maintain nesting opportunities
One problem many wild bee species face is that they can no longer find a suitable place to nest. It is particularly important here to preserve natural nesting opportunities: Dead wood, dry walls and pithy stems are great nesting sites for many bees and should therefore be preserved in the garden. Wild bees will also gratefully accept small, uncultivated horizontal areas with loess loam or drifting sand. Another good alternative is to create nesting aids for wild bees, for example sand lentils, deadwood piles or wild bee hotels in the garden. But beware – not every wild bee nesting aid offered on the market is actually suitable. Therefore, look carefully when buying.
Tip: Leave the stems of perennials in winter until the plants rip out in spring – these serve as nesting sites for many wild bees.
Create a food supply
Almost more important than a nesting aid are suitable food plants if you want to establish wild bees in your garden. Since most wild bees feed by gathering pollen and nectar, it is important to provide suitable food plants for wild bees. It is important to note that many wild bee species specialize in certain plant species, which is why native plants are the primary wild bee plants to consider. To appeal to as many different species as possible, it is therefore also worthwhile to provide a wide selection of forage plants for wild bees. Mixed flower seeds for wild bees are well suited for this: the different plants with different flowering times offer a particularly broad food spectrum.
Tip: Wild corners in the garden are a great way to create retreat and foraging opportunities for wild bees. The animals feel right at home among dead wood and native wild plants.
Stop using sprays
The fact that more and more wild bees are dying out is often associated with sprays. In fact, many chemical sprays not only kill pests but also negatively impact beneficial insects such as wild bees. Therefore, to protect wild bees, stay away from chemical sprays and fertilisers in the garden and instead use beneficial insect-friendly alternatives or organic pest control. Information on the harmfulness to beneficial insects can be found in the safety data sheet or the package insert of the respective crop protection product.