eBook - ePub
The Insect Crisis
The Fall of the Tiny Empires that Run the World
Oliver Milman
This is a test
Share book
- English
- ePUB (mobile friendly)
- Available on iOS & Android
eBook - ePub
The Insect Crisis
The Fall of the Tiny Empires that Run the World
Oliver Milman
Book details
Book preview
Table of contents
Citations
About This Book
***A Waterstones Best Books of 2022 pick*** A New Scientist Book of the Year Shortlisted for the Wainwright Prize for Conservation Writing 'Fascinating... There is something wondrous in Milman's revelation of our fragile dependency on insect life as well as its beauty and strangeness.' Guardian 'Gripping and especially unnerving.' David Wallace-Wells When is the last time you were stung by a wasp? Or were followed by a cloud of midges? Or saw a butterfly? All these normal occurrences are becoming much rarer. A groundswell of research suggests insect numbers are in serious decline all over the world - in some places by over 90%. The Insect Crisis explores this hidden emergency, arguing that its consequences could even rival climate change. We rely on insect pollination for the bulk of our agriculture, they are a prime food source for birds and fish, and they are a key strut holding up life on Earth, especially our own. In a compelling and entertaining investigation spanning the globe, Milman speaks to the scientists and entomologists studying this catastrophe and asks why these extraordinary creatures are disappearing. Part warning, part celebration of the incredible variety of insects, this book highlights why we need to wake up to this impending environmental disaster.
Frequently asked questions
How do I cancel my subscription?
Can/how do I download books?
At the moment all of our mobile-responsive ePub books are available to download via the app. Most of our PDFs are also available to download and we're working on making the final remaining ones downloadable now. Learn more here.
What is the difference between the pricing plans?
Both plans give you full access to the library and all of Perlego’s features. The only differences are the price and subscription period: With the annual plan you’ll save around 30% compared to 12 months on the monthly plan.
What is Perlego?
We are an online textbook subscription service, where you can get access to an entire online library for less than the price of a single book per month. With over 1 million books across 1000+ topics, we’ve got you covered! Learn more here.
Do you support text-to-speech?
Look out for the read-aloud symbol on your next book to see if you can listen to it. The read-aloud tool reads text aloud for you, highlighting the text as it is being read. You can pause it, speed it up and slow it down. Learn more here.
Is The Insect Crisis an online PDF/ePUB?
Yes, you can access The Insect Crisis by Oliver Milman in PDF and/or ePUB format, as well as other popular books in Sciences biologiques & Réchauffement climatique et changement climatique. We have over one million books available in our catalogue for you to explore.
Information
1
An Intricate Dance
The question of how long human civilization would withstand the loss of insects is both hideous and unfathomable. Hideous because the collapse of arable farming and ecosystems could wipe us out within just a few squalid months, the biologist E. O. Wilson has predicted. Most of the fishes, mammals, birds, and amphibians would plunge into oblivion before us, followed by flowering plants. Fungi, after an initial explosion from the death and rot, would also die off. “Within a few decades the world would return to the state of a billion years ago, composed primarily of bacteria, algae and a few very simple multicellular plants,” Wilson wrote.
And yet, unfathomable. Such a dire scenario can barely be comprehended given the stubborn survival of insects through the five mass extinctions that have roiled Earth in the past 400 million years. Humans have never existed without them, so have never had to properly consider their absence or even diminishment.
But a torrent of recent findings have pointed to major declines in the abundance and species diversity of insects in places around the world. Seemingly without cause they are crashing, their numbers thinning out at astonishing rates at different research sites—in some places by half, others by three-quarters, and in one, in the seemingly benign countryside of Denmark, as cataclysmic as 97 percent. The mounting evidence of plummeting insect populations forces us, for the first time in our history, to grasp the wretched consequences of their decline. This book will explore the unfolding crisis in the insect world, what’s causing it, and what can be done to stem the loss of the miniature empires that hold life aloft on our raucous, plastic-strewn, beautiful planet.
