The Bumblebee Life Cycle

I was reading somewhere about a person using bumblebee’s for use in a greenhouse sense the hive is much,much smaller then a regular beehive. It sounds like a way to save a little time.

Here, we are going to take a look a the bumblebee life cycle.

Bee life cycles vary, depending on the species of the bee in question.  For example, honey bees live in large, complex colonies, with a queen that could live for a few years.  Bumblebee queens would rarely survive beyond a year.

If you’d like to know more about the life stages of the honey bee click here. Or see my general page about the commonc features of the life cycles for the different types of bees.

The Life Cycle Of The Bumblebee

Of course, whichever the species, every bee life cycle starts with an impregnated queen. In the case of bumblebees, the new young queens emerge from their nests at the end of summer or early autumn, mate, and then hibernate over the winter.

In order to prepare herself for leaving her cosy hibernation hole, the young queen bumblebee has to first do a little ’warm up’ – just as you or I may do our own little ‘warm up’ routine before going for a winter jog. To do this, she vibrates her flight muscles very fast to generate heat, and when ready, she’ll then take off to look for pollen and nectar.

Depending on the species, some of these queen bumblebees will appear in the spring the following year, from March onwards. However, some species may appear as early as February. This is sooner than honey bees and solitary bees.

This is a very vulnerable time for queen bumblebees. Pollen and nectar sources are scarce, and she’ll need to find both very quickly in order to sustain her during these crucial days. The nectar gives her energy whilst the pollen helps her to replace vital body fats. It also provides protein to help her ovaries mature, and is needed later to feed her brood.


Above: Bombus lapidarius queen feeding on Berberis

During this time, plants such as mahonia, pussy willow, crocuses, rosemary, winter heathers, blackthorn, pussy willow, berberis and daffodils provide a vital life line for bumblebees.

Once the queen bumblebee has recovered, her next task is to find a suitable place to nest.

An abandoned rodent hole, tussocky grass, or even a bird nest box can provide a suitable home, depending on the species.

Again, depending on the species, there are slight differences in the way broods are reared, however, a general description is as follows:

Once the nest site has been located, the queen bumblebee will build a little wax cup inside it, which she will fill with nectar to sustain her whilst she incubates her eggs. She’ll also create a further wax cell, in which she will deposit a mound of pollen, and then lay her eggs on top of it. She incubates the eggs by lying on top of them, and again, by vibrating her flight muscles to generate heat up 30 °C!

After about 4 days, the eggs hatch into larvae (these look a little like maggots).

The larvae continue to feed and develop, and will go through a number of stages in development (shedding their skin 3 times) until after about 14 days, they produce silken cocoons and pupate. Within the pupae, the larvae shed their skin once more, and undergo metamorphosis. After about 14 days, the little grub-like larvae are transformed into a young bumblebees, which bite their way out of their cocoons.

The first bees to emerge from these cocoons are young female worker bees. Meanwhile, the queen has already laid more eggs that are also in development. The newly emerged workers will be a great help to the queen in rearing the rest of the brood. Within a day or two, these workers will set about helping the queen, initially with nest duties, but some will then go out to forage for pollen and nectar for rearing the next brood (usually more workers). A colony of bumblebees could have between 50 – 500 workers, but will commonly consist of around 120 to 200.

At some point, the queen will stop producing workers, and will switch to rearing males and young queens. Once the males have emerged, they will soon leave the nest in search of mating opportunities.

Queens may remain in the nest for a while, laying down fat reserves in preparation for the winter hibernation.

All being well, a honey bee colony should survive the winter. This is not the case with bumblebees (although some species may continue foraging and pollinating winter plants until November). In the case of bumblebees, the young queens leave the nest, mate, then hibernate, and re-emerge the following year to establish new colonies of their own. And so the next generation of bumblebees begins.

It’s very important to note that fewer than half of all bumblebee colonies survive, so if you come across a bumblebee nest, please try not to disturb it, and spread the word about the need to help bees.

The nest will not be around for very long, and will provide an excellent pollination service in the neighbourhood. In addition, quite a number of bumblebee species are experiencing worrying declines, with some species endangered. You may even wish to consider providing artificial nest sites.