Gresham College Lectures

Averting the Insect Apocalypse

May 11, 2022 Gresham College
Gresham College Lectures
Averting the Insect Apocalypse
Show Notes Transcript

Recent studies from around the world show insects are disappearing fast. If this continues, this will have profound consequences for mankind and for our planet, for insects provide a myriad of vital ‘ecosystem services’, such as pollination, pest control, decomposition and recycling. 

This lecture looks at the causes of this crisis, at possible solutions including more sustainable farming systems, and at what we can do individually to create insect-friendly habitats.

A lecture by David Goulson

The transcript and downloadable versions of the lecture are available from the Gresham College website:

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- So as you've gathered, I'll be talking to you tonight about insects, kind of my specialist subject. Really, the talk has the same structure as my new book, sorry to get in the book plug right in the beginning, but "Silent Earth," which is all about insects, it's about how amazing, beautiful, sometimes very weird they are, it's about how important they are, the sad evidence that they're declining, and why they're declining, and what we can all do about it. So there is a bit of a depressing bit in the middle of my talk, but bear with me, please don't fall asleep or walk out, the end is more cheerful, and there are things to be positive about. So where do you start? Insects is an enormous topic, insects make up the bulk of life on Earth, more than 2/3 of all known species are insects, so I thought I'd start right at the beginning. This is an artist's impression of the Earth when insects first appeared about 480 million years ago, so nearly half a billion years. They were pretty much the first creatures that we know of to crawl out of the sea and colonize the land, and they were the first animals to really make a success of life on land. They developed, evolved a waterproof cuticle so they could survive even in deserts, and some of them evolved the ability to fly, they were the first creatures to fly on the planet, also, actually, incidentally, probably the first creatures to make noises, to sing, to chirrup, to buzz, and so on. Back then, the oxygen concentration in the atmosphere was higher than it is today, so some insects grew much larger than any that are around today, and there were dragonfly-like creatures with wingspans of about 80 centimeters, imagine these giant things zooming through the early skies, it must have been extraordinary. Anyway, in half a billion years, they've speciated into an extraordinary diversity of different shapes, and sizes, and colors, and life histories, and so on, just remarkable. Even in the UK, we have an extraordinary diversity of weird and wonderful insects if you take the time to look for them. So I thought I'd start off by just showing you some pictures of some interesting insects, nothing more taxing than that. So here we are, isn't that a lovely creature, very sweet, this is an acorn weevil, it's a British species. Weevils are a type of beetle, and beetles are the most successful family of organisms on the planet. Just the weevils alone, there are 97,000 known species of weevil on our planet. There's a famous quote, there was an evolutionary biology called J.B.S. Haldane, who died a few decades ago now, but he was once asked in an interview what his studies of evolution had taught him about the nature of God, and he was an atheist, so his probably facetious response was he must have an inordinate fondness for beetles, obviously he spent a very long time making them, if you believe that he did. Anyway, let's move on. Insects, as we'll see later, are really important as the base of the food chain, many larger organisms feed on insects, which of course the insects don't like, so many of them have evolved a whole array of ways to try and avoid being eaten, including, for example, astonishing camouflage, this bush cricket has evolved to look like a leaf with false veins on its wings, and so on. This is a photograph I took in Ecuador a few years ago, the forest floor. I don't know how many you can count, but I think there's eight different species of moth hiding there, I'll leave you to see how many you think you can see, but just an extraordinary example of camouflage. These things sit around all day, there are lots of birds in the forest, I can see you're all just too bust counting now, aren't you. (audience laughs) Anyway, I think the answer is eight, but I'm not entirely sure, there's at least eight, let's put it that way. Other insects appear to be very poorly camouflaged. This beautiful thing is an orchid mantis, which has evolved to look like the petals of a flower, which you'd think would make it a really obvious target for predatory birds, but of course they think it's a flower, so they don't try to eat it, and that serves the double