Large garden bumblebee facts for kids
Quick facts for kids Large garden bumblebee |
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| B. ruderatus on Centranthus ruber, Genova, Italy | |
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The Bombus ruderatus, also known as the large garden bumblebee or ruderal bumblebee, is a type of bumblebee with a long tongue. You can find these bees in Europe and parts of northern Africa. This bee is the biggest bumblebee in Britain. It uses its long face and tongue to reach nectar deep inside long, tube-shaped flowers.
Bumblebees are super important for helping many farm crops grow. Because of this, B. ruderatus and other bumblebees are sometimes raised by people and then brought to new countries, like New Zealand and Chile, to help with pollination. After being brought to Chile, B. ruderatus has also spread into Argentina. Sadly, the number of these bees has been going down. Because of this, they are now part of a special plan called the Biodiversity Action Plan to help protect them.
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What is a Large Garden Bumblebee?
Bombus ruderatus belongs to the insect group called Hymenoptera, which includes bees, wasps, and ants. It is part of the Apidae family, which are the bees. This specific bee is in the genus Bombus, which is the group for all bumblebees. There are 239 different kinds of bumblebees in the world, and 23 of them live in Britain.
B. ruderatus is closely related to another bumblebee called Bombus hortorum. Both of these bees are part of a smaller group called Megabombus.
How to Identify a Large Garden Bumblebee
Queen B. ruderatus bees are about 22 mm long. Worker bees are about 16 mm long, and males are about 15 mm long. This bee has a long face and a long tongue. These features are perfect for drinking nectar from flowers that have long, narrow tubes.
The main color of its body is black. It has two yellow bands on its upper body (called the thorax). One band is near its head, and the other is closer to its wings. There is also a thin yellow band on its belly (called the abdomen). A black band sits between its wings, separating the two yellow bands on its thorax.
It can be tricky to find queens because these bees are not very common in many places. Also, there are fewer queens in a bee colony compared to workers.
Telling B. ruderatus and B. hortorum Apart
It's often hard to tell B. ruderatus and B. hortorum apart because they look very similar. Some scientists have even wondered if they are actually the same species! Both bees are about the same size and are black with two yellow bands. The male bees also have similar body parts.
However, there are small differences you can look for. For example, the two yellow bands on B. ruderatus are usually about the same width. But on B. hortorum, the band closer to the wings is often narrower than the one near the head.
Even with these small differences, it can still be hard because bees within the same species can look a little different too. Scientists have studied their DNA to be sure. They found enough differences in their DNA to confirm that B. ruderatus and B. hortorum are indeed two separate species.
Where Do Large Garden Bumblebees Build Nests?
Most Bombus ruderatus nests are built underground. Queen bees sometimes go back to where they were born to start their own nest. However, they will check the spot carefully to make sure it's a good place to build a new home for their colony.
Where Do Large Garden Bumblebees Live?
Bombus ruderatus naturally lives in Europe and northern Africa. They prefer large, open areas like meadows that have lots of flowers. These flowers must have long, tube-shaped petals to provide food. It's very important that there are plenty of pollen and nectar sources close to their nests from April to September.
In Europe, you can find these bees in countries like Austria, Belgium, Britain, France, Germany, Italy, Poland, Spain, and Switzerland.
How They Spread to New Countries
Since the 1800s, people have used B. ruderatus in other countries to help pollinate crops. In 1885, they were brought to New Zealand to pollinate a plant called red clover. Then, in 1982, they were introduced to Chile for the same reason. Since 1993, these bees have also been seen in Argentina's Patagonia region. Scientists think they traveled there through the low parts of the Andes mountains.
Why Bumblebee Numbers Are Declining
Many parts of the world, including western Europe and North America, have seen fewer native bumblebees. This is due to many reasons. In Britain, for example, the breaking up of their natural homes (called habitat fragmentation) has caused the number of B. ruderatus bees to drop. This has also made it harder for them to pollinate as widely as before.
B. ruderatus often lives in the same areas as B. hortorum. However, B. hortorum seems to be less affected by habitat changes and is still quite common in Britain. Sadly, B. ruderatus has become one of the rarest of the 23 bumblebee species in England.
