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8 Insights from Insects
Velcro is a genius invention. We use it on shoe straps, jackets, children’s mittens, and ski ties. It all started with a Swiss engineer who was out hunting with his dog and got annoyed because the mutt ended up covered in burrs every time they came home. That prompted him to take a closer look at those ingenious seed dispersal mechanisms: small hooks that grab hold of passing animal pelts. Hmmm . . . perhaps it was an idea worth copying. And that’s how Velcro came to be.
Engineers and designers are increasingly turning to Nature’s solutions for inspiration. Nature has had billions of years to refine its solutions, and evolution has come up with countless smart structures and functions.
When it comes to shrewd solutions, insects make a strong showing because there are so many of them and they are so good at adapting. We can use them as model organisms, as we do with fruit flies. We can make them do things for us that we can’t do for ourselves, such as crawl into collapsed buildings or help break down plastic. Perhaps they can provide us with new solutions to the antibiotics crisis, improve mental health among the elderly, or even help make intergalactic travel possible. One thing is for certain: we’ll be drawing inspiration from them and imitating them for a long time to come.
According to the Oxford English Dictionary, biomimicry is “the design and production of materials, structures, and systems that are modeled on biological entities and processes.” There are numerous examples of biomimicry that started with insects. Dragonflies provide the inspiration for drone technology. Black fire beetles, which have heat sensors on their belly—they lay their eggs in the embers of forest fires—are being studied by the US army and others with a view to developing better heat-seeking sensors.
One key discovery that offers huge potential is that in many cases, insects’ color is not the result of pigments but of special structures on the surface that reflect certain wavelengths of light. The result is an intense metallic color that shifts depending on the angle you view it from, as with the bright blue morpho butterfly found in the jungles of South and Central America. Knowledge of structural colors may help us create colors that do not fade, as well as improved solar panels and mobile phone screens and new types of cloth, paint, and cosmetics. And banknotes that can’t be forged.
The beautiful longhorn beetle Tmesisternus isabellae, whose only known habitat is a tiny area of Indonesia, changes color according to the atmospheric humidity. When the air is dry, the beetle is gold with dark green stripes. If the humidity increases, its golden coloring shifts to red. Chinese chemical scientists recently copied this trick, applying it to printing technology.
The scientists think their insect-inspired ink can be used to print banknotes that are impossible to forge. If you want to check whether your money is genuine, you can simply breathe on it to see if it changes color. In this way, a unique and rare beetle is helping combat forgery and swindling.
So the only thing left to worry about is keeping your banknotes in a safe, insect-proof place, especially in hot climates, where termites eat anything including even a speck of cellulose—including banknotes. Termites in India have, in fact, chewed their way through a fortune on several occasions. In 2008, they gobbled up all the spare cash an Indian businessman was keeping in the village bank, and in 2011, they chomped their way through piles of rupee bills in a bank vault. The total value was well over $125,000.
Perhaps we can forgive termites for eating a few rupees here and there once we see how much money we can save by copying their architectural solutions. You see, termites have given us some excellent ideas for improving energy efficiency in tall buildings by developing a more natural air-conditioning system.
The enormous termite mounds of Africa can tower several yards above the ground, housing millions of white or pale brown social individuals. Despite the baking heat outside, it is always pleasantly temperate inside the mound. And down in the depths, maybe three feet below the surface, her majesty the Queen of Termites lies in her temperate, oxygen-rich throne room squeezing out eggs at a prodigious rate. All around her, thousands of workers tend the fungus gardens that are like the mound’s industrial kitchen (see page 77), where food is prepared for millions. But the fungus is picky and thrives only in temperatures close to 90 degrees Fahrenheit; no more and no less. How do the termites manage to keep the interior temperature constant?
It turns out that an ingenious system of air channels uses temperature oscillations outside the mound over the course of the day and night to create a draft that runs through the construction. This “artificial lung” ensures that cool, oxygen-rich air is drawn down while warmer air, rich in carbon dioxide, is driven out.
Architects copied the termites’ ingenious design when they built Eastgate Centre, a large office and shopping mall in Harare, Zimbabwe. Although it is one of the largest malls in Zimbabwe, it doesn’t have any regular air-conditioning or heating; instead it uses passive cooling, applying the principles used by termites. As a result, the building uses only 10 percent of the energy that would be consumed by an equivalent-sized building with standard mechanized air-conditioning systems.
