Bees play a big role in our world as pollinators, but are they endangered? How does a real ‘hive mind’ work? And what’s a waggle dance?
It happens in the cool of night, the largest movement of livestock in Australia. Ahead of spring, honey-bee hives are loaded into netted trucks that follow the flowering of crops ready for pollination. The precious cargo includes queen bees, the linchpins of any hive, and thousands upon thousands of workers that serve them – and us.
Bees are remarkable creatures, who build their homes out of waxy hexagons and communicate through what’s known as a waggle dance. Humans have turned bees into extremely efficient biological machines. Without bees, we would miss a lot of the nuts, fruits and vegetables we enjoy. And if bees go out of action, we can see prices go up in the crops they were meant to have pollinated.
But bees are also buffeted by the vicissitudes of modern life: a crumbling native environment, extreme weather and disease. Plants are cleared to make way for development. Floods wash away hives; fires destroy them. And the varroa mite has led to thousands of hives being destroyed since it appeared in June in New South Wales.
So, how are bees faring? Are queen bees really the boss? And what is a waggle dance?
A European honey bee.Credit:Getty Images/Monique Westermann
How do bees live?
Most of Australia’s 2000 or so native bee species don’t make honey. The blue-banded bee is one. With its glittery blue and black abdomen and green eyes, it is a solitary operator that generally nests in tunnels in sandstone banks where other females have nested before. There are 14 species of blue-banded bees recognised in Australia. The most common bee in the nation, and the one that makes much of the honey you buy at the supermarket, is a European import – Apis Mellifera, or Western honey bee, introduced in 1822.
There are up to 40,000 bees in a European honey-bee hive. Their pheromones (chemicals released by the bees) represent one of the most advanced forms of communication among social insects, says Dr Cooper Schouten, a bee expert at Southern Cross University. “Honey bee pheromones are involved in almost every aspect of the honey bee colony life: development and reproduction (including queen mating and swarming), foraging, defence, orientation and the whole integration of colony activities, from foundation to decline.”
On a typical day, the males, called drones, eat honey and wait to mate with the queen while the females take on multiple roles: foraging for pollen (bees can visit up to 5000 flowers a day), cleaning the brood (baby bee) cells for more eggs to be laid, feeding the young, building the wax cells in which “babies” or honey go (bees secrete wax). Females also attend to the queen.
“They will even decide collectively to kill the existing queen and make a new one if she’s not performing.”
The queen might seem the captain of all this industry, but a beehive is actually one of the “purest forms of democracy”, says Schouten. “All of the worker bees work together to collectively find information and then make decisions based on that information. They will even decide collectively to kill the existing queen and make a new one if she’s not performing.”
If a queen dies, the workers will choose some larvae and feed them highly nutritious royal jelly until one emerges – at which point, this one will kill all the other larvae contenders to the throne.
About a week later, the new queen takes her maiden flight – during which she is inseminated by up to 15 drones. Together, they provide her with enough sperm to last her lifetime; they die soon after mating, each one crashing to the ground. After returning to the hive, the queen will lay up to 2000 eggs a day. “She lays eggs all day long. As much as her own body weight each day,” says Schouten. “And then the worker nurse bees feed her, tend to her, keep her clean and look after her.” While worker bees may live for only six to eight weeks, a queen can live for up to five years.
Honey itself comes from nectar, the sugary fluid made by flowers to attract bees (more on that below). Bees have pollen sacks on their legs, known as corbiculas, which they stuff full before returning to the hive to feed the others. If a bee discovers an abundant area or high-quality pollen, they share the information through a unique form of communication: the waggle dance.
The waggle dance was discovered by Austrian scientist Karl von Frisch, who was awarded the Nobel Prize in 1973 for his discovery. It’s a kind of code that tells other bees the direction, quality and distance of pollen: the direction of the dance tells where the pollen is in relation to the hive; the length of the dance conveys how far the bees will need to fly to find the pollen; the enthusiasm of the dance tells the bees how good the pollen is. Great pollen, and the bees will dance their little pollen socks off.
