The Bumble Bee Queen
Do Bumble Bees have a Queen?
The simple answer is ´Yes´. The Bumble bee queen plays a crucial role in the survival of her colony, as she is responsible for laying the eggs that will become the next generation of workers. Unlike honeybees, without a queen, the bumblebee colony will die because only the queen can produce females, so the colony cannot survive without her.
Contrary to their honey bee queen counterparts, bumblebee queens are not pampered and rule the colony. They have to fend for themselves.
Unlike the female bumblebee workers, a fertilized bumble bee queen can control the sex of her eggs by emitting a chemical signal (pheromone). This ability is not found in many other organisms. By actively controlling the sex of her offspring, she can optimize the genetic diversity of her offspring and increase their chances of survival. The role of pheromones in this process is complex and intriguing. Scientists continue to study this phenomenon to gain a deeper understanding of its underlying mechanisms.
Do Bumble bees sting?
Yes, Bumble bee queens (and workers) have a smooth stinger unlike honey bees, and can sting multiple times. However, they only sting when they feel threatened, they fight for a nest site, or their colony is under attack.
Size and Shape of Bumble bee Queens
Bumblebee queens are typically larger than worker bees, with a more robust and rounded body shape. They can range in size from 18-23mm in length, depending on the species. Additionally, their wings are longer and more pointed than those of worker bees, allowing them to fly faster and farther.
Coloration and Markings
Another key characteristic to look for when identifying a bumblebee queen is their coloration and markings. Bumblebee queens often have more vibrant and distinct coloration than worker bees, with brighter yellows, oranges, and reds. They may also have unique markings, such as a white or buff-colored band on their thorax. These coloration and marking differences can help you distinguish a queen from the rest of the colony.
Hairiness and Texture
Another important characteristic to look for when identifying a bumble bee queen is the hairiness and texture of their body. Queens tend to have longer and denser hair on their bodies compared to worker bees. This is because they need to keep themselves warm during the early stages of colony development. Additionally, the hair on their bodies may have a different texture, feeling softer and more velvety to the touch.
Behavior and Activity Level
Bumblebee queens also exhibit different behavior and activity levels compared to worker bees. Queens are typically larger and more active, flying longer distances and visiting more flowers in search of nectar and pollen. They may also be seen digging and creating nests in the ground or other protected areas. Observing these behaviors can help you identify a bumblebee queen and understand her role in the colony.
Nesting Habits and Location
Bumble bee colonies are smaller than those of honey bees. On average they range from as few as 50 individuals in a nest to 400, however, some species can reach colony sizes of up to 1700 individuals.
Bumble bee queens have specific nesting habits and locations that can help to identify them. They typically prefer to nest in underground burrows, such as abandoned rodent holes or under piles of leaves or grass. Some species also nest in other protected areas, such as under sheds or in compost piles. As their habitat is getting increasingly scarce, bumble bee queens also fight (until death!) to find a suitable nest site to rear her brood. Observing a bumblebee entering or exiting a potential nesting site can be a clue that you have spotted a queen.
The Life Cycle of a Bumble bee Queen
Bumble bee queens mate with drones during the first couple of weeks of their adult life. Depending on the species, mating can take place on the ground or close to it, or at tree-top height. Bumblebees typically mate during mid-afternoon, often around the same time each day. The queen can go on multiple mating flights and mate with several males, usually between 12-15. This increases the genetic diversity of the colony, and is important for the colony productivity and its resistance against disease.
Once the find a mate, they engage in courtship behavior. This involves the male fluttering his wings or even touching antennae and releasing pheromones to attract the new queen. When she accepts him, they will both form a “mating wheel”, where they mutually fly in circles while connecting their abdomens together as they mate.
Animals have adapted to harsh environments or climates through hibernation and diapause. Insects typically undergo diapause, whereas mammals undergo hibernation. During hibernation, mammals experience a significant lowering of body temperature to conserve energy. On the other hand, diapause does not have this characteristic. Both adaptations are crucial for survival during adverse weather conditions. Insects enter diapause to avoid starvation, predators, or unfavorable weather.
Bumblebee queens typically enter diapause during the winter months. They do so in underground burrows or other protected areas. As the weather warms up in the spring, the queen emerges from hibernation and begins her search for a suitable nesting site.