You’re probably familiar with fruit flies, those sluggish so-and-sos that form a cloud when they fly up off your fruit. Irritating as they may be, these tiny red-eyed insects are, in fact, the winners of no fewer than six Nobel Prizes.
Their family name in Latin is Drosophila, “one who loves the morning dew,” which sounds a lot more poetic than “fruit fly” and reflects the fact that these insects originally inhabited warm, humid tropical climes. Today, many of the species in the fruit fly family are found throughout the world (with the exception of Antarctica). One common feature of the species that are liable to turn up uninvited in your kitchen is that they thrive on rotting, fermenting organic stuff, such as compost, overripe fruit, or the dregs in the bottom of a beer can. There they lay their eggs and develop at record rates.
Of course, they are pretty annoying. We’d much rather insects left our food alone and stuck to the outdoors life. But these critters are actually more important than you think: the Drosophila melanogaster fruit fly is the uncrowned king of the laboratory and has been a crucial component of research and lab experiments for more than a hundred years.
Fruit flies have many great traits that make them particularly suitable for research: they are cheap and easy to keep in laboratories, go through their life span at a supersonic pace, and have oodles of offspring. What’s more, we have a good grasp of the species’ genetic material or DNA, having fully mapped its genome in 2000. Without wishing to insult anybody, I can reveal that your genes are more akin to those of a fruit fly than you might like. For example, one study that examined a selection of disease-related gene sequences in humans found that 77 percent of them also occurred in fruit flies. It is precisely this similarity that makes fruit fly research such a useful way of understanding various phenomena, even in human beings. The flies have taught us a lot about chromosomes and the way that traits are transmitted. This research earned Thomas Hunt Morgan a Nobel Prize in 1933. Thirteen years later, after being fried with massive doses of radiation, the flies helped Hermann Müller win another Nobel Prize for showing that radiation leads to mutations and causes genetic damage. In 1995, the Nobel Prize in Physiology or Medicine once again went to our wee winged pal along with three scientists whose wide-ranging work showed how genes control development in the early stages of fetal life. In 2004, the prize went to research on the fly’s olfactory system, and in 2011, it went to work on the fly’s immune defenses. In 2017, the fly won its last Nobel—to date—this time for studies of the built-in clock that controls the circadian rhythm of living organisms. These last prizes are particularly good examples of fly research that is highly transferable to us humans.
Even the thing we find most annoying about the fly—its attraction to stuff that is fermenting and preferably contains alcohol—has turned out to be useful. The research into “alcoholism” in fruit flies is a serious and important business but also involves plenty of human parallels that are sure to pep up the conversation at Oktoberfest—such as the fact that excess alcohol makes male flies clingy and sex mad while simultaneously reducing their chances of successful mating. Or that when male flies lose out on the dating market, they “drown their sorrows” by drinking more than male flies who have managed to mate successfully.
As if that weren’t enough, fruit flies continue to increase our knowledge of diseases such as cancer and Parkinson’s disease, as well as phenomena such as insomnia and jet lag. So a bit of respect might be in order the next time you catch yourself cursing the tiny flies in your kitchen. As you set up a fruit fly trap, maybe you can at least whisper a little thank-you to one of the most important creatures in biomedical research.
Bacteria are increasingly developing resistance to antibiotics. This is a large and growing problem; according to the World Health Organization, this causes more than 700,000 deaths every year. Knowledge of ecology and evolution is a crucial tool in the battle against antibiotic resistance, and insects are contributing to the solutions.
Ants are an especially interesting subject of study. They live close together in large societies and need good defenses against bacteria and fungi to prevent the death of the entire colony. This is why ants have two special glands on their bodies that produce antibiotics. They smear it over themselves and their sisters using their forelegs, and experiments have shown that this activity increases when fungus spores are present in the nest.