A looped clip of a bee doing the waggle dance.Credit:Flow Hive/YouTube
Once a bee has dined, in its stomach the nectars’ sugars break down into simple ones that the bee regurgitates into honeycomb cells. After making a “deposit”, the bee flutters its wings to dry the nectar, reducing it to about a fifth water – honey is a “supersaturated” solution of complex sugars and water.
This is why crystallised honey is not spoiled, Schouten adds. “There’s simply not enough water in honey to keep all of its sugars dissolved permanently,” he explains. “Little particles such as pollen, beeswax, bee glue and other nutrients are part of the reason that raw honey is more likely to encourage the formation of crystals. You can simply put your jar of honey in warm water for 30 minutes and stir it up if you want to return it to its natural state.“
Once the honey is reduced, the bee caps the cell with wax; protected like this, honey can last indefinitely. Why are the cells shaped as hexagons? The shape allows for the maximum volume of honey to be stored using the least amount of building resource. “If they were any other shape they’d be wasting wax,” Schouten says. “And why does this matter to a bee? Because wax is extremely valuable and energy-intensive to produce. Bees use about six kilograms of honey to produce one kilogram of wax.”
Almonds in bloom in country Victoria.Credit:Erin Jonasson
What makes bees so useful to people?
It’s not just the honey. While bees are attracted to flowers by the sugary nectar, that’s just a treat, the by-product of bees transporting pollen that enables the plants to reproduce. Pollen is produced by male flowers, or male parts of flowers, and taken via bee to a female flower, or female part of a flower, where fertilisation occurs. It is only upon fertilisation that many plants produce the fruit, vegetables and seeds we eat.
As well as pollinating native plants, native bees also pollinate some crops. They made up one-third of the pollinators at a pear farm in Adelaide Hills in 2022, for example; and in Coffs Harbour in NSW, wild stingless bees were one of the two most abundant pollinators of blueberries. Certain species, such as the blue-banded bee, are adept at buzz pollination, using vibrations to collect pollen from flowers which, coincidentally, fertilises the flowers at the same time.
“The European honey bee is a workhorse. We raise it like we do livestock.”
But it is still mostly the European bees that are trucked around to service crops ranging from citrus fruits and berries to avocados and almonds. The industry operates in semi-secret, says Liz Barbour, CEO of the Cooperative Research Centre for Honey Bee Products, in part to stop people stealing the bees. (Hive thefts, for example, have hit the news in Cornwall and California in the past few months.) “Beekeepers don’t want people to know where they are.”
The honey bee and pollination industry supports 1800 commercial beekeepers, each with an average 299 hives that service some 35 agricultural and horticultural industries, according to a 2021 report by industry group AgriFutures Australia. Some 26,400 hives are needed to pollinate apples in Australia each season, for example, nearly 50,000 hives for macadamias, 40,000 for mangoes.
To keep their hives operating efficiently, beekeepers are always chasing “peak nectar flow”, says Barbour. A typical flowering season will last only a few weeks so almost as soon as the hives are placed on a farm the beekeeper is looking for his next job.
“The European honey bee is a workhorse. We raise it like we do livestock,” says Dr Tim Heard, former CSIRO research scientist, adding that people “just kind of take it for granted”.
(Bees are not the only pollinators. Flies, for example, can be the main visitors to flowers in avocado crops in the Sunraysia region and mango crops in the Mareeba region of Queensland, according to AgriFutures Australia. Birds, bats and the wind also play their part.)
A varroa mite feeding on a honey bee.Credit:Cooper Schouten/Southern Cross University
What does the varroa mite do?
As the mite’s scientific name suggests, varroa destructor is the world’s most destructive honey-bee pest. A tiny red-brown parasite that feeds on developing babies (called pupae) and adult bees, it is found around much of the world. “It would be like you or me having a basketball-sized tick on us,” says Schouten.
