CHAPTER FIVE

Bees

If you were to visit China’s Sichuan Province in spring, you would be met with an odd sight. Delicately balanced atop tall ladders, placed amid a sea of white flowers, artists with extra-long paint brushes appear to polish pear blossoms. Meticulously cleaning every single flower, whilst delicately reaching up to the outermost branches, requires intense concentration and poise. Yet those doing the painting are no artists. And this act isn’t a labour of love, but born of agricultural necessity.

For millennia, human farmers have relied on a mutual contract with the natural world. In return for a bountiful local supply of pollen and nectar, from a host of different crop species, bees and other invertebrates provided a free pollination service – ensuring healthy returns later in the season for farmers. Over the course of human farming history, this contract has arguably been one of the most lucrative and important in the world, which according to Forbes is now worth over 500 billion dollars every year.

In recent decades, however, humans have tried to cheat on the contract. After all, alongside free pollination, nature has also always taken a cut of the spoils. With the invention of pesticides, humans decided that they weren’t interested in sharing the percentage of crop-land lost to various moths, beetles and flies. And yet, by trying to cheat the system, we fundamentally broke it.

So intensive has the use of pesticides become in Sichuan’s crop-producing region of south-western China, that insect life has all but disappeared. White fruit blossom paints the canvas of this otherwise bleak landscape, but the air no longer hums. The free pollination service once provided by hordes of industrious workers has instead enchained humans to the backbreaking work of manual labour. Carrying a jar of freshly harvested pollen, hung on strings around their necks, and armed with five foot pollinating sticks (adorned with chicken feathers), Chinese labourers now set out every day of the blossoming season to ensure that their farms have a crop later in the year. It is a sorry sight.

Classical ecological dogma describes ecosystems as top-down pyramids; regulated by the most powerful apex predators at the top, with a sprawling triangle of life functioning below. But reimagine that pyramid as a spider web, and you soon realise how cutting any of the strands can have just as great an impact as removing those trophic champions sitting at the top.

In fact, as seen in Sichuan, removing the smallest components of nature can have the most devastating impacts. But sadly, we cannot judge Sichuan. Indeed, the British have sadly become world leaders in bee removal, too. Sterilised through the removal of their herbs and plants; choked, disoriented and killed by neonicotinoid sprays, bees are faring worse in Britain than in most European countries. If we want to restore thriving grasslands, diverse flora and the basic ability to feed ourselves in the future – we must restore the bee machine.

Of all the thousands of bee species around the world, there is one that has been more successful, one on which we more completely rely, than all others – a cornerstone for our own existence: the western honeybee. As you read this, millions of worker honeybees will be out collecting pollen, nectar and water, fulfilling a genetic urge that ensures that, from the moment they hatch, the bees work themselves at such an extraordinary rate that one day they simply fall out of the sky and die of exhaustion. Capable of pollinating the majority of known crop flowers, and critical for the pollination of such foods as almonds, squash, watermelons and many other staple fruit and vegetables, the efforts of these aerial labourers would be sorely missed if they were to disappear. But how did the honeybee rise to become such a workaholic?

A typical honeybee hive can contain upwards of 50,000 individuals. The largest super-hives, which occur naturally in suitable cavities, can host quadruple that. If we attempted to live at such extreme population densities, the result would quickly spiral into catastrophic failure. The secret to the successes of a honeybee hive are manifold, but three things stand out: language, order, and luck.

From the moment an egg is laid by a queen bee, it receives some of the best midwifery in the world. Tended to by young worker bees, the egg is kept at just the right temperature, and just the right humidity, to hatch after exactly three days. The larva has no eyes, no legs and no antennae. At this stage, it is simply a tiny vacuum cleaner – devouring the honey and royal jelly fed to it by older siblings. On the 21^st day, what started off life as a grub the size of a grain of rice emerges from the pupa it formed inside its hexagonal cell as a fully formed bee. Extraordinarily, it emerges like a pre-programmed smart-phone, fully coded to carry out the functions it will stick to for the rest of its working existence.