Leaf-cutter ants—the ones that take home leaves, which they chew up and use as a base for cultivating fungi (see page 77)—face extra challenges when it comes to fungal infections: other parasitic fungi sometimes try to establish themselves in the ants’ fungus gardens. If successful, they can kill both the fungus crops and the ants themselves. So the ants have developed a powerful defense against such invaders: a collaboration with bacteria that live in special pouches on the ant’s body and produce a type of antibiotic that kills the fungal invaders. It is a finely tuned collaboration that has been perfected over millions of years. Studies of this cooperation between ants and bacteria offer us good opportunities to identify effective ways of killing fungi and bacteria. Several discoveries have already been patented, including a fungicidal antibiotic derived from leaf-cutter ants called selvamicin, which is effective against infections by the yeast Candida albicans, a fungus many of us have encountered in the form of oral or genital infections.
I’m always happy to see clothes or jewelry with insect motifs. It doesn’t happen all that often, although a beautiful butterfly or a fluffy bumblebee is sometimes allowed to grace a garment. But flies? Rarely. I carried out a small, extremely unscientific test: an internet search for “butterfly jewelry” in Norwegian resulted in around 1,000 hits. If I switched “butterfly” or “blowfly,” I didn’t get a single hit.
We think of blowflies as vectors of disease, but these insects can actually heal us by feeding off our infected wounds. It sounds revolting, but this is old news. Genghis Khan was a thirteenth-century Mongolian warlord who founded the empire deemed to be the largest by area in the history of the world, stretching from Korea to Poland. He didn’t create this kingdom through diplomacy and negotiations, either, but through brutal and ruthless warfare. Legend has it that Genghis Khan always took a wagon full of maggots into battle with him. They were placed on his soldier’s wounds, which made them heal more quickly so that the men could be sent back to the battlefield sooner.
This kind of larval therapy was also used with great success during the Napoleonic Wars, the US Civil War, and the First World War. After we discovered the fantastic properties of antibiotics, larval therapy sank into oblivion. More recently, though, it has returned to the fore, largely because of multi-drug-resistant bacteria.
The larvae of the common green bottle fly, Lucilia sericata, are the ones most commonly used for this purpose. This fly can be found outdoors throughout the United States. When used for medical purposes, it is essential for the maggots to be sterile before they are placed on the wound, so they are bred in special laboratories. The maggots are often placed in a kind of coarse-meshed tea bag to ensure that they can’t escape but are still able to stick their heads through the mesh to get their job done. And their job involves multitasking. The larvae limit the growth of the bacteria in the wound by producing antibiotic-like substances, and substances that alter the pH value of the wound. They also eat the dead wound tissue. In some cases they have also been found to produce substances that promote the growth of new tissue. They eat only dead tissue and pus and do not touch the living tissue around the wound.
One of the more creative experiments involving blowflies was conducted in the early 1900s by the “Maggot King,” an Englishman who believed it was wholesome and healthy for people to inhale the vapors of fly larvae. The man had tuberculosis but was convinced that the maggots he bred as bait for his frequent fishing trips were what kept him alive. And he was keen to share his knowledge with other sufferers. So every summer, the Maggot King had several tons of dead animals sent to him, generally from zoos. He would leave them outdoors until they were full of maggots, which he harvested, transferred to special containers, and then placed indoors in what he called maggotoriums, wooden shacks where patients could sit among the containers of maggots and stinking rotten meat, entertaining themselves with a book, a game of cards, or a friendly chat with the other invalids.
I’m sure few readers, if any, will be surprised to hear that this business idea really stank. People could smell the stench of the Maggot King’s farm for miles around, and his views garnered little scientific support. Although several patients actually testified that their health had improved after spending time among the rotting animals, the inhalation of maggot gases never became a commercial success.
But maybe the future will show that the Maggot King was not entirely on the wrong track. Blowfly larvae can apparently produce gaseous emissions that limit the growth of a nonpathogenic relative of the tuberculosis bacterium that is often used as a test organism. Pending further research, those who use live bait for fishing might as well draw an extra deep breath over their maggot tins, just for the sake of their health.
Insects can also help our mental health. It is common knowledge that keeping pets can improve your happiness and health, and in the East, people have kept insects as pets for thousands of years. In China and Japan, in particular, people have often kept caged crickets, relatives of the grasshopper. The primary attraction was their beautiful song, but in thirteenth-century China, it was also popular to hold cricket fights. Indeed, an annual two-day cricket-fighting championship is held in China to this day. And it is just one of more than a hundred traditional Chinese festivals associated with insects.
