Furthermore, they, and their pollinator comrades, including moths, butterflies and hoverflies, are responsible for the success of food crops as diverse as tomatoes, apples, strawberries, chocolate and coffee. Indeed, conservation charity Buglife estimates that 84 per cent of EU crops, valued at a whopping 12.6?billion, depend on pollinators. What are they doing when you are not looking at them? If there are 50 bees on the geraniums, where are the other 40,000 members of the colony?
But the news is relentlessly bad. On an international scale, bee populations are plummeting and colonies are collapsing. Bees suffer from changing land-use and the widespread use of neonicotinoid pesticides. The way we manage them does not help, either. Hives, operated as honey-production units, are dropped into monocultures an extreme example being the large almond orchards in California where any competing flowering plants are sprayed off, and all the honey in the hives replaced with sugar syrup the bee equivalent of asking us to thrive on a diet of bacon and doughnuts.
When it comes to varroa mite, some strains of bee excel at cleaning themselves and getting rid of the parasite and its attendant viruses. Yet domesticated bees are bred for docility and honey production often at the expense of survival skills.
But are bees doomed and is there anything we can do to help? Fortunately, there is a considerable amount of research going on into pollinator health. At the National Botanic Garden of Wales, Dr Natasha de Vere heads up a team of PhD students.
We are looking at bees favourite plants and, given any plant at all, what do they choose? says Natasha. Which is a really simple question, but it is very difficult to answer. What are they doing when you are not looking at them? If there are 50 bees on the geraniums, where are the other 40,000 members of the colony?
Pollen-deprived bumblebees may speed up plant blooming by biting leaves
Until now, many assumptions have been made about what bees eat, based on observation of a fraction of a percentage of the occupants of a hive. The news from the Botanic Garden of Wales is that we may only think we know what bees feed on.
You miss the things you don't see when they are up in the trees or doing something unexpected so we are tracking where bees have actually been, explains Natasha.
Using a drone, the scientists have created general maps of the garden and each month a team of wildlife conservation volunteers note each plant that is in flower and its location.
The study literally hangs on manpower, says Natasha. It takes 15 volunteers plus four students 10 days each month. And the beauty of doing it in the Botanic Garden is that there are around 8,000 different plants. We offer the bees a big smorgasbord and see what they fancy.
Going native
The researchers track floral visitation by analysing the pollen that becomes trapped in the honey. The team matches the genetic material from the trapped pollen with a computerised database to reveal a list of the plants that the bees favour. They have also analysed honey samples from around the UK.
If bees only have access to a very limited range of pollen, they become too malnourished to survive under today's level of pressure. We want to discover what they need, to have the best chance of survival
The early results are illuminating. It transpires that of all the plants in season, the bees use only a relatively small number samples taken in April and May 2015 yielded just 39. Within this, the majority of the pollen comes from native plants of meadow and woodland, with a longer list of smaller quantities from other species, including garden plants.
But they don't necessarily visit the plants we thought they would, says Natasha. Wind-pollinated grasses and trees appear much more frequently than anticipated, at 14 per cent. Oak and sycamore are actually very important.
And then there are weird and wonderful things that come up, like really high levels of spores of the lady fern, Athyrium, which appears in 10 per cent of samples nationally. It could be an accident, but both spores and pollen are a good source of protein . it is a bit like discovering that lions supplement their diet with ostrich eggs as well as hunting antelope.
The decline in bees is down to the interaction of a range of factors, she continues. And it is this perfect storm that leads to colony collapse. Nectar mostly provides energy, but different pollens contain different combinations of amino acids and minerals, which together make up a balanced diet. If bees only have access to a very limited range of pollen, they become too malnourished to survive under today's level of pressure. We want to discover what they need, to have the best chance of having the immunity to fight off diseases.
Selecting the right plants
The findings will also allow gardeners, farmers and environmentalists to hone their conservation strategies.
What we have learnt from this is that native hedgerows and woodlands are absolutely vital, and, as gardeners, there is also a lot we can do
Observations such as bees like geraniums can now be backed up with science. If the truth is bees like geraniums a bit (10 per cent of honey samples), but they like goldenrod and Prunus species a lot more (35 per cent and 50 per cent of samples, respectively), it means that pollinator-friendly seed mixes and plants can undergo some tailoring to ensure a balanced level of nutrition.
Given an optimum environment, like the National Botanic Garden of Wales, it is clear that bees are more selective than was previously thought. And certain flowers have been revealed as much more significant than we realised.
For example, dandelions appear in 85 per cent of honey samples and can be a critical resource for honeybees and other pollinators if the weather is poor. Apple blossom and clover are important in spring; and both hoverflies and honeybees use bramble a lot. It could therefore be argued that, for gardeners, not mowing the lawn in April and planting the right sort of tree is as helpful as making a bee-friendly border for summer.
What we have learnt from this is that native hedgerows and woodlands are absolutely vital, and, as gardeners, there is also a lot we can do, says Natasha. People are very excited about this they really want pollinators in the garden.
Bees don't eat what we thought they did; they eat a lot of things that we were not expecting, some of which are quite a surprise. This means that our bee-friendly gardening may have have been a bit less effective than we thought. The bees know what they need to eat, but we have just been guessing, sometimes correctly, sometimes less so. However, thanks to the National Botanic Garden of Wales, we now know a bit more.