The bee brain measures just a single cubic millimetre. Packed within that are a million neurons: a tiny super-computer that produces one of the most beautiful languages yet discovered. Famously known as the ‘waggle dance’ – this vibratory, olfactory and auditory performance is completed entirely in the dark of the hive interior – yet allows a worker bee who has found a good pollen supply to tell its comrades exactly how far and in what direction they must fly to find the same.

It is more than evident when watching a healthy honeybee hive on a spring morning – as they funnel out and all fly off, making a literal bee-line – that they know exactly where they are going. The returning bees, so laden with willow, hazel and blackthorn pollen they are barely still airborne, are testament to the success of the discussions being carried out between workers within the hive. But what do the worker bees get in return for all their hard work?

Because it is only the single queen in the hive who lays eggs, the workers themselves never get a chance to reproduce. Once again, it comes down to genetics. The worker bees are all female, and all siblings. Therefore, although they don’t get a chance to pass their genes on through direct reproduction, by helping the hive raise their sisters, a few of which will become new princesses, they are helping pass on their shared genes via this route. And due to a quirk in eusocial insect genetics – they actually on average share three-quarters of their genes with these sister workers and future princesses. Humans only share half of their genes with their progeny. Eusociality has arisen in many different insect species across the world and also in one mammal – the remarkably ugly naked mole-rat of sub-Saharan Africa. Of course, the individual bees don’t ‘know’ about their genetic relationships – so why don’t the workers revolt?

It transpires that this whole society is kept in check by the pheromonal offerings of one bee – the queen. Researchers in New Zealand discovered that a single chemical – homovanillyl alcohol, or HVA – prevents worker bees from developing aversions, helping keep any tendency to revolt in check. Interestingly, HVA is chemically similar to dopamine – the chemical in human bodies that contributes to the feeling of pleasure. This is just one of many hundreds of chemicals working alongside one another to keep the delicate balance of honeybee hierarchy in check. If the queen is weakened, or removed entirely, the whole hive descends into anarchy. If a single bee from a different hive finds herself in amongst the wrong comb, the workers soon determine that something doesn’t smell right, and she is savagely evicted, or worse, simply pulled apart by the defensive hive owners. With thousands of man-made chemicals filtering into the natural world as aerosols, in our water and into soils, the true effects of their interaction with such complex systems as honeybee hierarchy are still barely understood. Safe to say, the effects are likely to be increasingly negative.

The final component to honeybee success comes down to a little luck. Honeycomb must be one of the most instantly recognised natural materials. And it is a brilliantly efficient way of storing honey and pollen – the ingredients that allow honeybees to feed during the winter when the ground is frozen and there is no pollen for many months at a time. Most social bee species overwinter as individual mated queens, which then have to go through the laborious task of starting a new colony come the spring. Many fail. Yet by overwintering with a massive food supply, honeybees have a huge head start as they come out of the winter. With thousands of workers deployed to harvest the early pollen as it becomes available, they rapidly grow their colony in early spring and are soon able to put out their first of many swarms. Without honeycomb, that simply wouldn’t be possible.

The mystery of the exquisitely uniform hexagonal cells has fascinated humans for millennia. The Roman philosopher Marcus Terentius Varro proposed in the first century bc that honeybees build their cells in order to achieve the best economy of material. Charles Darwin further theorised that a swarm that could secrete wax using the least honey would be most successful. But it turns out, the hexagonal structure of honeycomb isn’t perfect, and could actually be down to chance physics.

Most bee species across the world build some sort of cup to store nectar. Bumblebees, veritable giants in the bee world, build large cells from wax to store their food. The early ancestors of honeybees would have used a similar method of food storage during their breeding season over spring and summer. By packing enough of these irregular cylinders into a small space, such that their cell walls touch and fuse, the result is a comb of polygons. Packed together, with walls forced to fuse, the result is a continuous hexagonal lattice. Over time, this has been refined as honeybees evolved and the final result is one of the most exquisite pieces of art in the natural world: honeycomb. This same method of cell construction has independently evolved in paper wasps, who also use a hexagonal matrix to raise their larvae in.