It is not an uncommon hobby among Japanese children to catch (or, if they live in a town, buy) large male beetles and arrange fights between them. We’re talking about some of the planet’s largest beetle species here, with powerful horns or long mandibles, which the males use to fight. In Japan, as in the United States, bus tours are arranged so that people can see fireflies (which are beetles, not flies) dancing in the night at special locations.
Now insect pets are being tested as a method of geriatric care—in Asia, of course. Because what happens if elderly Koreans have a cage full of crickets placed in their charge?
Nearly a hundred Koreans with a mean age of seventy-one were tested for psychological factors such as depression, anxiety, stress level, sleeping difficulties, and quality of life. After that, they were divided evenly into two groups. While both groups received guidance on healthy living and weekly follow-up telephone calls, only half of the subjects were given a cage that contained five chirping crickets. The species in question was Teleogryllus mitratus, a garden cricket that lives in Southeast Asia, whose “song” is considered extremely beautiful and pleasing to the ear.
After two months, all the participants were interviewed and tested again. Almost all the old people liked their crickets, and three-quarters of them felt that caring for the insects had improved their mental health. The test results also showed a slightly positive effect on several of the factors that were measured, in particular a reduced level of depression and an improvement in quality of life.
The good thing about a cricket in a cage is that it is cheap to buy and needs little looking after. The old people don’t have to take them out for air, clip their claws, or groom their coats. Yet it can be rewarding for them to watch the cricket shuffle around in its cage and sing, and it needs a bit of food from time to time. In fact, it needs you, which is good to know. Caring for a cricket can be the little bonus that gives daily life some meaning for people who are in poor physical health, can’t do much, and spend a lot of time sitting alone.
Fortunately, it seems as if interest in insects is also growing in the West. Many people have become aware of buzzing bees and chubby bumblebees. People are planting nectar-rich flowers, hanging up insect hotels, and building bumblebee nest boxes in their gardens. Many insect lovers are doing an important job by seeking out and collecting (or photographing) insects from new places. It’s like a treasure hunt that offers rewarding experiences of nature while increasing our knowledge of insects.
In several places, particularly in warmer climes, you can find butterfly houses, large areas enclosed in a net where butterflies can fly around freely, being admired and photographed. One Norwegian nature photographer, Kjell Sandved, who worked at the Smithsonian Institution in Washington, DC, became world famous for his butterfly alphabet, beautiful close-ups of butterfly wings displaying letters. The overwintering habitats of the monarch butterfly in Mexico draw tourists from all over the globe, and in 2016 half a million people visited New Zealand to admire the luminous fungus gnat larvae in the ceiling of the Waitomo Caves.
These phenomena highlight an issue that concerned the famous insect scientist Edward O. Wilson: the need we human beings have for a deep and intimate connection to nature and other species. Wilson called it biophilia, the love of living things. He thought it was a trait that had developed and been reinforced throughout our evolution because it increased people’s chances of survival to be in close contact with nature. If you paid attention to flowers, you could find their fruit a few weeks later. And if you were familiar with the species that could harm you or kill you, your chances of survival rose. Many think that our dislike of snakes and spiders can be traced back to this kind of adaptation.
Nowadays, ever more research confirms how important it is for human health and well-being to be close to nature. Older people survive longer if they live close to a green area, regardless of their socioeconomic status. Students learn better if they can see a patch of green outside their window. Children with personality disorders have fewer symptoms after pursuing activities in nature. It was found that when people moved into public housing were randomly distributed between housing with green areas and housing whose outside areas were paved over, those in housing with green outer areas experienced less violence in the home.
When my children were in elementary school, I used to get to join them on trips to the stream in springtime. Small, skeptical ten-year-olds would watch me use a metal sieve on a long pole to fish up brown mud, which I would tip out onto a white plastic tray on the ground.
“Yuck! You’re not going to touch that, are you?” somebody whines. But then the miracle happens: the mud settles, and teeming life emerges. Together we gaze at whirligig beetles with two pairs of eyes, which allow them to see clearly both above and below water, and talk about how the silver bubble on the rear end of another beetle is an air bubble that it’s breathing in.