purpose that pollinating insects might think it's a flower too and try to visit it, in which case they get eaten, and this is the wing of an unfortunate butterfly, the rest of which has just been consumed. Some insects have stings, bees and wasps, for example, and that means that predatory animals tend to avoid trying to eat them, but then other insects have evolved to pretend to be things with stings, bees or wasps, and so this here is a completely harmless fly, this is a British species, it's pretending to be a bumblebee, and I think it would fool most humans. If you're interested, the easiest way to tell it's not a bumblebee is the fact that it has really tiny antennae, if that was a bee, it would have quite big, long, thin, black antennae, should you ever spot one and be interested to know what you're looking at. There are also insects which are poisonous. Many of them become poisonous by sequestering poisons in the food they eat, in the leaves they eat, and they store the poison in their body, and then they advertise that they're poisonous to potential predators, 'cause there's no point in being poisonous but the predator doesn't realize that until it's eaten half of you. So for example, this cinnabar moth is a British species, I get them in my garden, they're very common, it eats ragwort, and ragwort is famously poisonous to animals, and the cinnabar moth caterpillar sequesters the ragwort poisons in its body, and then it advertises to the world, coincidentally using exactly the same warning coloration as a bee or a wasp, saying, don't try and eat me, you'll be ill if you do. These are some other beautiful poisonous insects I've seen over the years. There are also just some weird insects, and we have really no idea why they look like they look. This is a little planthopper, a relative of an aphid or a froghopper, found in Central America, and it exudes little strands of wax out of its bottom which grow, and grow, and grow, and look like a bundle of optic fibers, really extraordinary, nobody has the foggiest idea what possible purpose that might serve. When they jump, they can drift a bit like a dandelion seed, so maybe it's a really odd dispersal mechanism, but no one's really sure. Some insects are just extraordinarily beautiful, but so small that nobody really notices them. For example, in the UK, we have half a dozen species of ruby-tailed wasps, which are absolutely stunning, and you will find them in gardens, parks all over Britain, but most people have never seen one simply because they're only about seven millimeters long, so it's really easy to overlook them, but what a beautiful creature, it looks like it should live in a rainforest, or somewhere exotic, but no, you could probably find them round here. Just to finish off, there's even a shield bug that does a pretty good impression of a jaundiced Elvis, (audience laughs) but obviously not deliberate. My specialty are bees, I've been studying bees now for about 30 years. Bees evolved relatively late. If you recall, I said insects first appeared about 480 million years ago, the first bees didn't appear until about 120 million years ago, which sounds quite recent in comparison, it's still in the middle of the age of the dinosaurs, before, for example, Tyrannosaurus rex evolved, so quite a while back. Bees evolved from wasps, they're essentially wasps turned vegan. The ancestor of the bees would have been a solitary wasp which made a little nest in the ground and stocked it with paralyzed prey, it could have been caterpillars or spiders, there are still wasps that do this to this day, and then laid its eggs on the paralyzed larder that it had stored. But the ancestor of the bees starting using pollen instead of paralyzed prey items, and that basically became the first bee, and that seems to have been a pretty successful strategy, and just as the insects proliferated, so have the bees, and there are now about 25,000 different species of bee in the world, and they come in an amazing array of shapes, and sizes, and colors. I'd love to see this one, I've never seen a bright blue, fluffy bee, you've got to go to China, unfortunately, but one day perhaps. Anyway, just to rewind a bit, I first became interested in insects when I was a kid. This isn't me, this is my 11 year-old son a couple of years ago, Seth, my youngest, who is still in a bug phase. I think lots of kids go through a bug phase, and he loves nothing more than to catch insects, and keep them in jam jars, and feed them, and look after them, and whatever. This is Colin, his cockchafer, who's sadly no longer with us, but anyway. I never grew out of that bug phase, but sadly, most people do, most teenagers and most adults these days, their reaction to anything that buzzes near them is usually more fright than anything else, they flap around, they try to kill it, they think it's going to bite them or sting them, which is really sad, and I guess my mission in life now is to