When most people think about bees, they think about sociable honeybees or large furry bumblebees.
But did you know that around 267 species of bees, that’s 90% of bee species in the UK are solitary, meaning they don’t produce honey, don’t have a queen to protect, they live alone and generally aren’t aggressive as they have nothing to protect.
These are called solitary bees.
What’s so special about solitary bees?
- Solitary bees vary considerably in size, appearance and where they choose to nest. Roughly 70% are called mining bees and nest in underground burrows. Bees that nest in houses are called cavity nesting bees.
- Do not live in colonies, produce honey or have a queen.
- Do not produce wax to construct the cells inside the nest, instead different species use different materials to construct their cells and nests.
- Drink nectar directly from the flower and spend most of their time collecting pollen which is mixed with a small amount of nectar as food for their young.
- Are fantastic pollinators: a single red mason bee is equivalent to 120 worker honeybees in the pollination it provides.
- Do not have pollen baskets for carrying pollen, meaning that each time they visit a flower they lose far more pollen than social bees, which makes them much better pollinators
- Provide each larva with everything it needs but they do not tend to the young as they grow and never get to see their offspring emerge.
- Are non-aggressive and do not swarm.
- Safe around children and pets.
Their place in the ecosystem
Solitary bees are easily overlooked but they are known to pollinate plants more efficiently than honeybees.
They provide an essential pollination service, pollinating our crops and ensuring those plant communities are healthy and productive. Without them mammals and birds would not have the seeds, berries or plants on which they depend: in fact, approximately one in three mouthfuls of food and drink require pollination.
Wildflowers provide essential resources of pollen and nectar for these busy workers – and ample nesting opportunities in their dry, hollow stems.
Some bees such as the harebell carpenter bee are so dependent on a particular wildflower plant (in this case bell flowers) they cannot survive without it.
How and when to identify solitary bees
Bees have four wings – whereas flies have two – and are generally hairier than wasps.
Solitary bees vary massively but you can identify which ones are nesting by the materials they use to close the tubes.
They usually live for a year but you’ll probably only see them during their active adult stage, over a few weeks in the spring or summer.
Different species do appear at different times: the red mason bee is the first to emerge, hence its importance in pollinating fruit trees, whereas leafcutter bees can be active as late as September.
What happens in the bee house?
Each female bee lays 20 to 30 eggs during her life.
When a bee finds a nest, she will collect materials to create the cell for her first egg: a ball of pollen stuck together with nectar for each larva to eat until it develops into an adult bee.
She places the ball inside the cell and lays an egg on top, leaving space for the larva to grow into an adult bee.
She builds a partition wall and repeats the process until the whole tube is filled, leaving a space at the entrance of the tube empty before closing it off and moving on to another tube.
Females choose whether to lay male or female eggs: since males emerge a couple of weeks before the females, she lays all the females at the back and males at the front.
Solitary bees spend their early months hidden in the nest growing.
They then spend the winter as a cocoon (or pupa) before emerging the following spring or early summer as adults.
What to look out for
You might notice bees buzzing around your house and on wet days during the flying season check inside the holes and might see them sheltering from the rain.
The only certain sign of nesting is seeing the ends of the tubes capped with either mud, leaves or fine hairs. The type of capping indicates the type of bee and it’s possible you might have more than one type at the same time.
The three bees that you are likely to find in your bee house are:
- They have red/gingery hair.
- Females have small horns on their heads.
- They use mud to cap tubes.
- They lay in March to July
The Leaf Cutter Bee.
- Has a broad head
- Large mandibles for cutting leaves
- An upturned abdomen.
- They use leaves to seal their home
- They lay in May to September.
The Wool Carder Bee.
- It has distinctive yellow and black markings on the flattened abdomen.
- It uses fine plant hairs to seal its home
- It lays its eggs from June to August
Photographs and information courtesy of
GoWild Botanic Gardens Kew https://www.growwilduk.com/wildflowers/bees-pollinators/take-crash-course-solitary-bees
Wildlife Trust – https://www.wildlifetrusts.org/blog/ryan-clark/guide-solitary-bees-britain.
Solitary Bee Quiz
- Do solitary bees make honey?
- Do solitary bees have a queen?
- You shouldn’t be scared of solitary bees. Why?
- Why are solitary bees so important to us?
- Can you name 3 solitary bees?
- Where do Mining Bees live?
- How many eggs does a female solitary bee lay?
- How does the Red Mason Bee seal up its eggs?
- What do the baby bees eat in their tube?
- Why does the Leaf Cutter Bee cut leaves?
All the answers are in the article above