A Guide to UK Solitary Bees

So, you have heard of bumblebees and honey bees, yes? But, did you know that there are such beings as solitary bees? No? Don’t worry, we have the ultimate guide to everything you need to know about solitary bees in the UK, right here.

What Are Solitary Bees?

You may have seen small, fluffy bees buzzing around your garden or local park at some stage and you possibly categorised them as a honey bee, right? Or, perhaps you didn’t think much of it. Well, either way, these are most likely solitary bees!

Across the globe there are approximately 20,000 known bee species, with only 250 of these being bumblebees, a mere 9 being honey bees and a few social bees. Therefore, most bees you see are actually solitary bees.

In the United Kingdom, we have about 270 varying types of bee species — a whopping 250 of which a species of solitary bee! They are brilliant pollinators and it may not be such a surprise to learn that they do not nest in colonies like the well-known honey bees and bumblebees. But, you’ll have to read on to find out the nest sites of solitary bees!

How to Identify Solitary Bees in the UK.

With the right knowledge and tools, you can easily identify solitary bees in your area and learn more about their unique behaviours and habits.

Solitary bees nest individually inside small holes in wood or soil, or even inside plant stems. Solitary bees typically range in colour from light brown to black, though some may be more brightly coloured.

There are a number of tools and techniques that you can use to help you identify solitary bees in your area. One of the most useful is a simple identification guide, which typically contains information on a variety of different species as well as tips for spotting wild bees.

If you are interested in learning more about solitary bees, there are many books available to buy online that can help you gain a deeper understanding of these incredible creatures. Such as ‘The Solitary Bees: Biology, Evolution, Conservation’ by Bryan N. Danforth, offering an unparalleled look at these remarkable insects. By taking some time to learn more about the many solitary bees, you will be better equipped to identify them and appreciate their important role in supporting a healthy ecosystem.

As a rule, a solitary bee is usually fluffier than wasps which is a handy fact to know when identifying what is buzzing around your picnic table! 

Types of Solitary Bees

Some common types of solitary bees include Mason, Mining, Carpenter and Leafcutter Bees.

Mason Bees get their name from their habit of building nests out of mud or clay. These remarkable little insects are some of the most interesting and important pollinators around.

Mining Bees, also referred to as digger bees are well-named, as they spend much of their time burrowing tunnels in the ground to create their nests.

Carpenter Bees are so named because they build their homes in wood rather than soil. These powerful insects use their strong jaws to chew through wood.

Leafcutter Bees are named for their habit of cutting circular pieces of leaves to use as building materials in their nests.

Nesting Habits of Solitary Bees

Solitary bees on small houses-tubules of the cane.

Since there are so many different kinds within the United Kingdom, their nesting habits can vary massively.

Having said this, most species such as Mining bees (Andrena) nest underground. Not only that, but they will make it themselves — alone and hardworking, they deserve far more recognition than they get!

So, how do they make their below-the-surface abodes?

It is all down to the female bee. To start with, she will find the best place for her to start her residency and will utilise her body to dig a single nesting chamber out.

Then, she will insert the pollen that has been touched with juicy nectar into said chamber and lay eggs. At this stage, she will seal it off to keep her egg safe and start on another chamber.

Of course, solitary bees nest by themselves but, if there is an underground spot that is particularly preferable, you can find other bees nests within the vicinity.

Female Sweat bees, in the Halictidae family, sometimes share a common entrance to an underground tunnel system. But each one has her own specific tunnel within that system.

Some species that nest below the ground surface will excavate turrets over the chambers. These can be clearly seen and so, are easier to match with the exact variety of bee.

On the other hand, a few species nest above ground (aerially).

These aerial nesters are the ones that will make use of the man-made nests in your back garden, such as your bee hotels. 

However, they do prefer to utilise old insect nests in trees and such. Usually, they will chew leaves, collect mud or resin or cut parts of leaves off of bushes to seal the holes. 

The Ceratina cyanea, even makes their nest themselves. Typically, they opt for bramble stems to do this and will dig out the pith of the stem and burrow down here. The Ceratina cyanea, common name, Blue Carpenter Bee will even hibernate in the stems during wintertime!

Lastly, three types of solitary bees reside in snail shells.

Yes, you heard us right! They make use of empty snail shells and chew up leaves to seal off the relative sections. Often, they will attempt to camouflage their otherwise vulnerable nest to protect it from the elements and potential predators. Osmia bicolor, the two-coloured mason bee is a type of mason bee that makes its nest from uninhabited snail shells.

Red-tailed mason bee on a snail shell
Red-tailed mason bee on a snail shell

Pollen Collection

Again, because there are so many species in Britain, the way they collect pollen is also varied (like their nesting habits).

The majority of them collect pollen on their legs since they are equipped with special hairs called scopa. They are different from honey bees however, in that the scopa is not pollen baskets. Typically, the pollen they pick up has been made sticky by nectar so it attaches properly to these hairs. 

With other varieties, these aforementioned hairs are located on the underside of the abdomen. It tends to be leafcutter bees that sport this kind of scopa.

The versions with yellow faces do not have scopa or anything on the outside of them that allows for easy pollen collecting. Instead, they will eat it and regurgitate it once they need it.

Our solitary bee friends usually collect pollen from a plethora of plant types which makes them polylectic. Although, a lot of types do prefer to utilise only one (or a few) genera of flowers to gather the pollen from. These are known as oligolecty bees. 

The latter varieties of solitary bees tend to prefer the pollen that is inside the plants that are members of the daisy or pea families. However, polylectic solitary bees favour gardens and farmland where there are a huge amount of plant species blossoming simultaneously (since they don’t mind where the pollen comes from).

Can Solitary Bees Sting?

Male solitary bees do not have a sting at all. But, a female solitary bee will have one. Although, you may be pleased to know that it is an extremely weak one. Not to mention that it will only protrude if you threaten them or touch/hold them roughly!

Since they are not innately aggressive, they are pretty much harmless. Half the time, they choose not to protect their nest either! Basically, you are completely safe with these guys and have no reason to fear these bees.

Wisteria Flowers
Bumblebee on Wisteria Flowers

How can I attract solitary bees to my garden?

As you now know, they like to nest in cavities so, to attract more of them into your garden, you will need to provide a variety of holes (preferably ranging between 2mm and 10mm) for them. Old fenceposts or other wooden slats are great for this. All you need is a drill and you are good to go!

However, if you are not the fence type and do not have any standing bits of wood sitting around, then you could utilise an empty bean can. You will need to put some candle wax into the bottom of it and then fill it with hollow objects. For this, you could try using bamboo canes, straws and other natural odds and ends like stems from plants. Then, all you need to do is hang it up where it is equally as sun-filled as it is sheltered and you are all done!

Providing a bee hotel is another great way to replicate nesting habitats to attract more of these pollinators to your garden. Although, your efforts in installing a bee house won’t be attractive to those who nest underground. These guys want loose soil or mounds of sand.

To provide for these species, you need to ensure you have exposed soil in your garden that is facing towards to sun. You could even attempt to start holes yourself by poking a cylindrical object into the earth.

Of course, using artificial nests will be as good as their natural habitat (regardless of how soul-destroying that may be for you!). Having said this, you can plant flowers that are abundant in nectar to enhance your garden environment for much-needed bees. Remember, the flowers you sow must provide a great supply of nectar and pollen for the entire year. 

While solitary bees may seem a bit mysterious or intimidating at first glance, these fascinating creatures are a crucial part of our ecosystem. If you want to learn more about the many types of solitary bees found in the UK, check out this book for everything you need to know!