Earth bumblebee: interesting facts about the protected wild bee

the essentials in brief

• Earth bumblebees are bumblebees living in the ground, relatives of bees
• Like most insects, earth bumblebees are on the red list, so they are threatened with extinction
• Therefore, earth bumblebees in the garden should definitely be protected and not controlled under any circumstances

What are earth bumblebees?

Earth bumblebees belong to the genus of bumblebees (Latin: Bombus), which in turn are assigned to the real bees (Latin: Apidae). Like these, it is about state-building insects, which consist of a queen, the bumblebee colony, which is around 50 to 600 workers, depending on the species, and the male drones. There are 36 different species of bumblebee in Germany, 16 of which are already on the list of endangered species.

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• Build a nest for bumblebees in a flower pot

An estimated 250 different species are known worldwide, most of which are found in the climatically temperate regions of the northern hemisphere. Where it is warmer, the occurrences are limited to the cooler mountain areas. In addition to the state-forming species, there are so-called cuckoo bumblebees, which, however, are parasites. Like the bird that gives it their name, they lay their eggs in the nests of strange bumblebees and displace them.

species

The dark bumblebee (Latin: Bombus terrestris) is one of the most common and largest species of bumblebee. The generalist appears in almost all landscapes in Germany and is often seen in gardens. In addition, because of its great importance for pollination of plants, this species is bred and used in agriculture almost all over the world. However, there are also other species that are of great importance for garden culture and that we would therefore like to introduce to you at this point.

German name	Latin name of species	Occurrence	habitat	Characteristic features	Queen size	Size of workers
Dark bumblebee	Bombus terrestris	originally Europe, North Africa, Asia Minor	Forests, meadows, fields, gardens, both in the lowlands and in the mountains	black base color, two yellow cross bars, white abdomen	20 to 30 millimeters	9 to 10 millimeters
Big bumblebee	Bombus magnus	Central Europe	especially in the lowlands: heather, grassland, fallow land, meadows, embankments. Fields, gardens	black basic color, two yellow transverse bands, white abdomen, distinguishing feature: front band extends beyond the base of the wing	19 to 22 millimeters	11 to 17 millimeters
Light yellow bumblebee	Bombus lucorum	mainly Europe	open areas in the lowlands and in the mountains	black base color, first horizontal stripe light to lemon yellow, second horizontal stripe dark, white abdomen	18 to 21 millimeters	9 to 15 millimeters

In terms of their way of life and other properties, however, the bumblebees mentioned here are very similar.

Endangered bumblebees

Earth bumblebees and other bumblebee species are endangered for a variety of reasons. In addition to natural enemies such as hungry birds, hedgehogs or shrews, weather conditions and the availability of food available all year round also play a major role in population development. Industrial agriculture not only destroys valuable habitats for bumblebees and also ensures that bumblebees die out in the wild through the use of toxic sprays such as various insecticides.

Do not remove the bumblebee nest

It is all the more important to protect bumblebees in the garden and not to remove nests, for example. Do not be afraid of the animals: they will not harm you, but instead diligently visit your plants. In any case, the removal of bumblebees' nests is forbidden by law, as these species are highly threatened and protected. Only in absolutely exceptional cases - for example if the nest is in the house and you have been proven to be allergic - may specialists remove it.

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Discovered today while cleaning up old boards 😌🐝 I've never seen a bumblebee's nest so close. Of course, I carefully laid dad Brett over it again so as not to disturb the animals any further. Simply beautiful ❤ #hummel #erdhummel #nest #discovered #funddestages #nature # beautiful #kleinehelfer #garten # pollinate #important #nectar #futter #insects #ilovemygarden #picoftheday #instaday #stunning #happy

A post shared by Meike F. (@missfees) on Jul 23, 2019 at 3:51 am PDT

Can bumblebees sting?

Basically all bumblebee species are rather peaceful animals that rarely sting. In any case, only the female bumblebees have a corresponding piercing device, while the drones remain stingless. Unlike bees or wasps, earth bumblebees also threaten before they sting their supposed attacker. In doing so, they first lift one leg - which people often interpret as a “wave” - and finally hum at a conspicuous amount and turn onto their backs. The bumblebee stretches its abdomen ready to attack - and you should see to it that you get away quickly.

Even if you are not fast enough and are stung, it doesn't matter: bumblebees release less poison than bees when they sting, and their sting has no barbs and therefore does not get stuck in the skin. As a result, a bumblebee's sting is less painful than a bee's. The following symptoms are characteristic of a bumblebee sting:

• Reddening of the skin
• Swelling of the stitch point
• Formation of a white court
• First wound burns
• Itching doesn't start until later

Overall, the symptoms mentioned are less pronounced than with a bee or wasp sting and should subside after about a week.

Correct behavior

Do not be afraid if a bumblebee comes near you: the insect usually only confuses you with a flower, for example because you are wearing a sweet-smelling perfume or colored clothes. In this case, stay calm, move slowly and in no case do not hit the animal - the insect will quickly notice its mistake and keep flying. The peaceful bumblebees only sting when they feel threatened by, for example, hectic movements on their part.

