The resourceful buff-tailed bumblebee

Everyone loves bumblebees. They are nice to look at, make a cute buzzing sound and almost never sting. But there is more to bumblebees than that.

published on: 8/2/2023

written by: Harriet Lambert

Bombus terrestris, the buff-tailed bumblebee, is a common sight in European landscapes. The abdomen tip is buff-colored only in queens, while it is white in males and workers. Image: Adobe Stock

Profile

Bombus terrestris, the buff-tailed bumblebee, belongs to the family of Apidae.
It is widely distributed in Europe.
It is used in greenhouse pollination, and it has established itself in many areas where it is not native, such as Japan, Chile, Argentina and Tasmania.
Its common name refers to the queen whose tail is buff-colored (brownish yellow). The abdomen tips of workers and males are white.
Buff-tailed bumblebees are, like most bumblebees, social animals. Their colonies consist of an egg-laying queen and a caste of workers which are sterile, limited to gathering food and caring for young.
Unlike honeybee colonies, bumblebee colonies usually last for just one season – or sometimes less.

Classification

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Apidae
Genus: Bombus
Species: B. terrestris

Important pollinator

Bumblebees pollinate a range of wild and crop plant species such as wildflowers, tomatoes, peppers, peas, apples, blueberries, melons and strawberries.

Challenges

Like other insects, bumblebees face great challenges. Many bumblebees have a long flight season (February/March – October/November), high energy demands, and a lifecycle with large variations in worker numbers through the year. This makes them particularly sensitive to seasonal fluctuations in floral resources that are becoming more frequent due to climate change. Also, they rely entirely on pollen and nectar resources within one kilometer of their nest. They are, therefore, strongly affected by changes in the local landscape.

Bumblebees in Switzerland

Bumblebees are declining across the world, posing a global conservation concern. Currently, there are approximately 250 bumblebee species worldwide. Switzerland has approximately 40 bumblebee species, four species have gone extinct: B. confusus, B. distinguendus, B. magnus, and B. pomorum.

Did you know?

A bumblebee is piercing a leaf. Image: © Harriet Lambert

When there is no food around, bumblebees aren’t entirely helpless. Our research group has discovered that, when there is a shortage of pollen, bumblebees take action: they pinch the leaves of plants that have not yet flowered. This damage stimulates the plants to produce flowers that bloom up to 30 days earlier than plants that have not been pinched. You can access the publication from here.

Bumblebee is damaging a plant — A bumblebee is damaging a plant. Image: © Hannier Pulido

Did you know?

Not all flowers are generous with their pollen. Bumblebees use a special technique to reach particularly well-hidden pollen. Find out more in our article "Buzz-pollination – Or why we need bumblebees in greenhouses."

Why is there no bumblebee honey in the shops?

Bumblebees do produce honey to feed their larvae. Unlike honeybees, however, they do not keep excess resources in their nest, but food is converted immediately into growing the colony. They also do not need to build up stores for the winter, since only the queen survives the winter. The rest of the colony perishes at the end of summer.

Life cycle of the bumblebee

Queen overwintering

The new bumblebee queens consume large quantities of pollen and nectar to build up fat reserves. Their hibernation lasts the entire winter. After hibernation, the queens of the common buff-tailed bumblebee (Bombus terrestris) appear in early February or March over several weeks (the timing of emergence differs between species). © Harriet Lambert

Queen foraging

The queen has to build a colony quickly, in order to maximize the number of workers helping her to produce the next generation of queens and drones. Particularly during the early stages of development many colonies perish due to a shortage of flowers in close proximity. © Harriet Lambert

Nest initiation

The queen lays her first eggs in a primitive ball made from pollen and wax and begins to forage for nectar and pollen to provision her developing larvae which emerge after approximately 4 days. © Harriet Lambert

Flower visitation, colony development

The queen continues to forage for nectar and pollen until the first batch of worker bees have developed (normally after 4–5 weeks) and are able to take over foraging duties. Workers are generally much smaller than the queen and are responsible for finding food and many of the ‘household’ duties of the nest, including tending to the new broods of larvae. © Harriet Lambert

Mating

The queen focuses now entirely on egg laying and the colony grows rapidly, reaching 300–400 individuals in some species. Later in the season, if the colony has reached a sufficient size, the queen transitions from worker production to the production of males and new queens, and the remaining workers begin to die off. The new queens mate, normally with only one male, and store the sperm until the following season. © Harriet Lambert