Bringing back the buzz with Dave Goulson

Entomologist Dave Goulson on vanishing insects, pesticide-laced bedrooms, and why the fate of bees and humans are more intertwined than we’d like to think.

Dave Goulson has spent his entire career studying insects and watching them disappear. Professor of biology at the University of Sussex, founder of the Bumblebee Conservation Trust, and author of more than a dozen books, his latest, Eat the Planet Well, published on the day of this recording, is a guide to eating sustainably that connects the food on our plates directly to the crisis unfolding beneath our feet. We spoke about the staggering scale of insect decline, the agrochemical industry’s grip on farming, and why your messy garden might just be a small act of resistance.

The first thing you need to know about Dave Goulson is that his love of insects is not something he can explain rationally. It began at primary school, collecting caterpillars from the edge of the playing field and bringing them home in an empty lunchbox to keep in jam jars on his bedroom windowsill. Most of them died, he admits, but some survived, including a set of tiny yellow and black striped caterpillars that became cinnabar moths, brilliant red and black. “I just thought that was really cool,” he says, with the tone of someone who still thinks it’s really cool, four decades later.

It’s a disarming quality, that unguarded enthusiasm, in someone who also has to regularly deliver some of the bleakest statistics in contemporary science.

The scale of what we’ve lost is difficult to comprehend. Where do we actually stand?

All the evidence we have suggests insects have undergone a pretty massive decline, and that it’s still ongoing. It’s quite hard to put accurate figures to it because the data we have are really patchy. We don’t have a global insect monitoring network, which would be ideal. We only really started monitoring any insects in the 1970s, which was probably long after they started declining. But a reasonable estimate is that in Europe we may have lost 90% of our insects in terms of abundance over the last hundred years. We can’t be entirely sure of that figure, but that’s where the evidence points.

The causes are numerous. The biggest one is habitat loss driven by the industrialisation of farming, and associated with that, all the chemical inputs, particularly insecticides, which are designed to kill insects, so it’s not really surprising that they’re driving insect declines. Then there are invasive species, like the yellow-legged hornet from Asia, which is sweeping through Europe and decimating wild bee populations. Climate change is starting to kick in. Light pollution affects nocturnal insects. It’s a perfect storm of problems, all of them manmade, that insects have to deal with.

It’s worth pointing out: insects are pretty tough. They’ve been around for nearly half a billion years, twice as old as the oldest dinosaurs. They survived mass extinction events, including the meteor that wiped out the dinosaurs. So it’s quite telling that after all of that, they’re now struggling because of us, in the blink of an eye, really, in the last hundred years.

You live in a rural part of southeast England, exactly the kind of place you’d expect to be full of wildlife. What do you actually see when you step outside?

There are still butterflies and birds and some wildflowers, but there’s an awful lot of bugger all, to be honest. Even ten years ago I remember hearing skylarks singing. There aren’t any skylarks anymore. Cuckoos, occasionally in the spring. I don’t hear those either. Both feed at least partly on insects. That’s one of the many knock-on effects of declining insect populations: things that rely on them for food are obviously also declining. It’s a bit disheartening at times.

For someone who lives in a city, it’s possible to go through life and genuinely not notice any of this. How do you explain why it matters?

We’ve become an urban creature, and it’s really easy for people to be completely disconnected from nature, not realising that we are still part of nature, that we all depend on food, which has to be grown in a healthy ecosystem. It needs soil, it needs pollinators, it needs insects to recycle.

There’s a whole list of things insects do that we can’t do without. Lots of creatures eat them, creatures that people value, like birds. Most bird species, plus bats, fish like salmon and trout, most amphibians and reptiles, they all depend on insects for food. Beyond that, insects control crop pests, recycle dung and dead matter to release nutrients for new growth, and help keep soil healthy. And then there’s pollination, which has at least seeped into public consciousness. People know, roughly, that bees pollinate plants and without them we’d have less fruit and veg. That’s broadly true. Three-quarters of the crops we grow wouldn’t give a full harvest without being visited by some kind of insect.