The adult female mites sneak into honeycomb cells and lay eggs that hatch and latch on to larvae and adult bees alike, feeding off haemolymph (insect blood). The mites also spread viruses to the bees, much as mosquitoes spread malaria, which can be often a bigger problem than the mite itself.
“This has caused the collapse of wild-bee populations throughout the world,” says Australian National University bee expert Professor Sasha Mikheyev. “A colony is like a densely packed city. Diseases can spread very rapidly.”
So alarm bells rang when varroa was detected in surveillance hives at the Port of Newcastle in June and then across NSW. It is the largest-ever incursion, leading to an industry-wide lockdown. Bee movements were no longer allowed without a permit, and some 12,000 hives – both managed and feral – have since been destroyed.
“Australia has an incredible quarantine system. But one-millimetre living things have a way of finding the cracks.”
“It’s a one-millimetre mite that can live on a bee,” says Associate Professor Patrick O’Connor, an ecologist in the Centre for Global Food and Resources at the University of Adelaide. “Australia has an incredible quarantine system. But one-millimetre living things have a way of finding the cracks.”
There are knock-on effects too. Victorian beekeepers were banned from bringing in hives or equipment from NSW and some were unable to retrieve hives they took to NSW before the outbreak was detected. In August, Victoria’s almond industry was expecting to deliver $600 million in value, but was about 70,000 hives short of the 150,000 it needed.
Varroa does not pose an existential threat to the honey bee industry per se, says Mikheyev, as many countries operate thriving pollination industries where the mite is endemic. But it does require chemicals and more labour to control it, and that adds to the cost of pollination, which ups the cost of fruit and vegetables. The “good news”, he says, is, “We’re the last continent [apart from Antarctica] not to have varroa so we have decades of experience to borrow from other places.”
A native carpenter bee. Credit:iStock
What are the dangers for bees?
Colony collapse disorder (CCD) is where worker bees disappear en masse from a hive. They leave the queen with food supplies and nurse bees to care for her and any younger bees but the hive can’t go on without the workers to maintain it. In the early 2000s it was the most pressing issue for bees but Australia largely bypassed it because of the absence of the varroa mite.
In the United States, bee expert Dr Judy Wu-Smart says CCD did put a spotlight on bees. “Colony collapse disorder was definitely this phenomenon that went through the media, and social media, really bringing public awareness to the plight of bees and the importance of bees,” she says.
Wu-Smart, herself a beekeeper, says bees are a delicate indicator of problems in any particular environment. In her home state of Nebraska, a leaking ethanol plant in her area caused “multiple years of die-off” in her own hives. “My bees were a red flag that there was something seriously wrong in the landscape,” she says.
Insecticides, fungicides and herbicides are another serious hazard for bees, with spray drift a particular problem. Plants or trees that aren’t flowering are often sprayed with pesticides to protect them from insect infestations but the spray can drift onto flowers where bees collect pollen; bees can even carry the poison back to the hive.
And floods, bushfires and drought are no less dangerous for bees than other creatures in Australia. Droughts are especially harmful to bee populations; bees use about two litres of water a day to thermo-regulate the hive. But it’s land clearing for urbanisation that is one of the greatest threats to native bees, says Heard. The loss of green corridors – in areas ranging from desert to rainforest – destroys both food sources and places for nesting.
There are about 20,000 described species of bee alone, and that makes it hard to generalise about their future.
In January 2021, a team of researchers based in Argentina, the United States and Germany published a paper in One Earth that made headlines: Worldwide occurrence records suggest a global decline in bee species richness. The researchers used the Global Biodiversity Information Facility, an international project that is trying to build a detailed database of life on Earth over time using data ranging from old museum specimens to scientific papers and even smartphone photos. Despite the advent of citizen science, since the 1990s the number of bee sightings has been dropping sharply, the researchers found.