It is a combination of those three things: the efficiency of their language, the intensity of their order, and the latticed shape of their comb structure, that has allowed honeybees to become such productive workaholics and in turn, become our most valuable ally for global food production.

Whilst honeybees may be the economic superstars of the bee world, bumblebees are arguably the most loved, as well as invaluable pollinators of a range of plants. With their stripy suits, gentle buzz and endearing antennae, they have inspired generations of children’s authors, while their image helps sell everything from hand soap to holidays to honey.

For a temperate-thriving species, a warm furry coat is an excellent idea, which even allows the aptly named Bombus polaris to thrive well inside the Artic Circle. However, the downside of this additional insulation is that bumblebees rapidly overheat. Few bumblebees live in the Mediterranean and almost none persist in the tropics. At 44^oC, bumblebees become so overheated inside their extra layers that they die. With climate breakdown advancing global temperatures every year, over the coming decades, our various European bumblebee species are going to be pushed further north on a thermocline of heat extinction. This could be bad news for the many different flora species dependent on their pollination service.

In 1859, Charles Darwin published an observation in his renowned work On the Origin of Species by Means of Natural Selection. It was one that soon came back to haunt him. Residing at Down House, now on the southern outskirts of London, Darwin performed a number of experiments in the local meadows to determine the importance of bee pollination.

Using a fine woven mesh net, he built a series of cuboid cages and placed them over patches of red clover as they flowered, whilst leaving other patches open to invertebrates. His results were utterly conclusive: the uncovered clover produced a healthy seed crop, yet the covered crop didn’t produce a single seed. Darwin wrote ‘I have very little doubt, that if the whole genus of humble-bees became extinct or very rare in England, the heartsease and red clover would become very rare or wholly disappear.’ By Darwin’s era, this result wasn’t a huge surprise – the relationship between invertebrate pollinators and flowers was beginning to be understood, but it was Darwin’s further extrapolation of the impacts of this that stood out. He continued:

The number of humble-bees in any district depends in great degree on the number of field-mice which destroy their combs and nests … Now the number of mice is largely dependent as everyone knows on the number of cats … Hence it is quite credible that the presence of a feline animal in large numbers in a district might determine through the intervention first of mice and then of bees, the frequency of certain flower in that district!

Bees need flowers, as much as flowers need bees. If the pollinating species of bee disappear, the knock-on could ripple through the food web. This is the earliest known example of one of the main staples of modern ecology – a food chain. And it is one that was occurring long before Darwin wrote about it. In meadows and woodlands across Europe, wildcats once provided nature’s finest rodent removal service.

Under barely audible footsteps, these highly tuned killing machines prowl the margins. Every so often, they freeze. Poised, the only movement comes from one ear, deftly rotating to pinpoint the sound of tiny footsteps on wet grass. A slight head-turn tracks the sound as it moves between a tunnel system at the base of the grass. Time ticks, but the wildcat doesn’t move. Every muscle in its body is preparing its next move. The second ear joins the first, both now pointing directly forward – two tiny satellite dishes picking out every hint of sound and converting it into a 3D movement map. In slow motion, the wildcat lifts one front paw, twitches its back feet, then catapults forward with both front feet outstretched. Pinned to the deck, one more rodent is swiftly snuffed out.

In spring, this creates just the right conditions that a newly emerged bumblebee queen is looking for. An empty vole burrow, with a cosy nest of moss and grasses safely hidden at the end of an underground tunnel, is the best place for a bumblebee queen to raise her own family. And so the food web continues. Bees need vole holes. Voles need clover. Clover needs bees. And wildcats help keep the whole system in balance.

Unfortunately for the ever self-critical Darwin, his early theorising turned out to be a little wide of the mark. On learning, after publication of his famous book, that red clover is actually capable of being pollinated by a few different species of bee and therefore a little safer from extinction should its main pollinator disappear, he wrote to his neighbour angerly berating his oversight: ‘I beg a million pardons. Abuse me to any degree but forgive me – it is all an illusion (but almost excusable) about the Bees. I do so hope that you have not wasted anytime for my stupid blunder. I hate myself, I hate clover and I hate bees.’

