~Dr Harry Siviter
Picture a warm summer’s evening. The birds are singing, flowers are blooming and amongst all this you can hear the gentle hum of bees going about their business. Imagine that bee, and most people will think of a bumblebee or honeybee.
And why shouldn’t you? Bumblebees are awesome and society ingrains a love for them from a young age. Pick up any kid’s book and the bees depicted within, will almost certainly be crudely drawn and anatomically incorrect bumblebees. We all love honey, right? So, naturally we think of honeybees when discussing the plight of bees?
However, despite what we think we know about bees, bumblebees and honeybees are oddities within the bee world.
Bumblebees and honeybees are eusocial, which means they live in colonies. They have an egg-laying queen and workers that collect nectar and pollen from flowers, provisioning the colonies developing larvae.
There are an estimated 20,000 bee species around the world and the vast majority of these are solitary. Here in the UK we have an estimated 250 bee species, of which we have one honeybee and 24 bumblebee species. All the other bees in the UK, unnoticed as they might be, do not fall into these categories.
So, what are these overlooked species? Well there are all sorts! Take the . This bee is often mistaken for a bumblebee, as it is cute and fluffy, but it belongs to the Anthophora family and is one of the first solitary bees to emerge in the spring. There are also the miners. Miner bees (as the name might suggest) are ground nesters, my favourite of which is the tawny mining bee, which is a furry, ginger bee, that emerges around April. Anyone who has a bee hotel in their garden will have probably seen mason bees (picture), which can lay their eggs in the tubes of bee hotels, or more traditionally hollow plant stems, which they provision with nectar and pollen, and seal with mud.
At this point the question you may be asking is ‘why should we care about these hipster bees?’ Well, to start with (as you can see from these pictures) they are charming little creatures which are understudied and undervalued.
As everyone knows (and tells me as soon as I say I work with bees), bees aren’t doing that well. Loss of habitat, an increase in bee pathogens, and the use of agricultural insecticides, can all negatively influence bees. But research published this week in Nature Communications has found that solitary bees are faring rather poorly when compared to eusocial bees (such as bumblebees and honeybees).
We can only speculate as to why this is happening. It’s possible that being eusocial buffers bees in the face of human induced environmental change. If a solitary bee dies before it reproduces it will have no offspring. If a eusocial worker bee dies it is likely that her sisters will still be able to reproduce. Being eusocial might therefore be advantageous in a human dominated world.
People are aware of the importance of bees for the pollination of both crops and wild flowers. A cynic might point out that the majority of pollination services here in the UK at least, are carried out by honeybees and bumblebees. So, in a selfish, anthropocentric way, perhaps solitary bees aren’t that important?
This is wrong on many levels.
Firstly, dependence on just a few bee species for pollination services is dangerous. Honeybee colony collapse disorder, in which 1000’s of honeybee colonies died across the western world between 2007-2008 (particularly in the USA), has shown how dangerous dependence on a single species can be. What would be the result if something similar were to happen again? In this case, I suspect we would be very grateful for these ‘back up’ bees. Secondly, there is a plethora of research showing that agricultural crop pollination, and seed set, is improved by the presence of wild bees. However, ignoring this sensible debate, solitary bees are lovely creatures, that should demand our attention and respect, regardless of ‘what they do for us’.
As a bee researcher, I admit, I am part of the problem. In 2 ½ years of working with bees, I have not conducted any research on solitary bees. For a PhD project, bumblebees and honeybees are low risk subject species. They are easy to work with, can be ordered in, and people care about them already – meaning new research will hopefully have impact. This means only a limited amount of research is conducted on solitary bees.
It is difficult to care about a group of animals we are unaware of and researchers, myself included, have a responsibly to understand these bees in more detail and perhaps, more importantly, to relay that information to the wider public.
There are simple ways we can all help – by providing flowers, nesting sites or letting the grass grow a little longer and in doing these things, we create space for these unsung heroines. Putting up a bee hotel is a great way help these bees, and why wouldn’t you? They add something special to your garden and are a great way to interact with wildlife.
Despite the doom and gloom around the world, I am optimistic about bee conservation, at least here in the UK, where the bee conservation movement seems to have real momentum. However, as we move forward, I believe it would be a great shame to forget our solitary bees. These lovable loners need a helping hand, and I think it’s only right we offer it to them.