Useful helpers in the garden

Don't be frightened if you spot a bumblebee nest in your garden - and don't try to remove it. The humming miracles of flight are extremely useful animals that are responsible for pollinating numerous garden plants such as tomatoes, cucumbers, zucchini and pumpkins. Bumblebees can pollinate many more flowers than bees, for example, because their proboscis are longer and therefore easier to get to.

In addition, it is thanks to their thick fur - in which the pollen get caught - that the pollen is distributed more evenly on the stigmas - and the fruits later grow more evenly and symmetrically. A nicely grown tomato or strawberry is usually the result of bumblebee pollination. Bumblebees are the first to fly in the year and are therefore indispensable for the pollination of early-blooming fruit trees - for example cherries, apricots or peaches.

Bumblebees also fly when it's cold

In contrast to honeybees and other bee species, bumblebees fly very early in the year - and even when it is still far too cold for other pollinating insects. The wintering queen of the dark bumblebee can be found outdoors at temperatures of around two degrees Celsius, while the honey bee only flies from around 12 to 15 degrees Celsius. This is made possible by the thick hair that reliably protects the “bees in fur” from the cold.

For this reason, some bumblebee species even occur at altitudes of up to 6000 meters and ensure the pollination of the alpine flora there - these are heights at which a honey bee does not even begin to dare to climb. In addition, bumblebees are incredibly hard-working: the lively fellows fly back and forth for up to 18 hours a day, covering many kilometers. They pollinate many thousands of flowers. Here, too, not only the earth bumblebees trump their close, honey-collecting relatives.

Digression

Bumblebees in agriculture

So it's no wonder that the dark bumblebee in particular is specially bred and used in agriculture. Whole colonies find a new habitat in various greenhouse crops, for example for strawberries or tomatoes, where they are used to pollinate fruit and vegetables - which we can then buy later in the supermarket. The following video shows exactly how this works:

Youtube

Appearance

The fat bumblebees have black hair and are easy to recognize by the two yellow bands. Depending on the species, these are colored differently. The dark bumblebee, for example, has dark yellow cross bars, the light yellow somewhat lighter. However, you have to look very carefully to notice the difference. The last two abdominal segments are in turn colored white in all species. Compared to other bumblebee species, earth bumblebees have slightly shorter proboscis, which for example in the case of the dark bumblebee are only about half the length of the body.

Incidentally, this species is the largest bumblebee species in Germany, the queens of which can be up to 30 millimeters long. The other bumblebees in the state only reach half this length and reach a maximum length of 17 millimeters.

Digression

This is why bumblebees can fly

For a long time, science racked its brains about why the fat bumblebees, which are rather heavy compared to other insects, can fly at all. After all, their wings are too short in relation to their large, heavy bodies - so how do the animals stay in the air? Scientists only came on the trail of the secret around 50 years ago: the extremely flexible wings of the bumblebee beat up to 200 times per second, creating vortices of air - which ultimately give the animal the necessary lift. Bumblebees are therefore not as sedate as they appear at first glance, but true flight artists.

Habitat and Distribution

Especially the dark and light yellow bumblebees are (still) quite common in Europe, where they prefer to live in open landscapes and light forests. The animals also like to nest in a bumblebee-friendly garden because they find plenty of food here - in the wild this is becoming increasingly difficult due to industrial agriculture, monocultures and the use of toxic insecticides.

The dark bumblebee builds particularly large nests, whose colonies can contain up to 600 individuals. As their name suggests, earth bumblebees like to build their nests underground and prefer to use abandoned mouse nests, but also other opportunities such as caves in appropriately built dry stone walls, stone piles or the like.

Life cycle

Earth bumblebees that are buzzing around at single-digit degrees from the end of February / beginning of March are always young queens from last year. These have wintered underground and are now looking for food - the supplies have long been used up. In addition, the animals need a lot of energy to build a nest and found a new bumblebee state, because unlike honey bees, only the queens overwinter. These were already mated by the drones in the previous year and begin to lay eggs after they have built their nests. From these first the workers hatch, later the drones and, at the very end, the new young queens. These in turn hibernate alone, while the old queen and her state die at the end of summer.

A bumblebee state emerges

Youtube

The young queens who wake up in late winter fly out as soon as the first rays of spring sun warm the ground. They look for food as well as potential nesting sites, which they especially in

• Mouse holes
• Stone columns
• Dry stone walls
• Pile of dead wood
• or special nesting boxes

find. If such an opportunity is found, the bumblebee brings material for nest building, for example grass, moss or leaves. She chops this up and, with the help of her saliva, forms a small hollow ball from it. In this the queen first creates wax cells filled with nectar or pollen, which serve as food. This is followed by the construction of the brood cells in which the first fertilized eggs are laid. Here the bumblebee is a real mother hen, because it warms and protects the clutch until the first larvae hatch.

These feed on the previously created food supplies, pupate and turn into finished workers within about three weeks. These now take on the search for food and brood care, because the queen is now only responsible for laying eggs. In this way, the bumblebee population grows very quickly to 400 to 600 animals, provided the weather is favorable.