In a bewilderingly rapid reimagining of our world, what was once infinite now seems jarringly vulnerable. Without insects, the world’s wealthy could perhaps deploy the resources required to indefinitely stretch out a semblance of the status quo. But for the majority of humanity, the loss of insects would be an agonizing ordeal eclipsing any war and even rivaling the looming ravages of climate breakdown. “Most of life on Earth would disappear if we didn’t have insects, and if there were any humans left they wouldn’t be having much fun,” says Dave Goulson, professor of biology at the University of Sussex. “I think it is stretching it a bit to suppose that all humans would be dead in a few months, but there is no doubt that millions of us would be starving.”
Insects have been involved in an intricate dance with almost every aspect of the terrestrial environment for millions of years, forming an underappreciated foundation for human civilization itself. They multiply our food, act as food themselves for the other living creatures around us, rid us of the foulest waste, eliminate unwanted pests, and, crucially, nourish the soil, the 15-centimeter (6-inch) patina wrapped around our globe that sustains all of humanity. Rachel Warren, a professor of environmental biology at the University of East Anglia, compares our deeply woven reliance on insects to the internet. “In an ecosystem everything is connected by this net of interactions,” she says. “Every time you lose a species you’re cutting some of those links in this network. The more links you cut in the network the less of this internet there is left, until eventually it doesn’t work anymore.”
Without a pollinator, a plant dies and isn’t replaced. The birds that feasted on the plant’s fruits or the deer that browsed on its buds start to dwindle, followed by the animals that feed upon them. “The whole food web just disintegrates,” Warren says. “I don’t think humans could survive in that world at all.”
The weight of this dependence has failed to spark much devotion for insects. Three out of every four known animal species on Earth are insects and yet, within their massed ranks, only butterflies are considered with anything close to affection. Wasps are a baleful summertime menace, ants an invading army fought with toxic sprays in the kitchen, and mosquitoes everything from irritating nuisance to lethal threat. Most of the other 1 million species of identified insects are considered by many people, if they are ever considered at all, to be either quirkily obscure or pointless.
There are around 7,530 types of assassin fly, a creature that spends its short life spearing other insects with a sturdy proboscis in order to paralyze them and liquefy their internal organs. This horde alone comprises more species than mustered by the entire world of mammals—apes, elephants, dogs, cats, domestic cattle, whales, the lot. A botfly called Cephalopina titillator matures in the nostrils of infested camels, just one specialist among 150 species of botflies, while there are at least half a million species of parasitoid wasp, creatures so detested by Charles Darwin that he wrote in a letter, “I cannot persuade myself that a beneficent and omnipotent God” would’ve created them. What would really be lost if these abhorred wasps and flies, maybe all flies in general, just vanished?
“You get rid of flies? You get rid of chocolate,” says Erica McAlister, a senior curator at the Natural History Museum, London, and an avowed defender of flies who once took part in an entomologist gokart event dressed as one. Appropriately, she successfully chased down a colleague who was dressed as feces. “Flies are really important pollinators when it comes to carrots, peppers, onions, mangoes and a lot of fruit trees. And chocolate. They work longer hours than bees and don’t mind the cold as much. We’re beginning to finally take notice of all this.” There are approximately 160,000 species of Diptera—an order more commonly called true flies or two-winged flies—which includes houseflies, midges, mosquitoes, and fruit flies. The number of fly species is at least four times larger than all the different types of fish found in the world’s oceans. This diverse group perhaps deserves to be viewed as a collection of finely tuned environmental engineers rather than as annoying pests that circle overhead or speckle browning bananas in fruit bowls.
Tiny midges, each the size of a pinhead, crawl into the tiny flowers of cacao plants across Africa and South America and keep the world’s $100 billion chocolate industry from collapse. Thousands of different blowflies, flesh flies, and soldier flies dispose of dead animals, rotting leaves, and feces—for free. Scientists have harnessed maggots for the treatment of gangrenous wounds without antibiotics, while oil has been extracted from the larvae of black soldier flies and turned into a form of biodiesel to run cars and trucks. “They’re doing such wonderful jobs, all sorts of things that we just don’t realize,” says McAlister. “Can you imagine if they didn’t? You’d be swimming along in a quagmire of feces with Uncle Jeremy floating past you.”
Flies are recondite yet prodigious pollinators. Volucella zonaria, a hefty hoverfly with bumblebee-like black and yellow hoops on its abdomen, is “basically a flying tank,” according to McAlister. It is capable of buzz pollination, which means it can grip onto petals and violently vibrate, releasing pollen that is stubbornly lodged in the anthers of a plant. Few bees are able to do this, meaning without flies there would be no cornucopia of tomatoes and blueberries available for us to feast upon.