That’s the broad context. But in the insect kingdom, there are about 20,000 described species of bee alone, and that makes it hard to generalise about their future. Some are endangered, others aren’t, and for most species we simply don’t know. Australia could potentially have up to 2500 different species of native bees but, according to Taxonomy Australia, many species could become extinct before they are even discovered. “We know a fair bit about bees, but there is a huge amount that we don’t know, and one of the things we don’t know is how many of our species are threatened,” says Dr Tobias Smith, founder and director of Bee Aware Brisbane.
Benjamin Oldroyd, Emeritus Professor in Behavioural Genetics at the University of Sydney, similarly says the little knowledge we have of Australian native bees is hindering our understanding of what threatens them. “There have been extinctions but no one really knows how many, and it is tragic because they are a keystone species,” says Oldroyd.
Still, insects are a vast and adaptable group. “If you look back at the medieval chronicles, there’s always talk of bee plagues, all the bees dying,” says Mikheyev. “And they are still here. Like all insects, they are capable of huge population variation.”
A blue-banded bee.Credit:iStock
Is it true that if bees die, we die?
“If the bee disappears from the surface of the earth, man would have not more than four years to live.” This quote, which did the rounds when colony collapse was at it worst, is often attributed to Albert Einstein but “there is zero evidence that Einstein had an interest in bees,” says Smith. And the quote is incorrect. If bees became extinct, “the planet would change, and we would have issues, but probably humanity wouldn’t die – but we would go through enormous change. The world would become a much more inhospitable place, but we would still eat all these things that don’t require pollination”.
About one-third of the food we eat has something to do with pollination, says Oldroyd. If we were to lose bees, we’d still produce crops such as wheat, corn and rice, but there would be a “massive reduction in the food supply and the food quality, and some crops would be decimated,” he says. “Almonds are the poster child because they 100 per cent rely on bees.”
If bees were to die out, at the very least “we will feel a crunch in our wallet,” says Wu-Smart. “That can lead to human health issues because healthier foods are less accessible.”
Similarly, Heard says that “we will have less food, more expensive food and possibly a lot of the foods that people love and are highly nutritious will be gone.”
In any case, at a time when humans are trying to sustain food growth for a rapidly expanding human population, “it’s an enormously risky thing [to let bees die]. We don’t really understand what the full outcome of it [would] be. It’s too important for us to take risks with.”
What’s next for bees?
The US and other countries have looked into robotic bees for pollination but, for now, it is costly. Similarly, genetically modified super bees that are more resilient to threats such as pesticides have been researched. These “Frankenbees” are yet to be viable and even if they were, many bee researchers are worried that a genetically modified bee would disrupt the natural balance of ecosystems.
With an uptick in crops grown in greenhouses now in Australia, where European honey bees don’t do well, not-for-profit research and developer, Hort Innovation, is using drones in trials in self-fertile crops such as strawberries and tomato plants. As the micro-drones (about 15 centimetres in diameter) hover over the crops, the air vibrates the flowers, encouraging them to disperse pollen.
As for the role that humans can play in helping bees remain a vibrant and healthy part of our ecosystem, Smith says there are a few simple things people can do to help them thrive.
“Bees are very cute, fascinating little insects and they also hold everything together.”
These include weeding home gardens by hand rather than using weed killer because, says Smith, “even organic ones can still kill insects”. And, in those gardens, Smith says “ideally we would plant a diverse range of native plants because different bees have different tastes. They need a diverse diet.”
And if native plants are too expensive, or you don’t have the space, then planting edible herbs and allowing them to flower can help bees too. Gardeners can research which bees live in their area – having an understanding of which plants and colours certain bees are attracted to can make a big difference. The blue-banded bee, for instance, is said to be attracted to blue and purple flowers.
“Bees are very cute, fascinating little insects and they also hold everything together. Once you know them, you can’t give up on them,” says Smith.
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