The variation in size, colour and shape of flowers is extraordinary. From the pinhead-sized Wolffia globosa, the world’s smallest flowering plant, to Rafflesia arnoldii, which produces massive red flowers a metre in diameter and up to 11kg in weight – there are nearly half a million flowering plant species, of every conceivable configuration, in between. Almost all of these have co-evolved with at least one insect pollinator, an arms race in which the flower offers up nectar in reward for pollination and the insects (plus a few birds and the odd mammal) come up with increasingly efficient ways to harvest that nectar. Some nectar-drinkers have learnt to bypass the pollination mechanism entirely, instead drilling a hole through the side of the flower and sipping straight from the nectary. Others use clever electronic cues to determine whether or not a flower has recently been visited by another pollinator – and thus move on rather than expend their energy at an empty bar. Some bumblebee species, particularly when pollen-deprived, have learnt to bite flower leaves to induce their buds to flower sooner. But a discovery in 2018 forever changed the way that we view the ever-evolving relationship between bees and flowers.

The natural world is full of sounds. Whilst some – such as leaves rustling or wind blowing – are easily filtered out and ignored by us, others – such as a bumblebee’s buzz – are distinctive, cutting through the background soundscape to be readily detected by our ears. But it turns out ours are not the only ears processing this sound.

Enter the evening primrose. Producing tall stalks, sometimes well over a metre tall, covered in many ten-pence-sized yellow flowers in the shape of shallow satellite dishes, this garden favourite holds a remarkable secret. When Tel Aviv University researcher Lilach Hadany began to play plants sounds to see how they responded, she discovered that evening primroses have ears. When played white noise, high frequency sounds or no noise, the plants seemed to carry on as normal. But when played bee sounds, or low frequency sounds, the response was unmistakeable. Within three minutes of being exposed to these, the sugar concentration in the plants’ nectar increased from an average of 14.5 per cent to 20 per cent. The flowers could apparently hear the presence of bees and responded by upping their sugary offering. The research is still in progress, but if the pollinators are held at such flowers for longer, increasing the chances of successful cross pollination – it makes sense for the flower to provide this richer reward.

Excitingly, Hadany’s team also ran tests to see how the shape of a flower would respond to different vibrations. Sure enough, evening primrose flowers resonate at pollinator frequencies. As Hadany explains, ‘It’s important for them to be able to sense their environment – especially if they cannot go anywhere.’ It is extremely likely that this new field of study, dubbed phytoacoustics, will yield many more previously unknown relationships between plants and pollinators. In the decades to come, this line of research is likely to only further cement the crucial role that such species play in their ecosystems.

Our social bees are important. They have beautifully complex lives, and ruthlessly efficient societies. Yet every day throughout spring, summer and autumn, bees are being pincered, skewered and plucked from the air. Although they are often armed with a powerful sting, extraordinary reflexes and the power of flight, the natural world certainly doesn’t disappoint when it comes to the army of predators that specialise in the delicate business of bee removal. As a result, social bees are not only a keystone species for the services they provide – but also for the menu that they serve to an array of bee-eating specialists.

If one of our many bee species manages to make it through the suite of parasites that invade their nests, the cuckoo bees that evict their siblings, and the hornets that wait like the school bully outside their nest entrance – they have a chance to set off and find food. But the flowers that they visit can hold a nasty surprise. Occasionally, without warning, the petals of a tasty flower appear to snap shut, trapping a visiting bee which is then dragged down between the petals, never to be seen again. The culprit is not the plant, but a spider.