Life in the Colony
In New Zealand, colonies started by natural Bombus ruderatus queens often had more male bees than female bees. Also, the males usually came out of their cocoons before the new queens. Having more males can happen when a queen mates with several different male bees.
What Happens to Young Bees?
Sometimes, worker bees lay eggs, and the queen bee might even eat these eggs. Workers and sometimes queens also pull live young bees (called larvae) out of their cells and leave them outside the nest. Scientists have looked at these ejected larvae and the ones that survived, and they couldn't find any physical differences. So, the exact reason why they are ejected is still a mystery. However, female larvae were removed more often than male larvae.
What Do Large Garden Bumblebees Eat?
In Argentina, Bombus ruderatus bees mostly feed on plants from the Fabaceae (pea family), Alstroemeriaceae (lily family), and Rosaceae (rose family). When new queens first come out, they tend to eat more pollen than the smaller male bees.
What About Parasites?
A tiny parasite called Apicystis bombi has recently been found in Bombus ruderatus bees in Argentina. This parasite can cause many problems for bee populations. It is very harmful, can infect many different bumblebee species, and affects both bees raised by people and those born in the wild.
Apicystis bombi can cause serious physical and behavior problems in bee colonies. It can also stop new colonies from forming, which increases the number of bees that die. Scientists think B. ruderatus caught this parasite from another bee species that was brought to Argentina, called Bombus terrestris. Before B. terrestris was introduced in 2006, Apicystis bombi had not been found in any bees in Argentina.
Parasites can spread through something called "pathogen spillover." This happens when new species brought into an area pass diseases or parasites to the native species. This is thought to be a reason why bumblebee populations are decreasing.
Why Are These Bees Important to Humans?
Helping Farmers and Crops
Bumblebees are very important pollinators for many crops and flowers. Some of these plants are vital for farming and the economy. Bumblebees are often better at pollinating than honeybees because they can fly and work even when it's colder. Honeybee pollination tends to slow down as the weather gets cooler, but bumblebee pollination usually stays steady.
In 1982, Bombus ruderatus was brought to Chile to pollinate red clover. Red clover is a small plant grown for its seeds. Chile exports a lot of red clover seeds, so how well their bees pollinate directly affects their farming and economy. Most red clover pollination is done by honeybees, but their activity decreases in late summer and early fall, leading to fewer seeds. B. ruderatus was introduced to help make up for this drop in pollination during the later season. While there have been good farming benefits from more seeds, there have also been negative effects, like fewer native bee populations.
How New Bees Affect Native Bees
When new species are brought into an area (they become invasive species), they can sometimes harm the native species. They might compete for food and resources, or they might spread illnesses. For example, when Bombus ruderatus and Bombus terrestris were introduced in Argentina, they caused the native bee species, Bombus dahlbomii, to decline.
Scientists saw that after B. ruderatus was introduced, Bombus dahlbomii visited certain plants less often, while B. ruderatus visited them more. A big reason for the decline of Bombus dahlbomii in South America might be the Apicystis bombi parasite brought by B. terrestris. But competing for food and foraging areas with B. ruderatus has also made the decline of Bombus dahlbomii worse. Generally, B. dahlbomii does better in areas where B. ruderatus or B. terrestris have not yet arrived.
Why Bee Populations Are Declining
In recent years, many countries have seen fewer bees, especially bumblebees. Some possible reasons include their homes being broken up (habitat fragmentation), climate change, disease, farm chemicals (like agrochemicals), and other factors. As mentioned, B. ruderatus numbers have dropped in Britain, and they have completely disappeared from many places where they used to live. When bee populations decline, it can lead to other problems in nature, such as fewer plants growing that depend on bees for pollination.
Helping Bees Recover
Recently, the European Union has started plans to help bees. These plans pay farmers to manage their land in ways that benefit bee species. Britain has a similar plan called the Environmental Stewardship scheme. Its goal is to provide more pollen and nectar for bumblebees.
These plans hope to fix some of the problems caused by modern farming. For example, intense farming with less mixed crops has made habitats simpler. This might have led to fewer bumblebee populations by reducing the quality and amount of food and homes available to them.
Images for kids
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B. ruderatus on Hibiscus syriacus
See also
In Spanish: Bombus ruderatus para niños
