Bumblebees are social insects that are characterized by black and yellow body hairs, often in bands. However, some species have orange or red on their bodies, or may be entirely black. Their legs are also black. Another obvious characteristic is the soft nature of the hair, called pile that covers their entire body, making them appear and feel fuzzy.
There are many different kinds of bumblebees that you will see buzzing around gardens, fields and woods in search of nectar from flowering plants. They live in families called colonies. The queens survive a year and then die but the workers have a shorter and much busier life.
When the queen emerges from her hibernation shelter in the spring, she looks around for some food to give her energy, so her eggs can develop inside of her. She buzzes around close to the ground slowly, to and fro, searching for a good nest hole. She is looking for an old mouse hole or something similar to that, somewhere that has dry grass and moss inside.
Once the queen has found a nice warm and dry nest she hollows out a chamber inside and lines it with wax from glands on her abdomen. She then prepares wax pots to store food in and wax cells for her eggs. In fertilised queens the ovaries are activated when the queen lays her egg. Before she lays the egg, she will decide whether to use sperm from the spermatheca to fertilise it or not. Non-fertilised eggs grow into males, and only fertilised eggs grow into females and queens. She seals the cells with lids of wax. These eggs then hatch into larvae which need to be fed both nectar for carbohydrates and pollen for protein in order to develop. Bumblebees feed nectar to the larvae by chewing a small hole in the brood cell into which food is regurgitated. The larvae then feed on the pollen that they are fed within their cell and grow and moult four times. They then spin a silk cocoon and take about two weeks to hatch as bumblebees.
These then help their mother forage for pollen and nectar. After the emergence of the first or second group of workers, they take over the task of foraging so the queen can spend most of her time laying eggs and caring for the larvae. The cells are round and are attached to each other in a cluster. In the Summer a colony may contain 50 – 200 workers.
The workers are all female bees. Their job is keeping the queen and the developing young larvae supplied with nectar and pollen. They also help with building of the new cells and defend the nest against intruders. Towards the end of summer they raise young queens. The queen also lays a number of unfertilized eggs which grow into males which are called Drones. Drone bumblebees have no stings.
These leave the nest after maturation. Males in particular are forcibly driven out by the workers. Away from the colony, the new queens and males live off nectar and pollen and spend the night on flowers or in holes. The queens are eventually mated (often more than once) and then search for a suitable location for hibernating. These Queens are the only members left that will survive the winter and start the cycle all over again. The Drones once they have mated with a queen will then die. A nest will have died out by the first frost and are unlikely to be reused.
Bumblebees can be encouraged to nest by creating nest boxes for them. Make a nest box for wild bees.
Tips about bumblebees.
One common, yet incorrect, assumption is that the buzzing sound of bees is caused by the beating of their wings. The sound is actually the result of the bee vibrating its flight muscles, and this can be achieved while the muscles are decoupled from the wings—a feature known in bees but not other insects. This is especially pronounced in bumblebees, as they must warm up their bodies considerably to get airborne at low ambient temperatures. Bumblebees have been known to reach an internal thoracic temperature of 30 °C (86 °F) using this method. They can beat their wings up to 240 times per second.
Some bumblebees nest in tussock grass and some directly on the ground.
Bumblebees can reach ground speeds of up to 15 m/s (54 km/h).
Queen and worker bumblebees can sting but unlike a honey bee’s sting, a bumblebee’s stinger lacks barbs, so they can sting more than once. Bumblebee species are normally non-aggressive, but will sting in defense of their nest, or if harmed.
Bumblebees are important pollinators of both crops and wildflowers.
Bumblebees are in danger of dying out. In Britain, until relatively recently, 19 species of native true bumblebee were recognized along with six species of cuckoo bumblebees. Of these, three have become extinct, eight are in serious decline, and only six remain widespread. A decline in bumblebee numbers could cause large-scale sweeping changes to the countryside, leading to inadequate pollination of certain plants.