We have named one million types of insect but think there are four million more. The world is populated, primarily, by these small and often irritating beasts. Ants alone outnumber us by a million to one and the weight of ants in the world is greater than the weight of humans.

Best of all, insects are bewilderingly, heart-liftingly crazy. The bombardier beetle crawls around with a bottom full of chemicals that can react explosively and destroy predators. A type of termite does something similar, but in an act of suicidal altruism it blows itself up in the process.

There are earwigs with two penises — if threatened during copulation they can let the active one break off. There’s the emerald cockroach wasp, which uses brain surgery to turn off its victim’s escape reflex. Dung beetles navigate by aligning their movements by the dim light of the Milky Way. Mayflies time their brief lives by the light of the full moon. The caterpillar of the elephant hawk moth deters predators by disguising itself as a rearing snake.

“Would the world,” Dave Goulson, author of the upcoming book Silent Earth, asks, “not be less rich, less surprising, less wonderful, if these peculiar creatures did not exist?” Indeed it would.

Pulling Their Weight

We spend our time speculating about aliens from other planets, but we’re surrounded by creatures strange beyond our wildest imaginings. Yet they are not just there to amaze or, often, irritate. The truth about these six-legged weirdos is we cannot live without them.

Small as they are — and some of them are microscopic — they do much of the essential heavy lifting of planetary care. They pollinate, break down waste and provide food for us and for countless other species. If they vanished tomorrow the apocalypse would begin the next day.

There are thousands of butterfly species, including the blue tiger, and there used to be a lot more. Today, butterfly numbers are plummeting.

And yet, being dumb destructive humans, we are massacring them on a scale that defies belief. The overall biomass — weight — of insects fell 75 percent between 1989 and 2016. In the rain forests it is estimated that 135 species go extinct every day, most of them insects. They are on the front line of nature’s defense against the human assault on the biosphere.

If you’re over a certain age you can see the effects of this slaughter. The windscreen of your car is now spattered with fewer and fewer bugs. The lovely great yellow bumblebee is extinct in England and Wales and now only clings on in the north and west of Scotland. Most heartbreaking of all, butterfly numbers are plummeting — no more clouds of brilliant color rising from hedgerows and meadows.

Small as they are, they do much of the essential heavy lifting of planetary care. If they vanished tomorrow the apocalypse would begin the next day.

Goulson is a biologist with an inordinate fondness for insects. For him they are our “brethren”. This book is his attempt to educate us in their eccentric beauty and their absolute necessity.

He asks us to step away from our anthropocentric vanity, our tendency to see nature as nothing but a source of food, leisure, health and spiritual improvement. We talk of protecting it because without it we would perish. Yet we should accept the truth that Nature has values of her own, independent of us.

“One can argue,” Goulson tentatively suggests, “that all of the organisms on Earth have as much right to be here as we do.”

A honeybee takes flight.

We are killing the insects in the same way we are killing countless other species. There are too many of us and we’re doing all the wrong things — poisoning the land, chucking carbon into the atmosphere, destroying habitats, throwing away valuable topsoil at the rate of 100 billion tons a year, chopping down rain forests and eating too much, especially meat. “We are,” Goulson writes, “committing ecocide on a biblical scale.”

And, fruitless virtue signaling aside, we don’t seem to care. Or rather we pretend we do. In 1992 at the Rio Convention on Biodiversity 196 governments solemnly agreed to stop global biodiversity loss by 2020. What followed was “the greatest loss of global biodiversity for at least 65 million years”.

“We are committing ecocide on a biblical scale.”

We blunder on in ignorance. Goulson takes his students at the University of Sussex on walks around the campus to see how much they know about nature. Half of them can identify blackbirds or robins, but no other birds. Almost none can identify common trees such as oak or ash. And these are ecology students.

So, first, educate; then, do not “rely on the empty promises of our governments to save our planet”. They never deliver. We need to act alone. Like many such books, Goulson’s ends with a list of “actions for everyone”, but his is much longer than most, more specific and insectcentric. For example: “French marigolds seem to help deter whitefly from tomatoes and borage attracts pollinators to strawberries.”

Crucially, avoid chemicals. You won’t ever touch the herbicide glyphosate — Roundup as it is commonly known — after reading this book. The science is all contested, but two US courts were persuaded that it causes non-Hodgkin’s lymphoma in humans. They awarded victims $289 million and $80 million in damages.

Yet, in the end, the best advice is to do what Goulson does — look and wonder. Take the bumblebee, his particular favorite among insects. You may, if you are a looker, have been puzzled by the way they alight on particular flowers. The reason is they can tell whether any flower has been visited by another insect. Either they can smell the feet of previous nectar-suckers or — pause a moment here — they can detect a change in the electrostatic field caused by a recent visit.

Insects are the most vivid expressions of the astounding fact of life in what may be a dead universe. Read this book, then look and wonder.

Dave Goulson’s Silent Earth: Averting the Insect Apocalypse will be available in September

Bryan Appleyard is a British journalist and the author of several books, including How to Live Forever or Die Trying