Suddenly there’s a battle for the plastic tray and the sieve. Everybody wants to find the strange bugs. Forgotten are the cloth shoes that won’t withstand the water; forgotten is their fear of getting mud beneath their fingernails.
Those days have left me with good memories, filled with an intense sense of having contributed to something meaningful.
More than half of the world’s population now lives in cities, and the number will only increase. Many lack opportunities to visit wilderness areas or have close encounters with wild animals. Luckily, local wildflower areas and urban green spaces can be excellent examples of the natural world, and you’re guaranteed to find insects there.
New ways of living create new problems and subsequently new opportunities for making use of insects. Rescue work in cities, for example in a collapsed building, presents particular challenges. Saint Bernard dogs with casks beneath their chins can’t help us here. In the modern-day urban environment your guardian angel may soon turn out to be a cockroach.
You’ve probably heard the saying that cockroaches are the only things that will survive a nuclear war. It’s a myth spawned by old films with thrilling titles such as Them, Bug, or Twilight of the Cockroaches; films dominated by postapocalyptic monster insects that eat atomic fallout for breakfast and any surviving women—preferably young beauties—for dessert. It’s nonsense, of course, although it is true that cockroaches can withstand more radioactivity than us humans (by the way, mealworm beetles can withstand even more).
Cockroaches’ resilience, not to mention their robust physique and spectacular motor skills, can actually be useful to us. Pack a tiny cockroach backpack full of modern technology: a microchip, a transmitter and receiver, and a control unit that is connected to the cockroach’s antennae and cerci, the tactile, taillike appendages on its rear end. The microcontroller, which is operated remotely, can stimulate the cerci with small electric impulses. This makes the cockroach think that something is approaching it from behind, so it runs away. If you send an impulse to an antenna, the cockroach thinks it has touched something and nimbly turns aside. In this way, you can remotely steer a whole armada of backpack-bearing cockroaches through a dangerous building and, by interpreting the signals that are sent back, can draw a map of the accident site.
The backpack can also be supplemented with a microphone that captures audio in the surrounding areas. In this way, the people remotely controlling the cockroach can listen for sounds from people who are trapped, after an earthquake, say. By steering the cockroach toward the sound, they can identify the position and come to the rescue more speedily.
So if you should be unlucky enough to get trapped in a collapsed building, don’t be too quick to stamp on any cockroaches that happen to come your way. They may prove to be your salvation. If, on the other hand, you should get lost in the Swiss Alps on a winter’s day, you’d be better off pinning your hopes on a Saint Bernard. Snowy weather is one of the few things a cockroach can’t deal with.
Every minute enough plastic is dumped into the world’s oceans to fill an entire dump truck. At least as much again ends up in landfill sites, and the amounts are constantly increasing. Because we love plastic. It’s handy and cheap. We produce and use twenty times as much plastic every year now as we did fifty years ago, and less than 10 percent of it is recycled. The rest of the plastic waste ends up in landfills, in roadside ditches, or in the sea. A report issued by the Ellen MacArthur Foundation estimated that if this continues the sea will contain more plastic than fish by 2050. This is because plastic biodegrades extremely slowly in the natural environment. So the discovery that a number of insects can digest and break down plastic is something of a sensation.
Take polystyrene, for example. Even if you don’t think you use it often, I’m guessing that you’ve held some in your hand—if you’ve ever bought takeout food in a carton or a hot drink in anything other than a paper cup. Because polystyrene, also known as isopore, is the material used to make disposable containers for hot food and drink. In the United States alone, 2.5 billion such cups are thrown away every year—and we’re talking about a material that was thought to be nonbiodegradable. Until now. Because it turns out that mealworms consume isopore cups as if they were part of their regular diet.
In one study, several hundred American and Chinese mealworms were served some isopore. All of them belonged to the darkling beetle species (Tenebrio molitor), which lives outdoors in most parts of the world and sometimes turns up indoors, too, if any soggy flour residue is left lying in your cupboards for too long. They gobbled up the isopore at record speed, and the larvae raised on this peculiar diet pupated and hatched into adult beetles as normal. Within a month, for example, five hundred Chinese mealworms had gobbled up a third of the 5.8 grams of isopore served up to them. All that was left was some carbon dioxide and a spot of beetle poo, which was apparently pure enough to use as planting soil. There was no difference between the survival rates of larvae that received normal food and those on the isopore diet.