Though often it’s not a bee. It might be a butterfly, a moth, a hoverfly, a wasp, a beetle. There are thousands of species of insect that pollinate. A nice example is cacao, which gives us chocolate, pollinated by tiny little midges, the only things that can get through the small entrance of the flower. Bees can’t get in at all. So for chocolate, at least, bees are entirely irrelevant. No midges, no chocolate: that’s probably a better marketing campaign than most things I’ve heard.

Your new book, Eat the Planet Well, might seem like a departure for someone known for studying bees. What’s the connection?

It’s become pretty clear to me that our fate and that of insects are intertwined. A lot of the things driving insect declines are also affecting us. Pesticides affect bees, but they’re also in our food, and there’s clear evidence that human exposure to pesticides is harmful to health. And broadly, I think the industrialisation of agriculture is not sustainable. It’s the biggest driver of biodiversity loss. One recent estimate suggests 40% of the world’s soils are now badly degraded. Food growing, processing and transport is a massive contributor to climate change.

The system we have can’t carry on. The planet can’t cope, especially with a growing human population. We need to ask: how do we come up with a better system that actually feeds eight billion, soon probably ten billion, a healthy diet without destroying the planet? If we can answer that, then we can save the bees and everything else. It’s all intertwined.

We often talk about the Green Revolution as a mistake, but at the time it was a genuine solution to a real problem.

I completely agree. It’s easy to see why we adopted these practices. There was a time when people were hungry, when food was rationed across much of Europe. Producing more food obviously seemed like a good idea. But the way we’ve done it, we’ve done too much. The irony is it’s been so successful that we now massively overproduce crops and have become incredibly wasteful. Roughly a third of all food grown is wasted. And we do far too much animal farming. Something like 77% of all the world’s farmland is devoted to producing meat, which provides about 18% of our calories. The logic just isn’t there.

If you’d started from scratch to devise a way to feed eight billion people efficiently and healthily, you would definitely not have arrived at the system we have today.

A lot of that system is held in very few hands.

It’s all wrapped up by a very small number of companies these days. There have been various buyouts and mergers. I think there are a couple more in Asia, but yes, it’s Bayer, Syngenta, Corteva, a tiny number of players who between them control the fertilisers, the pesticides, the GM crops, the seed patents, and increasingly the curricula in agricultural universities as well. They’ve tied farmers into a high-input, high-output system that makes some people very rich but is destroying the planet.

Let’s talk about pesticides specifically. We recently covered research showing that 100% of urine samples tested in Spain contained pesticide traces, regardless of diet.

And in most of those samples, it wasn’t just one pesticide. Many people are walking around with dozens of pesticides in their bloodstream, in their urine. We are basically guinea pigs in a huge experiment. Nobody was ever exposed to a cocktail of pesticides from conception to death until the generation born around 1940. And we’re all now continuously exposed to an ever-changing mixture for decades at a time.

The safety testing done before pesticides are released is nearly always short-term toxicity studies, usually just a few days of exposure. That tells you nothing about a lifetime of exposure. And yet there is growing evidence of links between particular pesticides and all sorts of ill health, particularly in farmers, who are more exposed than most. Parkinson’s disease is now regarded essentially as an occupational disease of farmers. Paraquat and chlorpyrifos have been very strongly linked to Parkinson’s and other neurological problems.

It almost doesn’t require a scientific study to conclude that products designed to kill living organisms might not be great for human health.

No, not at all. I was actually one of the authors of a large review paper recently, where researchers looked at essentially every trial ever published on the impact of any pesticide on any organism. One of the really interesting findings is that each class of insecticide doesn’t just affect its target. Insecticides are obviously toxic to insects; that’s the point. But they’re also toxic to vertebrates, to plants, to soil microbes. Herbicides, which you’d think wouldn’t particularly harm insects, turn out to do so as well.

They’re biocides. And if you reflect on where the first pesticides came from, many of the organophosphates were developed during the Second World War by people trying to create chemicals to kill people. When the war ended, they were repurposed for crops, and apparently no one stopped to ask whether that was a good idea.

