So, you have heard of bumblebees and honey bees, yes? But, did you know that there are such beings as solitary bees? No? We thought not! 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 possible categorised them as a honey bee, right? Or, perhaps you didn’t think much of it. Well, either way, these are called 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 of them are actually solitary bees.
In the United Kingdom, we have about 270 varying bee species — a whopping 250 of which are solitary bee varieties! 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, how do you know which ones use which materials? You’ll have to read on to find out!
How to Identify Solitary Bees
As a rule, bees are fluffier than wasps which is a handy fact to know when identifying what is buzzing around your picnic table!
However, distinguishing bee species can be difficult. Plus, solitary bees come in wildly different shapes and sizes. The best way to figure out if you have solitary bees in your area is to have a gander at what they use to seal off their nesting chambers.
Nesting Habits of Solitary Bees
Since there are so many different kinds of solitary bees within the United Kingdom, their nesting habits can vary massively.
Having said this, most of the solitary bee 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. 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 an egg. 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 multiple 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 guys are the ones that will make use of the man-made nests in your back garden.
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.
One of the solitary bee species, 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 females and males of the Ceratina cyanea kind of bee will even hibernate in the stems during wintertime!
Lastly, three types of solitary bees reside in snail shells.
Yes, you heard us right! These bees 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.
Solitary Bees and Pollen Collection
Again, because there are so many species of solitary bees in Britain, the way they collect pollen are 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 do not form a basket. Typically, the pollen they pick up has been made sticky by nectar so it attaches properly to these hairs.
With other varieties of solitary bees, 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.
Solitary bees 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 plants blossoming simultaneously (since they don’t mind where the pollen comes from).
Can Solitary Bees Sting?
The male solitary bees do not have a sting at all. But, the females do 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.
How to Grow a Solitary Bee-Friendly Garden
As you now know, solitary bees nest in cavities so, to attract more of them to 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!
Although, your tin can efforts won’t be attractive to those solitary bees 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, nothing you make yourself 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 the much-needed solitary bees. Remember, the flowers you sow must provide a great supply of nectar and pollen for the entire year.
If you aren’t already green-fingered, you may not know which plants to grow in order to provide year-round pollen. Luckily for you, all you have to do is take a look at our handy lists below and pick a few from each column!
The Early Flowerers
- Bell heather (Erica cinerea)
- Flowering currant (Ribes sanguineum)
- Pussy willow (Salix spp.)
- Wisteria (Wisteria spp.)
- Crocus (Crocus spp.)
- Hellebore (Helleborus spp.)
Insider hint: wisterias are beautiful and, regardless of where you live, it will enhance the aesthetic of your property like nothing else
The Mid Flowerers
- Bergamot (Monarda spp.)
- Globe artichoke (Cynara scolymus)
- Lavender (Lavendula spp.)
- Knapweed (Centaurea nigra)
- Tufted vetch (Vicia cracca)
- Snapdragon (Antirrhinum majus)
- Hollyhock (Alcea rosea)
- Foxglove (Digitalis purpurea)
Insider hint: most people have foxgloves in their gardens already, so if your neighbours have them, try and go for something else so you can provide a different source of pollen for your neighbourhood.
The Late Flowerers
- Everlasting pea (Lathyrus latifolius)
- Ivy (Hedera helix)
- Sunflower (Helianthus annuus)
- Thyme (Thymus spp.)
- Ice plant (Sedum spectabile)
The Long Flowerers
- Dead nettle (Lamium spp.)
- Purple tansy (Phacelia tanacetifolia)
- Chive (Allium schoenoprasum)
All the herbs on these lists will benefit you and your cooking too! Just because you are trying to attract solitary bees to your garden, doesn’t mean you can’t plant things that will help you too!
If you make sure to provide the year-long pollen and you have done all you can to give the bees the right habitats, there is no reason why they won’t flock to the utopia that is your back garden!