Some plants are completely dependent on certain flies. One extraordinary creature, Moegistorhynchus longirostris, is found on the west coast of South Africa. It has a nonretractable proboscis that measures up to 7 centimeters (almost 3 inches) long, several times its own body length, making for an awkward flailing appendage when flying. It flits around plants that have developed tubed flowers that perfectly fit the fly’s lengthy probe, further highlighting an evolutionary theory posed by Darwin after he was sent some orchids from Madagascar in 1862 that stored nectar in exceptionally long necks. Darwin suggested that a moth with an absurdly long tongue must have evolved alongside this plant—a species that was only discovered decades after the evolutionary theorist’s death. “If just that fly in South Africa disappeared, eight plant species would die out immediately,” says McAlister. “Flies have got a huge history with pollination that has been wildly ignored.”
Even on their own terms, flies can fascinate—some species present edible gifts to potential mates, while others perform intricate dances. To some people, flies could even be considered beautiful. Michelle Trautwein experienced a pivotal moment as an art student when as part of a studio review she unveiled a vast biological illustration of a stone fly, an order of insects with elongated bodies, long antennae and two pairs of membranous wings. “The art professor hated it,” recalls Trautwein. The professor strongly preferred the work of a student who had smeared wet cat food across a blank white canvas. “I remember just thinking ‘That’s it. I’m out.’ ” Trautwein “just fell into flies” and is now a leading entomologist in her discipline at the California Academy of Sciences.
While stone flies are not typically gushed over as classically photogenic, there are flies that could lay claim to such adulation. The Lecomyia notha soldier fly, from Queensland, Australia, has an iridescent, opal-like exoskeleton, a shimmering blur of purple and blue. Another fly, with a bright, golden abdomen, has been named Plinthina beyonceae, after the singer Beyoncé. “Entomology is a really beautiful, aesthetically pleasing field,” says Trautwein. She was drawn to flies, and insects in general, because they resemble “aliens on Earth.”
“There’s millions and millions and millions of them, we don’t even know how many,” Trautwein says. “Each one is like an alien life form with a detailed life history that often is so bizarre, you couldn’t create it as fiction if you wanted to.” As dizzyingly diverse as insects are, they share a remarkably consistent body design comprising three segments—head, thorax, and abdomen—three pairs of jointed legs, compound eyes, antenna, and an external skeleton.
This structure provides the platform for feats that would cause widespread awe if performed by larger animals. The dracula ant can snap its mandibles at 322 kilometers (200 miles) per hour, the fastest animal movement on Earth. Their cousins, the African Matabele ants, have been seen carrying injured comrades back to the nest to tend to their wounds like six-legged paramedics. Some caterpillars generate their own antifreeze to ward off the cold. Honeybees understand the concept of zero and can add and subtract numbers. But these creatures—so numerous that they are both unknowable and annoying, so odd looking that they inspire the forms of malevolent beings in horror movies, and so vital that we would perish without them—now appear to be suffering a silent existential crisis.
The alarm over insect declines has been rung intermittently for some time, if not quite as loudly as now. As early as 1936, Edith Patch, the first female president of the Entomological Society of America, gave a speech decrying the expanding use of insecticides on fruit and vegetable crops. “Certainly too little popular emphasis has been given to the service of insects to mankind,” Patch said, adding that “too few do realize our dependence upon them for most of our food and clothing, a significant amount of our industry, and for much of our pleasure.” More presciently, “If [mankind’s] goal is a wholesale destruction of dangerous insects, his brains will provide the equipment for such a campaign in the course of time.”
In the decades since, humanity hasn’t consciously geared its collective brain to decimate all sorts of insects, much as it hasn’t deliberately decided to drown its coastal cities and fuel enormous wildfires through climate change. Nevertheless, that has been the result. Through the destruction of insects’ habitats, the spraying of toxic chemicals, and, increasingly, the heating up of the planet, we have unwittingly crafted a sort of hellscape for many insects, imperiling all we rely upon them for. “We are creating a world that is not only a problem for insects, but even for us, for humans,” says Pedro Cardoso, a biologist at the Finnish Museum of Natural History.