The regulatory system seems spectacularly unfit for purpose.

It takes decades, typically from the moment a warning is first flagged by a scientist to the point where enough evidence has accumulated, enough researchers have attended to it, and governments have actually listened and acted. A minimum of twenty years for anything to happen. Meanwhile, hundreds of new pesticides have been introduced to the market. In Europe there are currently around 450 different active ingredients available to farmers; in the United States it’s closer to 1,000. The vast majority have never been independently evaluated for safety.

And the companies that produce these pesticides lobby very hard to prevent any improvements to the regulatory system. They don’t want it to filter out harmful products. It would be more expensive for them if the tests were more rigorous. They’ve done a really good job of blocking reform. There have been many attempts to tighten the European pesticide system, and they’re almost invariably blocked by industry.

It’s much like smoking. The tobacco industry managed to cast doubt on the link between smoking and cancer for nearly fifty years before it became impossible to deny. We’re in a similar situation with pesticides. It’s pretty obvious they’re doing us significant harm, but the lobbying in the other direction makes it very hard to persuade governments to act.

There’s also a problem with the testing itself. Chemicals are assessed individually, not in the combinations people are actually exposed to.

We should somehow test the mixtures, but the trouble is it’s almost impossible to do, because the number of possible combinations is near-infinite and everyone is exposed to a slightly different cocktail. You’d need billions of dollars to even begin to scratch the surface. And those who have billions of dollars are, of course, doing the opposite kind of testing.

A lot of the farmers we work with feel they simply can’t transition away from these products, that they’d lose their crops. How do we change that?

That’s a real barrier, and it’s not irrational. You can’t just stop using pesticides overnight and go organic. If you do, you’ll probably lose your crop. You need to adapt the varieties you’re growing, you need to give time for the natural enemies of pests, whose populations have been depleted by decades of spraying, to recover. It’s not simple.

But there are successful organic farmers out there, and one of the most effective ways of persuading other farmers to try it is simply taking them to see a working, profitable organic farm. If they can see it working somewhere, and talk to a farmer who’s actually done it, they’re far more likely to believe it than if they hear it from an academic like me. No farmer would listen directly to what I have to say. Probably quite right, to be fair.

The other part of the problem is agronomists. They’re supposed to give farmers impartial advice about how to grow their crops. In the UK, the large majority either work on commission or are directly employed by pesticide companies. They’re not impartial. And they’re also incentivised to recommend spraying: if they advise a farmer to spray and the crop still fails, the farmer is unlikely to blame them, at least they tried. If they say don’t spray and the crop fails, they’ll be blamed. So they’re conditioned to recommend spraying regardless of whether it’s strictly necessary. A critical component of a better farming system would be a network of independent agronomists that farmers could actually trust.

You’ve spent much of your career on bees specifically. How many bee species are there, actually?

Globally, 21,000 known species, and probably more awaiting discovery. In the UK alone there are 270 species. Of those 21,000, honey is made by a small number, mainly the honeybee, Apis mellifera, which is the domesticated species kept all over the world. There are about a dozen honeybee species globally that make honey, and a few stingless bee species in the tropics used on a small scale, mainly for medicinal purposes. But the bulk of honey does effectively come from one species.

The large majority of bees don’t make any honey at all because they’re solitary. There’s no hive with a queen and thousands of workers, just a female that makes a nest on her own, and males that fly around trying to mate. If you go into a garden with flowers on a sunny day and spend five minutes watching, it quickly becomes obvious there are loads of different types of bee. In my garden right now you could probably find eight different bumblebee species. And yet most people think there’s one bee, it lives in a hive, it makes honey. If you ask them to draw it, they’ll draw something fat with yellow and black stripes, which honeybees aren’t. The cartoon bee is a bumblebee.

On insect hotels, useful or not? I’ve had conflicting information.

They can definitely be useful. I have about fifteen nailed to my house. They get occupied, particularly in urban areas. Most of mine have bees in them, maybe six or seven species. A few weeks ago there were loads of red mason bees, which are about a hundred times more efficient than honeybees at pollinating apples. So they’re supporting genuinely useful pollinators.