Searching for a Nesting Site
After emerging from hibernation, the bumblebee queen embarks on a crucial mission: finding the perfect spot to build her colony. She will often fly long distances in search of the perfect location, which may be a hole in the ground, a clump of grass, or even an abandoned bird nest.
This can be a challenging task, as the queen must balance factors such as shelter, protection from predators, and proximity to food sources. In addition, she may have to fight other queens for a suitable nesting site as these are becoming increasingly scarce due to the destruction of their habitat. These fights typically end in death for the loser.
She may fly long distances and explore multiple potential sites before settling on the ideal location. Once she has found a suitable spot, the queen will begin the process of building her colony and laying the foundation for a thriving bumble bee community.
Once the queen has established her colony, she begins to lay eggs. She constructs wax pots and fills them with nectar and pollen before laying her eggs on top. This phase is crucial for the queen as she requires a substantial amount of food to nourish not only herself but also her first batch of offspring. Similar to birds, bumble bee queens keep their brood warm by shivering her muscles to generate heat. When the larvae emerge, the queen forages to nourish her brood with nectar and pollen.
Haploid and Diploid Eggs
The bumblebee queen can lay fertilized and unfertilized egg. Fertilized eggs (Diploid) carry chromosomes from both sets of parents, i.e. the queen and males she mated with the previous year. These develop into either queens or workers. On the other hand, unfertilized eggs only contain chromosomes of the queen, and turn into male bumblebees. It is worth noting that bumblebee males are fatherless due to a biological phenomenon known as haplodiploidy. The queen can decide whether or not to fertilize the eggs with the stored sperm.
The queen of a bumblebee colony produces a unique pheromone that plays a crucial role in the development of the larvae. Within the first five days of their lives, larvae that are exposed to this pheromone will mature into workers. The larvae are fed and cared for by the queen and eventually develop into adult worker bees. The new adult workers then take on a variety of tasks within the colony. These include gathering food, caring for the new offspring, and defending the colony from predators. Relieved of her brood rearing tasks, the bumble bee queen can focus on laying more eggs.
Towards the end of the summer the queen stops to produce workers. She releases a pheromone within the colony that instructs workers to stop raising fertilized eggs as workers and starts to lay male eggs. Subsequently if the pheromone is missing, but the larvae receive a surplus of food during their final growing phase, they have the potential to develop into queens. As a result, queen larvae are noticeably larger than their worker counterparts. This caste determination process is thought to be similar across multiple bumblebee species.
As the colony grows, the queen’s role shifts from laying eggs to directing the activities of her workers and ensuring the continued success of the colony.
Bumble Bee Queen – Worker Conflict
Once the pheromone is no longer active the queen loses her dominance over the workers, and this may cause conflict between the queen and the workers. At the same times the queen begins to lay unfertilized eggs that produce male bees, the ovaries of some workers start to develop. Although it is possible for workers to lay unfertilized eggs that will turn into males without mating, they cannot produce queens or other workers.
Some workers, notably those performing household duties, attempt to lay their own eggs and may even feed on the eggs laid by the queen, including their sisters. This behavior results in conflicts between the workers and with the queen. However, some persistent workers successfully lay some eggs that reach maturity. On the other hand, the queen also tries to consume eggs laid by the workers, which are actually her grandsons. To maintain her dominance, she head-butts and bites her own daughters.
Caring for her Brood
As the sole reproductive member of the colony, the bumble bee queen has the important task of laying eggs and ensuring the survival of her offspring. But she doesn’t just lay eggs and leave them to fend for themselves. The queen also feeds and cares for her young, providing them with the nutrients they need to grow and develop. This includes regurgitating nectar and pollen for the larvae to eat, as well as grooming and cleaning them to keep them healthy. The queen’s dedication to her offspring is a key factor in the success of the colony.
The Bumble bee Queen’s Legacy: The Next Generation of Bumblebees
After a successful season of laying eggs and caring for her colony, the bumblebee queen’s legacy lives on through the next generation of bumblebees. As the weather begins to cool, the queen will produce a new generation of queens and males. These new queens will mate with the males and then hibernate for the winter, ready to start their own colonies in the spring. The cycle continues, with each new queen carrying on the genetic traits and behaviors of her mother, ensuring the survival and success of the bumblebee species.