With its bulbous abdomen, four pairs of muscular legs and eight eyes, a Misumena vatia crab spider is about the size of a common garden spider. But unlike their cousins, these colourful predators don’t rely on a web to catch their prey. Instead, they rely on a brilliant piece of biology. Thanks to specialised pigment cells, these arachnid chameleons are able to completely change their colour to match the petals of the plant they lie in wait on. One week they might be white, nestled around the rim of the ox-eye daisies. Two weeks later, they might be yellow, colour-matching the meadow buttercups. A month on, the very same spider might be pale cream, a spider swatch camouflaged against the flowers of hogweed. Sitting patiently with its front legs held open like a pair of pincers – hence the name crab spider – it waits for its next victim to land. As soon as the prey buzzes within range, the pincers clamp shut, the jaws deliver a venomous bite, and the bee is disarmed. As the spider’s digestive enzymes liquify a million bee cells into protein soup, its fangs work like straws to suck the liquid from its victim.

Should the bee manage to avoid these snap traps hidden in their favourite food, they then have to fly the avian predator gauntlet to get their cargo back to the colony. In mature wood pastures, spotted flycatchers wait on branch outposts, ready to launch aerial assaults on pollen-laden bumblebees. Plucked from the air, the bees are unceremoniously snuffed out, their stinger rubbed against the branch until rendered harmless. In scrubby patches of woodland, shrikes specialise in skewering bees on blackthorn, often alongside a cache of other unfortunate victims including lizards, songbirds and rodents. Now almost extinct in Britain, red-backed shrikes once thrived on our bee biomass.

But of all the species capable of ending a bee’s day, there is one that is better than all others. Graceful, elegant and swift, with a fluting song that sounds like a warm Mediterranean evening and a colour palette that rivals the flashiest Amazonian parrot, the bee-eater is comically cute. A bright yellow bib, a turquoise chest, whisps of blue in the cheeks and a jet-black bandit mask adorn its front. A deep graduated ochre paints its back, leading down to a long and tapering green tail. In the right light, this exquisite plumage shimmers. But good looks can be deceiving. The black pupils in its crimson eyes miss nothing. And its gently curved long bill is a weapon trained to extinguish bees. These birds are rare visitors to our shores, but with warmer summers, the appearance of a few pairs seems to be more frequent, with breeding recorded more times here in the past decade than the whole of the twentieth century. Perhaps one day, showcasing these hungry avian superstars might help fly the flag for the precipitous invertebrate decline we are currently witnessing amongst our social bees.

So our honeybees are economically essential pollinators with incredibly complex lives and our bumblebees are aerial protein parcels being listened to by flowers, but we have barely scratched the surface when it comes to the extraordinary diversity within the wider bee world. In Britain, over 90 per cent of our bee species are neither bumblebees nor honeybees (of which there is just a single European species), but solitary bees. Rarely noticed yet found from Scilly to Shetland, the solutions that these underappreciated creatures have come up with to fit into their natural worlds are both extraordinary and outstanding.

There is a species of leafcutter bee that neatly chisels precise circles into rose leaves, taking up to 40 cut-out discs back as wallpaper for each of her nest chambers. One of our smallest species of British bee likes to bury itself in the head of dandelions, appearing many minutes later completely coated in yellow pollen. There are bees that nest in sand, mud and wood. Cuckoo bees – as their name suggests – attempt to exploit the work of others. Miner bees mine, digger bees dig, mason bees nest in wall holes, and wool carder bees strip the hair from furry leaves and whip it up into a nest lining. But it gets better.

Our smallest bee is so tiny that it nests in the holes left abandoned by woodworms. At just 6mm long, the jet-black small scissor bee is a very particular customer when looking for a home for its eggs. But not as picky as one of its relatives. The metallic-coloured blue carpenter bee digs out the ends of broken bramble stems. But this only works with the help of giants – for they aren’t capable of cracking the bramble stems themselves. A large herbivore shattering dried bramble stems in pursuit of a new feeding opportunity or bedding area reveals exactly what the blue carpenter bee needs – the exposed bramble pith. Carefully boring a hole down into this natural insulation – these solitary bees tuck themselves in for the winter – it hibernates in a well-protected spiky fort and likely hopes that it isn’t awoken by the ground-tremoring footsteps of one of the giants that helped create its slumber-shelter.

