In honour of World Bee Day, Alison Benjamin, co-author of The Good Bee: A Celebration of Bees and How to Save Them (£9.99, Michael O’Mara Books), has collected five excellent facts about one of the most vital creatures in the ecosystem.
There are 25,000 different species of bees
An astonishing 25,000 or so species of bee have evolved to pollinate flowering plants. To put that in perspective, there are around 10,000 species of birds, and around 5,400 different mammals. Most people think a bee is plump, boldly striped with dense fur and a leisurely gait. But these are just bumblebees which account for only 1 per cent of bee species worldwide. Others believe all bees make honey and live together with a queen bee, workers and male drones, but few bees do this.
In fact, most bee species don’t conform to the popular image of a bee. Some are large and round, but many are skinny and small. There are striped ones and metallic, colourful ones and others that are shiny black. Many bees only live for about six weeks, but others can live for years. A few bees are social insects, like ants, living in colonies of up to 100,000, but the majority are solitary bees who nest alone, but often next door to each other.
There are bees that lick human sweat; short-tongued and long-tongued bees; mining bees and furrow bees that nest in the ground; mason bees and leafcutter bees that live in hollow plant stems or tubes; flower bees who prefer old mortar, carpenter bees who excavate a home in tree stumps, and plasterer bees that line their nests with a waterproof substance. And a quarter of bee species have given up on making their own nest but instead take over other bees’ home, like a cuckoo bird. But wherever there are flowering plants, from windswept mountain tops to humid jungles and arid deserts, as well as our gardens and backyards, there will be bees to pollinate them.
The world’s largest bee is the Megachile pluto, or Wallace’s Giant Bee, named after the Victorian naturalist, Alfred Russel Wallace, who first recorded it. It measures 4cm long with a gigantic 6.3cm wingspan and has jaws like a stag beetle. It had not been seen for 38 years and was feared extinct until its rediscovery in 2019 on an Indonesian island, nesting inside an active arboreal termite mound. In contrast, the tiniest bees are less than 2mm long and are members of the Euryglossina (Quasihesma) group native to Australia.
Not all bees sting
Male bees do not sting. This is because instead of a stinger, a male bee has an endophallus, a penis-like instrument for injecting sperm. In contrast, female bees have a sting at the end of their abdomen and will use it to defend themselves and their nest. The worker honeybees, which are female, die when they sting mammals. This is because their sting is barbed, like a fishing hook, that gets lodged in the skin of the assailant and rips the bee’s body apart as they pull apart.
But their sting produces a smell, known as an alarm pheromone, which alerts other honeybees from the colony to attack the assailant. Imagine that a large bear is stealing honey from the bees’ nest. If the bear receives multiple stings it is more likely to retreat. A few honeybees may die in the process of defending the nest, but the colony is saved.
Females of other bee species have a needle-like stinger that they can retract and use again, so they don’t die when they sting. But generally if left alone most bees are docile.
There are 500 or so species of bee whose sting is so ineffectual that they have developed powerful mandibles that can give an intruder a nasty bite. These are stingless bees. Some, like the Oxytrigona or fire bees, can excrete formic acid to irritate their assailants. They will attack in large numbers, finding their way into sensitive body parts such as the ear, nose, eyes and mouth.
Most stingless bees live in the tropics of central and South America. A few are found in Asia, Africa and Australia, although there are likely more species to be discovered. The South American Melipona genus of stingless bee, locally called the abeja criolla, is well documented because the ancient Mayans began harvesting its honey thousands of years ago. Although they make less honey than honeybee species, there is a group of stingless bees in Australia, called the sugarbag bee (Tetragonula carbonaria).
Honey is bees’ winter food
The honeybee colony has evolved to survive in the hive when it’s cold and there is little to eat outside. The bees don’t fly when the thermometer drops below about 13°C/55°F, or in rain, or strong winds. The population reduces from 50,000 in summer to 10,000 or so worker bees and one queen. They huddle together like penguins on ice caps, and shiver their flight muscles to keep themselves and their home warm. They get the energy to shiver from eating their stores of honey which they have built up over the spring and summer by turning nectar collected from the flowers into honey.
- On one flight, a foraging honeybee can visit 200 to 300 flowers of a plant and collect 0.05g of nectar.
- In one day, she can visit up to 2,000 flowers and collect 0.5g of nectar.
- In five days, 10,000-20,000 foragers can bring in 5kg of nectar to the hive for the bees to turn into 1.5kg of honey.
- It takes 12,000 bee hours to make a 1.5kg jar of honey.
A colony of honeybees is thought to fly around 55,000 miles – the equivalent of one and half times around the world – to make just one pound (2.2kg) of honey. A colony needs about 10lbs of honey to survive the winter.
Turning nectar into honey is a two-stage process of chemically changing the sugars in the nectar from complex into simple sugars and then reducing the water content of the liquid down to 20 per cent or less. When complete the honeybees seal the honeycomb with a white wax cap. This keeps the honey fresh in an airtight container for the winter.
Only honeybees and stingless bees make enough honey for their colonies to survive the winter. Other bees die out.
Bees pollinate one in three mouthfuls we eat
Bees and flowering plants co-evolved 100 million years ago. A bee feeds on nectar and pollen from flowers. As she goes from flower to flower, she picks up pollen from the male part of the flower (the anthers) and transfers some of the grains onto the female part (the stigma) of the next flower she visits. This act of pollination enables the plant to produce fruits and seeds to reproduce.
One in three mouthfuls that the average person eats has been pollinated by bees, including most fruits, vegetables, seeds, nuts, herbs, spices and oil crops. Together they supply a major proportion of nutrients in the human diet. In addition, bees pollinate coffee, and fodder crops for meat and dairy cattle, and other livestock.
And it’s not just the food on our plate that we need to thank nature’s master pollinator for: plant-derived medicines such as aspirin and morphine; fibres such as cotton and linen; and trees that supply timber for construction and are the lungs of the planet, are all pollinated by bees. A few crops are totally reliant on bee pollination to form fruits or seeds, but for the most part bee pollination boosts yields of crops by as much as 75 per cent, increases the size and improves the shape, sweetness and shelf-life of ninety commercially produced crops.
A honeybee colony is like a tree
Honeybees live in 50,000-strong colonies. The vast majority are workers, a few hundred in the summer are male drones, and there is one fertile queen bee who is their mother.
Each honeybee is a component part of a highly structured system that entomologists call a superorganism. We like to use the analogy of a tree to explain how a honeybee colony works. A tree is made up of roots, the trunk, bark, branches, leaves, and sometimes blossom. All these parts work together and make up the tree.
If you remove one leaf from a tree, the leaf dies, but the tree continues. The same applies to our individual honeybee visiting a flower. Take her away from her colony and she will die, but the colony continues. The leaf and the honeybee play a similar role, as food and energy collectors.
The tree gets food through photosynthesis, the process by which leaves turn sunlight into sugar, while the honeybee colony gets its food and sugars from the pollen and nectar that its workers collect. Later in the year, the leaves fall from a deciduous tree because the tree isn’t doing much growing in the cold winter months, so there is little need for energy collectors.
Similarly, the honeybee colony doesn’t grow in the cold winter months, so most of the energy collectors – the worker bees – die: the queen stops laying eggs and the colony shrinks to around 10,000 bees. Both the colony and the tree enter a state of minimal activity. When spring arrives, the cycle begins again. The trees grows new leaves, the honeybee queen produces new worker bees, and the systems revert to their energy-collecting ways.
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