In the past few weeks my eye’s occasionally been caught by an erratic and haphazard flight path around the plot; it’s a queen bumble bee emerging groggily out of her winter quarters and on the search for quick energy refuelling. Every flower is scrutinised and even the smallest blooms can accommodate this large body sucking up much needed nectar. There are twenty-four different species of bumblebee in the UK…that can be grouped according to tail colour: white/buff, red/orange and ginger/yellow. The life cycle of these pollinators is fascinating:
“Every nest starts with a single bumblebee queen. After emerging from her winter hibernation, she must quickly build up her strength by feeding on nectar from spring flowers. Then she searches for a dry, sheltered nest site. Common places include long tangled grass, compost heaps, bird boxes, and abandoned mouse and vole holes. Once the queen has chosen her new home, she gets cosy by burrowing into whatever nesting material is available to create a small round chamber. This material could be dry grass, old moss, or an old bird or rodent nest.
Inside the chamber, the queen produces wax flakes from her body and shapes them into a cup. She fills it with nectar collected from flowers, bringing it back to the nest in a special second stomach. She also collects pollen from flowers, packing it together into a tight clump and laying her first batch of eggs on top. Sometimes – especially later on in the colony – she will pack the pollen into a wax cup called a brood cell. The queen sits on the brood cell, shivering her flight muscles to generate enough heat to keep the eggs warm. She feeds from the little nectar pot when the weather is too bad to visit flowers.
After four to six days, the eggs hatch into white, C-shaped larvae. These wriggling offspring munch their way through the pollen that surrounds them. They grow very quickly and shed their skins several times. The queen now faces a tricky balancing act! She must keep the nest warm (a constant 25-32°C) by shivering, or her offspring will die. But she must also leave regularly to feed on flowers and bring back more pollen and nectar. Unfortunately, some nests and queens die at this point.
The former larvae dissolve into a soupy liquid before rebuilding themselves into adult bumblebees. The pupae are white and see-through at first, but as they develop, the colours and features of the adult bumblebees can be seen through the pupal skin. After two weeks, the new bumblebees force their way out of the pupae and then bite their way out of their cocoons. To start, they are weak, soft, and floppy! It takes a day for their bodies to harden and for their damp wings to dry, so they can fly. Their hair also starts out silvery-white before darkening to its normal colours. The queen’s first batches of eggs all hatch into female workers. This army of daughters takes over the important job of collecting pollen and nectar from flowers, to help feed new larvae and fill more wax pots with nectar.”
To find out more about these marvellous garden and allotment visitors go to Bumblebee Conservation Trust’s website, from which all this info has come. (The bumblebee life cycle. Bumblebee Conservation Trust. https://www.bumblebeeconservation.org)

Jenny Bourne
16.03.26