Though adorable, there is another solitary bee that wins the award for ingenuity and endurance. The gold-fringed mason bee is as pretty as it sounds – with each leg and abdominal segment embroidered with a fine plume of gold hairs. Each spring, female gold-fringed mason bees set out on a mission, searching for a place to lay their eggs. Flying low over herb-rich grasslands, they frequently dive into the flora to inspect possible sites. But unlike the miners, diggers or masons, these discerning, gilded bees are after a ready-made apartment block. Following one of these bees, and checking what they’re after, you’ll likely be surprised to see they are meticulously inspecting every snail shell they come across. An empty Roman snail shell is discarded – too big. A young brown-lipped snail shell is quickly ignored – too small. Like a tiny Goldilocks testing bear porridge, this shell-shopper is particularly keen on vacant garden snail shells. Once decided, the female bee will lay a few eggs in neatly constructed chambers within the spiral structure of the shell, before plugging up the door with a mastic made from chewed leaf pulp. In a final act of maternal care, she plasters the shell in a fine coat of leaf mastic, a sort of camouflage jacket with a purpose still yet to be discovered.

In 1962, Rachel Carson predicted the devastating effects that a tidal wave of synthetic pesticides sweeping the world would have in her visionary book Silent Spring. She has been proven emphatically right. DDT might be the most notorious insecticide, but some modern neonicotinoids are ten thousand times more toxic. Every year, great swathes of the countryside are coated in a blanket of invertebrate death as sprayers target everything from potatoes deep underground to apple buds waiting to fruit. Time and again, humans continue to try and cheat the natural world, reaping it of its bounty in dangerously over-stretched ecosystems, whilst expecting the whole process to continue without fail. By breaking our natural contracts, we are breaking these systems. Many are now in freefall: some, as in Sichuan, have collapsed. Why should the natural world return free pollination when it is being annihilated by insecticides, herbicides and fungicides? Our global farming systems have become so efficient at doing one thing, they appear to have forgotten that they simply cannot function without natural pollinators.

Bees can bounce back. Like many insect species, their productivity when left to their own devices is exceptional. But this only works at a landscape level. Individual wildlife-friendly farmers are leading the charge but are too often let down by neighbours that insist on using powerful insecticides. If we can repair this strand in the food web, we can reverse the destruction of natural capital occurring all around us.

In June 2018, I awoke in the Carpathian Mountains of eastern Europe to the uncomfortable realisation that I had booked my rural retreat far too close to a motorway or at least, a major road. Sleepily coming to and parting the curtains, then dressing, I struggled to define where the dull, persistent roar was emanating from. Stepping outside, it became quickly apparent that the culprit was not a motorway – but honeybees.

There are few, if any, landscapes left in the UK that reverberate so loudly with pollinating bees that the sound wakes people up in the morning. Whilst the ‘bee-loud glade’ referenced in W. B. Yeats’s poetry is frequently remarked upon, few of us have heard bees as they are supposed to be heard: a purposeful roar, loud enough to get you out of bed.

We are blessed, however, that right now, large tracts of Europe, especially those in eastern countries such as Latvia, Estonia, Poland and Belarus, and those areas dominated by the Carpathian’s mosaic of forests and meadows, such as Slovakia, northern Hungary, Romania and Bulgaria, have yet to fall silent. These landscapes abound not only with bees – but with all that bees create.

In these sympathetically farmed landscapes, where small herds, small crops and zero pesticides or herbicides still conspire to provide enough food for local people, it is not only bees that are common. Turtle doves, on the verge of extinction in the UK, grub seeds from the abundant chickweed, knotweed and fumitory pollinated by honeybees that can number five million within the hives of a single village. It might be easy for us in western countries, with higher populations to feed, to think that such methods are outdated, but they will, in all likelihood, last far longer into the future.

The return of honeybees to our landscapes, in the vast numbers that were once normal, will signal the return of a phenomenon far more important for the recovery of nature than biodiversity: bio-abundance. And the actions of a society of millions, writ large across our landscapes, can, in a very short space of time, rejuvenate those landscapes once again. But as Sichuan reminds us, there is another future. If we continue to ignore the warning signs, we too will soon have to listen to the ever greater silence in our land – and suffer the consequences of our broken contracts.