There are downsides. They can become hotspots for parasites and diseases, so some people recommend cleaning them or replacing them periodically. I take a slightly more relaxed attitude, because I’m not trying to maximise my bee population. I’m happy for there to be parasites; they’re part of biodiversity. And frankly, I love sitting with a coffee watching my bee hotels in the morning.

Bear in mind that these bees naturally nest in holes made by beetles burrowing in dead tree trunks. The modern world has very few slowly decaying trees with beetle holes in them. They’re tidied away and burned. So these bees probably struggle to find places to nest unless we give them somewhere. On balance, I think they’re a positive thing.

What can individuals actually do? Is there genuine reason for optimism?

The good news is that insect populations can recover really quickly. They’re not pandas or rhinos, breeding slowly. Give them the right conditions and their numbers can shoot up in weeks or months. And there’s a surprising amount of diversity hiding in urban spaces.

There was a woman called Jenny Owen who lived in Leicester, not a city particularly famed for its biodiversity, with a small garden, about a sixteenth of a hectare. She spent 35 years cataloguing every species she could find: plants, birds, insects, spiders. After 35 years, she had found 2,673 different species in her urban garden. Nearly 2,000 of those were different types of insect. And that’s in northern England. Someone in Spain or southern France would find considerably more.

The steps to get there are simple: don’t use pesticides, grow some native wildflowers, have a pond, don’t mow the lawn too often, put up a bee hotel. Many of those things save you time and effort. And there’s a cultural shift happening, which is genuinely encouraging. A lawn that was previously seen as “abandoned” is now being reframed as “rewilding.” There are still people who complain when road verges aren’t mown, but there’s a growing number who love it. In the UK there are 22 million private gardens covering around 500,000 hectares. If the majority became even modestly wildlife-friendly, that would matter enormously. And if we could get councils on board, road verges, roundabouts, parks, cemeteries full of wildflowers and pesticide-free, that would really help. It wouldn’t solve everything, but it would be a meaningful step with very little downside.

You mentioned light pollution earlier. I hadn’t come across that one as a significant factor.

It’s quite a new topic. The most obvious effect is moths and other nocturnal insects flying round and round streetlights and bashing themselves against them, which clearly isn’t good, and they’re being picked off by bats while they do it. But more recent research suggests other effects beyond just disorienting flying insects. Many insects judge when to emerge from hibernation by the lengthening of days. If they’re near a light that’s on all night, they may lose the ability to detect day length and emerge in the middle of January.

There’s a wonderful, slightly obscure example: an African dung beetle that navigates by the Milky Way when rolling balls of dung. The line of the Milky Way tells it which direction to roll towards the hole it’s dug. If there’s light pollution, it can’t detect the Milky Way, and it wanders in circles. It’s a sad illustration of how many unintended effects we have on the world.

It’s also a reminder of just how interconnected everything is. A beetle using a galaxy as a compass.

It is remarkable. The insect world is full of strange and wonderful things, some of them quite disgusting, but many of them fabulous in their own peculiar ways. And there are thought to be millions of species we haven’t yet named. Who knows what we haven’t discovered.

Finally: what has made you think, “What the field?” lately?

There are so many things to choose from. The one that springs to mind is a paper about cores taken from glaciers in Svalbard, north of Norway, somewhere you’d imagine would be the purest place on the planet. They screened those cores for pesticides. There are layers of pesticides in the snow, corresponding to different periods of use further south, drifting in the atmosphere and depositing as snow at the poles. I just couldn’t quite believe that our impact had extended even to places where nobody ever goes. They’re still being poisoned by pesticides. How depressing is that.

And there was another one. Researchers in the Netherlands screened dust from bedroom floors for pesticides. The average bedroom had 43 different pesticides in the dust lying on the floor. I don’t know what inspired someone to test that, but there it is. We’ve contaminated everywhere. What are we doing.

Eat the Planet Well by Dave Goulson is out now. His documentary recommendation: My Garden of a Thousand Bees, available on streaming platforms.