Back Forty: Food crops depend on an army of insects. Now, they’re disappearing

In his book, “The Insect Crisis: The Fall of the Tiny Empires That Run The World,” Oliver Milman opens with a deafening silence. Cicadas have vanished, and so have crickets. Without the low hum of bees and mosquitos, gardens and parks become “lifeless imitations of themselves.” Birds, squirrels, and hedgehogs die en masse. Then the global food system collapses. Renowned entomologist E.O. Wilson once said that humanity would only last a few months without insects, an idea that Milman dissects in his book’s prologue. “You don’t really know what you’ve lost until it’s gone,” he told FERN.

Insects make up three out of every four known animal species, and recent studies suggest they’re disappearing: humans are decimating their habitats, upending their food supply, and poisoning them with agricultural insecticides. In his urgent and rattling new book, Milman – an environmental reporter at The Guardian – explores the damage we’ve done to the insect populations we rely on and what we can do to help them recover. FERN sat down with him recently for an interview, which has been edited for length and clarity.

So the prologue of your book definitely kept me up last night. In this apocalyptic, worst-case scenario, you describe a world without chocolate covered in a “tsunami of feces.” How is this future connected to insects?

Insects pollinate a third of the food we eat. Without them, you would be without melons, broccoli, cherries, almonds—all the bright, colorful stuff on our plates. We tend to think about bees and their usefulness, but I think it’s less well known that other insects do a lot of pollination, like flies. Within the fly family, you have little tiny midges. They fly into the cacao plant, get into this tiny opening and pollinate it. Essentially, the $100 billion-a-year chocolate industry rests upon the tiny, slender shoulders of this little midge. There’s no replacement for it. So unless you want [a future with] hundred dollar chocolate bars, the little midge is your hero.

Now, the feces: insects do a lot of unglamorous things in our world, and decomposition is kind of top of that list. So you’ve got feces and dead bodies being broken down by flies and beetles before bacteria get in there. And obviously without that you would be left in a much messier, yuckier kind of place. I was struck by this example of what happened in Australia in the 19th century when Europeans brought cattle there. They ended up with the whole continent of Australia caked in shit, because they didn’t have a native insect that could break down the manure.

Where exactly are we in this kind of mass insane insect extinction? Are we at a point of no return?

I don’t think we have the full picture yet, partly because we don’t even have the full picture of all the insects out there. I mean, there are 1 million named insect species, but by some estimates, there could be up to 30 million species out there. So I think it’s important to understand that we don’t know exactly what the trends are in every single country in the world. What we do have are some very alarming glimpses into these incredible declines.

One of the studies that really caught my eye was a big German study in 2017, where this entomological group tracked data from 63 nature preserves across Germany going back to 1989. From that period up to the publication of their paper in 2017, they found a 76-percent decline in the average weight of the flying insects they caught each year in their traps. In the summers, when insects are meant to be at their peak, they found the insect population declined 82 percent. From the time the Berlin Wall came down to now, Germany’s lost three quarters of its insects. These are amazing declines—and you see them all over the place. So we are in a very worrying place.

Let’s talk about why this is happening. Your book examines a number of ways in which humanity wreaks havoc on insect populations, but can you talk about agriculture, and specifically monoculture?

I mean, I think the key to a lot of ecological function is diversity. You need a diversity of landscapes and plant species for things to function properly. And the problem with monocultural farming practices is that focusing on just one or two crops for financial reasons has come at the expense of that diversity—and insects have suffered along with other creatures because of it. As one researcher said to me, ‘We’ve offered them chips, nothing but chips—even if you don’t like chips, or are allergic to chips, all you’ve got to eat are chips.’ So, if you’re a bee and all you’re being offered is a plain field of corn or soy, it’s a desert, essentially. And now they [also] don’t have the habitats they once had, the grasslands, the wildflower meadows, the forests—we’ve chopped down a third of all the world’s forest since the dawn of the industrial era.

You also devote a decent chunk of the book to pesticides, and you particularly focus on neonicotinoids. One of the most disturbing stories in the book was your description of their impact on honey bees in California’s Central Valley—you connect these insecticides to mass die-offs and colony collapse disorder.

Yeah, I spoke to a beekeeper who this happened to, and he was flabbergasted to find there were just no bees in his hive one day. And this was a phenomenon that was then recounted by beekeepers around the world. Today, the best guess is that neonicotinoids are to blame. They’re a class of insecticides that are used widely across the U.S.

Researchers have been looking at the impact of “neonics,” as these insecticides are known, and it turns out they scramble bees’ brains. They mess with their logistical functions, their memories; they don’t come back to the hive, because they don’t remember where it is. And it kills them in huge numbers, along with butterflies and beetles and everything else that gets in the way. They [neonics] are also water soluble, unlike other pesticides, so that means as soon as it rains, they wash into soils and waterways and affect a whole range of wildlife.

And you write that neonics are 7,000 times more toxic than DDT. That was remarkable to read!

Yeah, U.S. agriculture has become 48 times more toxic than it was 25 years ago. It’s an extremely perilous environment for a lot of insects to live in.

A third cause of the insect crisis is, of course, climate change—and at risk of sounding like a total rube, I was a bit surprised by just how damaging it was, since many insects seem to flourish in hot or tropical climates.

I think climate change is an interesting one—it’s really hammering insects far more than I think scientists originally thought it would, and it’s creating winners and losers. Mosquitoes really like warmer temperatures, for instance. By one estimate, a billion extra people are going to be exposed to mosquitos carrying disease due to climate change. So mosquitoes are winners in this scenario. Bumblebees, less so. Bumblebees are kind of sewn into these little sweaters at all times, and so when it heats up for them, their situation gets worse. I think a quarter of all bumblebee species in North America are declining and climate change is cited as a major contributor towards that.

Let’s talk about solutions. Are there ways to avert this crisis that really stand out to you? Agricultural strategies that can at least slow this extinction crisis down, if not stop it?

Yeah, I think one of the encouraging things about this is it’s not completely hopeless yet. We don’t need to invent a new vaccine or win a space race. We know what we can do here, and there are some places moving towards the right models.

If you look at the European Union, for example, they’ve banned three of the worst neonicotinoids for agricultural use. You can also pay farmers, like the EU has, to plant wildflowers through fields so there are wildlife corridors through agricultural areas and it’s not a complete desert. And there’s work that we all need to do on climate change. If you have a yard, you can give insects a break by not worrying about your lawn as much, not raking leaves, not putting chemicals everywhere, and thinking about a range of different native plants that native pollinators would enjoy.

They are the great survivors after all. They predated and then outlived the dinosaurs, they’ve gone through five mass extinctions. They can adapt. We just need to give them the space in which to do that.

CORRECTION: An earlier version misstated the toxicity of neonicotinoids in relation to DDT.