But this can hardly be called a superfood. So another experiment compared three different groups: larvae that received isopore, larvae that received some kind of cornflakes, and larvae that received no food at all. The weight of the cornflake-fed larvae increased by 36 percent, while the isopore-fed larvae didn’t put on any weight. But they still did better than the poor starving larvae, who lost a quarter of their weight over the two-week duration of the experiment.
Strictly speaking, the beetles themselves aren’t the ones doing the job of breaking down the plastic. For this they rely on some tenants in their gut. If the mealworms are given antibiotics that kill off this gut flora, their ability to break down plastic also vanishes. The breakdown of plastic probably depends on the combined efforts of beetle and bacteria.
More research needs to be done into whether this insect can help us solve the problem of plastic in the oceans because mealworm beetles aren’t keen on getting their feet wet and are hardly suited to the seagoing life. But there is plenty of plastic on dry land that we’d love to get rid of, too, and these beetles may be able to help.
Mealworms are not alone. Other insects can also help solve the plastic problem. The greater wax moth is a lepidopteran that is viewed as a pest by beekeepers because it eats the wax combs inside beehives. But beeswax has a structure similar to that of polyethylene, which is the kind of plastic used in supermarket shopping bags. And sure enough, it turns out that the wax moth can eat holes in this kind of plastic and transform it into ethylene glycol, a substance we know as antifreeze. Again, this task is not performed by the larva alone but is probably a result of bacteria living inside its gut.
Researchers are now poring over these findings to discover how we can mass-produce the active substances and perhaps, over the long term, translate this into a practical solution to help us deal with our plastic waste.
Sometimes scientific discoveries come about quite by chance—as when a US scientist happened to forget some larvae in a drawer around the end of the First World War. It’s probably easy to get into a muddle when, like that chap, you’re studying everything from human cell structures and causes of sterility in mules to the caddis fly’s reaction to light. But quite why that scientist happened to leave a can of beetle larvae in his office drawer in the first place is a mystery.
At any rate, the point is not that he left them there but that he forgot about them. Totally and absolutely—for five whole months. And for the colored cabinet beetle Trogoderma glabrum, whose normal life cycle is a mere two months from egg to dead adult, five months without food should have been the end. But when the scientist finally rediscovered the larvae in his drawer, he found them in the best of health. Stranger still, they had grown younger! Yes, they really had!
If you cast your mind back to chapter 1, with its crash course in insect lore, you may remember that all insects shed their skin a number of times en route to adulthood. This is normally meant to go one way and one way only: from tiny larva to larger and more developed larva—just as we humans can go only from baby to teenager and not the reverse. But the larvae in the drawer had, in fact, gone the opposite way: they had developed backward, from big to little, from an advanced to a simpler larval stage.
This was revolutionary stuff. The scientist grasped that much. He continued to starve the beetle larvae and discovered that the insects could stay alive for more than five years “without a particle to eat,” as he wrote. They simply got smaller and smaller because they were living their lives backward—going from the late larval stages to the earliest. Stranger yet, when those poor wretches on enforced hunger strike were given access to food once more, the switch flipped back to normal mode and the development from “baby” to “youth” resumed.
A more recent study from the 1970s confirms those old findings. The larvae of the Trogoderma glabrum can develop forward and backward repeatedly. True, the process isn’t entirely without cost, because although it may look like a “baby larva,” a larva that has undergone repeated back-and-forth cycles will display physiological deterioration, indicating that it has aged after all. With each new round, it takes longer for the larva to grow bigger again.
It’s a pretty wild business. And there’s more where that comes from: the aging process can also be controlled in honeybees. Bees that are responsible for looking after the young in the hive can live and remain at the height of their mental powers for many weeks. However, worker bees, the ones that go out and gather nectar, die, thoroughly senile, after a couple of weeks. The ingenious thing is that if worker bees are forced to take on the hive bees’ job again, some of them actually “grow younger”—they have a longer life with high mental capacity. In honeybees, this is controlled by a special protein, a kind of bee elixir of youth. Studies of these insects can help us understand aging processes in humans, too, which may lead to new insights in areas such as dementia-related diseases, ultimately helping us achieve better health in our old age.