The exact dimensions of the insect crisis have long been obscured by a fog of logistical impossibilities. There are 1 million named insect species, but as insects are small, cryptic, and not extensively tracked, this is only a glimpse of what is undiscovered and unnamed: estimates vary from an eye-watering 30 million species to a more realistic 5.5 million. “Who knows what’s out there?” says Goulson. “Probably all sorts of weird and wonderful beasties.”
Taxonomists, the biologists who name species and work out where they fit into the larger puzzle of living things, face a Sisyphean job just to differentiate between seemingly identical species. To most of us, some ants are black and some cinnamon colored, some flies are big and some are small, but beyond that the distinctions end. Specialists have to spend a lot of their time gazing at insects’ reproductive organs to make their classifications. “We are genitalia fiddlers,” says McAlister, the fly expert. “We like nothing more than cutting open a fly and looking at its goolies.”
This painstaking work, combined with the fact that taxonomy is increasingly dismissed as a fusty natural history version of stamp collecting by students now more drawn to molecular biology, means that the job of describing all insect life on Earth will probably never have an end date. As McAlister puts it: “We’ve got 50,000 people studying one type of monkey and one person studying 50,000 types of flies.” For every fly successfully identified by its genitalia, science dumps many more potential candidates on the desk of taxonomists. In 2016, Canadian scientists completed a DNA analysis of more than 1 million insect specimens and were shocked to find that the country probably has around 94,000 insect species, nearly double the previous estimate. If Canada has 1 percent of the world’s insects, the researchers mused, the planet has around 10 million insect species.
Even with what is already described, it’s clear we live in an invertebrate’s world. Just 5 percent of all known animal species have a backbone. The globe is filled with not people or sheep or even rats, but beetles—350,000 species and counting. What we do know about overall insect populations doesn’t immediately spur thoughts of shortage, either. The Smithsonian Institution estimates there are around 10 quintillion (that’s a 10 with eighteen zeros following it) insects in the world. A locust swarm can contain 1 billion individuals. The southern portion of England alone hosts 3.5 trillion migrating flying insects a year, a mass of bodies weighing the equivalent of 20,000 flying reindeer.
If you got all the termites in the world and scrunched them into a giant ball, this seething clump, a measure known as biomass, would weigh more than all the birds on the planet. Before people started ballooning in both population and girth in our era of industrialized modernity, all the world’s ants probably weighed more than all the world’s humans, too. “Today’s human population is adrift in a sea of insects,” as a pair of Iowa State University scientists wrote in 2009. “Based solely on numbers and biomass, insects are the most successful animals on Earth.”
Insects are surprisingly hardy and adaptable, too. The Sahara desert ant can survive temperatures of up to 70°C (158°F), while, in the other extreme, the larvae of the Antarctic midge can cope with −15°C (5°F) and as long as a month without oxygen. Tiny ephydrid flies can live and breed in the hot springs of Yellowstone National Park that would fry a human. Bumblebees have been found at 5,500 meters (18,000 feet) above sea level, a height just shy of Mount Kilimanjaro’s summit. Dragonflies can steadily hover in fierce winds that would down even the most advanced helicopter. A horned dung beetle is so strong that if it were a human, it would be able to hold aloft six double-decker buses.
You could say that the insect family embraces the bizarre. Insects breathe in and out via holes called spiracles in their exoskeletons and see via intricate compound eyes, allowing creatures such as dragonflies to have a 360-degree field of vision. Stingless bees feed on human sweat and tears, a species of butterfly has an eye on its penis, and some aphids can produce young that already contain their own babies—effectively they give birth to their own grandchildren. Insect populations are normally fairly elastic, too, able to navigate huge spikes and troughs when dealing with changeable conditions. But while insects are legion, that doesn’t mean that they are utterly disposable—they all play some sort of role in pollination, or in decomposition, or in the food chain.
Start yanking enormous numbers of insects out from the environment and the whole web of life, including humanity, is thrown off-kilter. The collapse can fold in on itself, too—around 10 percent of insects are parasites, often of other insects. If certain wasps can’t find caterpillars to act as their slave puppets and egg hosts, or if certain flies can’t hijack an ant’s brain and then decapitate it, they, too, are under threat. This dangerous scenario is now coming i...