Towards the end of summer, the male drones develop from unfertilized eggs, while new queens hatch thanks to a special diet from some fertilized eggs. These mate with the drones, fill their storage containers called honey bladders with food and go to their winter quarters. This is often found in tree roots, cracks in walls or in piles of leaves, where the animals finally lapse into cold rigidity. The rest of the Hummel people including the old queen, however, dies.

background

Dangers in winter

However, the dangers of winter are problematic and one of the reasons for the death of bumblebees. An estimated 80 percent of the young bumblebee queens do not survive the cold season, but fall victim to parasites or hungry animals such as hedgehogs, shrews or moles. It is all the more important that you as a gardener offer safe quarters for wintering.

Protect bumblebees in the garden

There are many ways to create a cozy living space for bumblebees in your own garden and thus contribute significantly to the protection of these animals, which are so important to us all.

Which plants should you grow?

The simplest method of bumblebee protection is to grow bumblebee-friendly plants. Basically, bumblebees are not particularly picky about their forage plants - but they still have favorite plants, which are usually characterized by a particularly high content of nectar and pollen. Make sure that your garden blooms all year round so that the hungry fellows can always find food. In contrast to bees, bumblebees do not store supplies and are therefore dependent on a table that is always well-laid.

An overview of suitable forage plants

Important early bloomers	Nectar-rich summer and long-term bloomers	Nectar-rich trees
Crocus, stemless cowslip, columbine, spotted lungwort, grape hyacinth, winterling, squill	Red and white clover, horn clover, adder's head, knapweed, cornflower, dandelion, mallow, gundermann, dost, tomatoes, strawberries, clematis	Black elder, dog rose and other wild roses, fruit trees, raspberries, hawthorn, eu cone, blackberry, currant, gooseberry

Ecological garden maintenance

In order for the bumblebees to feel comfortable in your garden, it should have a few options for building nests. To do this, simply install a bumblebee box, which is usually very popular, leave piles of stone and dead wood in suitable places and perhaps build a dry stone wall with long-blooming flowers with larger gaps between the stones. Much more important than suitable nesting options, however, is the management of the garden: Do not use chemical sprays, especially insecticides, pesticides and other poisons. These not only kill the bumblebees, but also numerous other useful garden dwellers.

Feed bumblebees

Just because of their size, bumblebees have enormous energy requirements. Especially shortly after hibernation, when the food reserves are used up and the bumblebee cannot find enough flowering plants, it is often too weak and threatens to die of hunger. A bumblebee crawling on the ground or other surface that moves slowly and does not fly away can be given a sugar solution to strengthen and save it.

And this is how you feed the earth bumblebee:

1. Mix half a teaspoon of sugar with a little water.
2. Use cold water.
3. Stir the mixture vigorously until the sugar is completely dissolved.
4. Scoop some sugar solution onto a teaspoon.
5. Hold this out to the bumblebee.
6. While doing this, stay calm and try not to shake.
7. Alternatively, draw up some sugar solution onto a syringe (without a needle).
8. Drip some of the solution right next to the weakened animal.

frequently asked Questions

Is it true that bumblebees shouldn't be fed?

Some experts take a critical view of feeding weakened bumblebees and argue that sick animals also reproduce as a result. Diseases and parasite infestation would spread and ultimately do more harm than good. The fact is, however, that earth bumblebees are an endangered and protected animal species - and by feeding you not only save a single bumblebee, but - especially in late winter / spring - an entire bumblebee state. In addition, the animals are not only weakened by diseases or parasites, but often simply due to a lack of suitable forage plants.

Are there also flowers that the earth bumblebee doesn't like to fly to?

In general, all types of flowers with double flowers are unsuitable for bumblebees and other insects as fodder plants. Many hybrid varieties have beautiful flowers, but no nectar or the earth bumblebee cannot reach them. It is therefore better to cultivate species with simple flowers. Silver linden and wisteria are also unsuitable for bumblebees. The problem with both species, however, is that they attract many of the animals - and these then practically starve to death in front of the table. Every year numerous dead bumblebees under the corresponding plants testify to this.

Can you build a bumblebee box yourself?

The variant with the upside down flower pot with the drain hole dug into the ground is very old and is often still touted in gardening magazines. Unfortunately, this method is completely unsuitable as a bumblebee nest because the flower pot does not offer any protection from rain - the moisture penetrates through the hole into the nest and practically molds it - and the bumblebees cannot crawl into it through an entrance on the side. The following solution, however, is much more elegant:

Youtube

Normal bumblebees nests, especially those above ground, for which NABU has published building instructions on its website, are not accepted by earth bumblebees.

Tips

You can also grow suitable forage plants for the bumblebee on the balcony and thus contribute effectively to bumblebee protection. In particular, summer flowers such as nasturtiums, stonecress, marigolds, everlasting flowers and cosmea, flowering herbs such as sage (e.g. white sage) and chives as well as balcony raspberries and balcony tomatoes attract many of the animals as well as other bees and butterflies.