Bumblebee Activities

Bumblebee colonies have a yearly cycle, except for tropical species, where year-round colonies are known to survive for more than one year, due to the fact that there are year-round flowers available.

Mated queens hibernate, usually in the soil, in a place that can’t be warmed up too early in the year by the sun. This prevents premature emerging, with disastrous results when there are no flowers around yet. If the temperature falls below a certain point, the queen’s body automatically produces glycerol (anti-freeze).

In Spring she emerges, in dire need to replenish her stomach’s honey store, which she used up during the hibernation. After she has found a suitable nest, e.g. a deserted small rodent’s nest, she builds a wax honey pot and fills it with regurgitated nectar (honey). Not only she eats from her pollen store but turns it into ‘bee-bread’ ~ balls moistened with nectar. This way, even with bad weather the queen can survive a day or two.

Stimulated by the pollen the ovaries produce eggs, which she lays in batches of 4-16 on the ‘pollen-ball’ she then covers with wax. At this stage all the eggs are fertilized, for the queen needs female workers; queens are usually only produced at a later stage in the life of the colony. While the bumblebee queen broods the eggs like a bird, she replenishes her energy by drinking from the nearby honey pot. Through the bare patch on her abdomen she passes her body heat to the clump of wax-covered eggs. The larvae (who look like maggots) are eating machines.

Another batch of eggs is usually laid when the first batch is in the larval stage, and it takes 4-5 weeks to produce adult bumblebees. Depending on the species, of which there are about 250, worldwide, a colony can contain between 30 – 400 bumblebees.

When a female worker bumblebee emerges into the light for the first time, she memorizes the landmarks by making a zigzag flight, which enables her to recognize the nest entrance. She navigates by the sun and has an inbuilt clock to compensate for the rotation of the earth.
Most workers have foraging preference ~ particular species, shape or color of flowers.

It takes time before she learns how to get into the flowers to get her reward ~ the pollen. Monkshood e.g. is a ‘difficult’ flower, which can only be pollinated by bumblebees. Only they have the weight, strength and know-how to get inside.
Because it takes time to learn, each bumblebee usually specializes on one or two types of flower at the time, also depending on the availability. The first time a bee enters a flower, she has to take a leap of faith and the moment the top petal falls down behind her, she is locked in into the flower. In reaching for the nectary down at the bottom, she receives her reward, and with the pollen, rubbed on her body, she pollinates the next flowers she’s visiting. An experienced forager doesn’t hesitate to enter a flower: by using her weight she squeezes her way down, drinks the nectar and comes out rear first. Novice bumblebees turn around inside the flower and emerge head-first.

After each foraging trip, the worker performs a figure-of-eight dance on the combs in the nest to tell her workmates where to find good food.
After visiting a flower, the bumblebee leaves a scent mark, telling the other workers not to bother with that flower, thereby reducing their time probing unprofitable flowers.
With an average of 10 foraging trips bumblebees can provide the nest with 3 ml. honey a day. The collected pollen are stored in the pollen basket, used to feed the larvae. For a bumblebee, time is honey!

At night most workers return to the nest, unless they are surprised by a change in weather. Then they hide under or in a flower.
Only queens and female workers have stings, which is not barbed like a honeybee (which dies afterwards). She will only use it to defend the nest against intruders.

A bumblebee cannot fly if its wing-muscle temperature falls below 30◦C. Powered by the sugars from the flower’s nectar, in flight the muscle temperature stays between 30-44◦C.

Male bumblebee production means the beginning of the end of the nest. Males drink from the honey pot, but don’t do anything to replace it. Some males help inside the nest by incubating the young, but for the rest their sole purpose in life is to mate with a queen.

Once they leave the nest, male bumblebees spend the rest of their lives outside in the open, at night sheltered under flowers or inside of them.

A grounded bumblebee can be a lethargic male who needs his first nectar shot to wake and warm up. At the start of the summer, it may be a queen caught out in a sudden shower or a cold spell. She will revive as soon as she gets her nectar. However, when the bumblebee is found at the end of summer, it might be an old queen or worker, reaching the end of her short but very productive life ~ a worker lives only 4 weeks.

This is the way our Creator God made them:
A bumblebee queen emerges from hibernation, starts a colony, later helped by her female workers. In the course of summer unfertilized eggs (males) are laid and under the influence of hormones, the female worker larvae develop into new queens.

During the next phase, males and new queens mate, the colony disintegrates, all the old bumblebees die, while the new queen hibernates. And with the next spring, the whole cycle begins anew ~ creating a new generation of bumblebees, needed to pollinate flowers and crops.
What an awesome God we serve!

“Books are the bees which carry the quickening pollen from one to another mind.”
~ James Russell Lowell

Helpful website: www.bumblebee.org/