Speaking of life expectancy and aging, how about a trick that could help us with interstellar travel? Perhaps insects can help there, too. A nonbiting midge known as the sleeping chironomid, Polypedilum vanderplanki, is actually a hard-core aspiring astronaut equipped for prolonged periods of sleep.
The midge lives in Africa, and the larvae spends their life in small puddles of water that are constantly drying out. But whereas we humans die if we lose more than 14 percent of the water in our bodies and most other organisms can withstand a maximum water loss of 50 percent, this chironomid can cope with a loss of up to 97 percent! In this desiccated state, the larvae can handle pretty much any pummeling: you can boil them, dip them into liquid nitrogen, soak them in alcohol, expose them to cosmic radiation for years, or simply leave them alone; the record survival time to date is seventeen years.
When it is time for them to wake up, all you have to do is pour water on them, and—Hey, presto!—like the freeze-dried chunks of meat in packages of dehydrated soup, the larvae swell up to their normal size. Give them an hour, and they will be busy eating again as if nothing had happened.
So the midge larva can enter into a state that is somewhere between life and death without suffering any apparent harm. All it needs is a little time to prepare itself. The key to its survival seems to be for it to replace the water in its body with a kind of sugar called trehalose. This sugar is only about half as sweet as normal sugar and occurs naturally in small concentrations in insect blood. Incidentally, trehalose is named after the cocoon-shaped larval secretions of a true weevil (or snout beetle) found in Iran, which is known as trehala in Persian and is widely used in Persian traditional medicine.
When the larva realizes that tough times lie ahead, its body begins to produce more trehalose sugar, which rises from the normal level of around 1 percent of its blood up to around 20 percent. The sugar protects the cells and bodily functions in various ways.
Several other organisms have mastered the art of becoming the living dead, including bacteria, fungi (think of dried yeast!), roundworms, tardigrades, and springtails. The exciting thing is that they don’t all use the same techniques. In tardigrades, for example, there is no sign of trehalose accumulation.
If we can get to the bottom of the processes that control this switch between normal life and desiccated dormancy, we can use it to keep cells, tissue, or perhaps even individuals in a desiccated state. Perhaps an African midge will help us find the key to interstellar travel in the future!
While we wait for insects to help us travel to the stars, how about getting them to help us travel among the flowers? That way, they can pollinate plants for us along the way. Robot bees actually do exist, in laboratories at any rate: tiny drones that have been enhanced with a brush and electrically charged gel so that they can gather pollen. Carbon-fiber brushes, nylon hair from a makeup brush (yes, really), and horsehair have all been tested, and although horses aren’t known for their pollinating skills, the horsehair brush worked best. With that, robot bee 1.0 was ready for testing. You can find a video clip on the internet of the drone flying from lily to lily in the Japanese laboratory where it was created. The flight itself is rather clumsy, but then again, drone flying isn’t on the university curriculum—yet.
The most obvious area of application for these sorts of drones is on pollination-dependent food crops in greenhouses. That might allow us to restrict the use of introduced bumblebee species, which have a habit of escaping from the greenhouses and dispersing in the natural world. For now, the robot bees aren’t especially efficient because they have to be controlled manually and need constant recharging, but perhaps in the future they will be able to navigate using GPS or be controlled by artificial intelligence and will have batteries with a longer life.
Let’s hope we don’t end up in a world in which we believe modern mechanics can replace nature’s infinitely advanced functions. In nature, more than 20,000 different species contribute to the pollination of wildflowers and crops, and research shows that pollination is most effective when it involves a diverse range of species with different special adaptations. We know that the interplay between insects and flowers has been fine tuned over more than a hundred million years and that natural pollination is far more complex and ingenious than any imitation we might come up with. It is simply easier and cheaper to conserve the solutions that nature gives us free of charge.
When it comes to gaining new insights from old insects, we never know which species will turn out to be useful next. Mealworms, fruit flies, or cockroaches; ants or midges. We humans are quick to categorize other species according to whether they are a help or hindrance to us. And we’re generally anxious to get rid of the ones that fall into the latter group. But nature is so cleverly organized that, with better knowledge, we will always be discovering new smart solutions. This is one reason it is so important to conserve the natural world and all the species that live in it, whether we consider them useful or not.