try and persuade people to love insects, or at the very least to respect insects, because as we'll see in a little while, insects are incredibly important, love them or loathe them, we need them, and they're in decline, so onto the dark and depressing part of the talk. I should say we don't have good longterm data on populations of most insects because nobody's counting them, there are too many species, too few people who can identify them to provide us with data, but some insects are quite well monitored, and probably the best of all are British butterflies, which have been counted in a national monitoring scheme by keen amateurs since 1976. Here, they've been divided into the commoner butterflies and the rare habitat-specialist butterflies, both have declined by different amounts. Overall, butterflies in the UK are about half as common as they were in 1976. Coincidentally, I was 11 in 1976, the same age that my youngest son is now, which means that he's growing up in a world in which he sees half as many butterflies as the world I grew up in, which is quite depressing. But what I guess really concerns me is what will his children think is normal, will they see any butterflies, or bumblebees, or other insects? It isn't just butterflies that are declining, we do have a whole range of datasets from different parts of the world, mostly from Europe and North America, for different insect groups. One of the best known studies in this area came from Germany, it was published in 2017. I was one of the authors of this work, but I didn't really do a great deal to deserve that. Anyway, keen, amateur, German entomologists popped these things, called malaise traps, on nature reserves all across Germany from 1989 onwards, and malaise trap catch flying insects, most insects fly, at least as adults. And what this shows here is the daily weight, the biomass, of insects caught per trap, per day all across Germany from 1989 to 2016, and you can see the weight fell, it actually fell on average by 76%. So in 26 years, seemingly 3/4 of the flying insects have disappeared right across Germany, which actually tallies pretty well. There's a study coming out tomorrow, I was asked to comment on a press release, done in Kent, a splatometer test using cars, which asked people to count the number of splatted insects on their car number plate, which seems to show a very similar magnitude of decline. Actually, I had a strange experience relating to this paper. I mentioned, I think, it was published in 2017, and there was a lot of media interest around the world, I think it was the first time that there was a widespread awareness that there was a serious problem with our insects, and I was in the pub, I was on my way to Dorchester to give a talk, and my mobile phone rang, and it was an Australian radio show, they wanted to interview me about this insect decline story, and this paper, and they wanted to interview me in 10 minutes' time, and I slightly panicked, I thought, okay, I guess I can do that, and they said they'd ring me back. And I thought, the pub was really noisy, there was a jukebox playing, and I looked outside and it was raining really heavily, and so I thought I'll go into the toilet and take the call in there. So I went into the men's toilet, and stood there, and the phone duly rang, and it was the Australian radio host, and he said, are you ready to do the interview, and I said, yeah, okay. Of course, as soon as it started and I was live on air, broadcast to, I've no idea how many Australians were listening, someone came in and started urinating rather loudly, (audience laughs) and I had this horrible feeling that all these Australian people would think it was me. (audience laughs) Anyway, the first question that the host asked was, so, the insects, I won't do the accent, the insects are disappearing, that's a good thing, isn't it? I think it was a tongue in cheek, provocative question, but nonetheless, I think it does kind of exemplify many people's attitude to the disappearance of insects. Most people associate insects, bugs, creepy-crawlies, they have negative connotations to most people, and therefore, if they're disappearing, they don't realize that that's actually a problem. I'll come back to that in a second. One more piece of evidence, in case I haven't convinced you yet. We don't, sadly, have any longterm population data for bees of any type. We have started counting them, in a similar way to the butterfly scheme, but we only started quite recently, so we don't have longterm trends, but we do have maps, and we can see what's happened to the ranges of bees over time. I'm just going to show you this one example, it's a really lovely, little bumblebee, a UK species called the shrill carder, so called because it has a slightly higher pitched buzz than most bumblebees, and once you've heard one, you can get your ear in for it, and you can often detect there's one near you before you see it. Anyway, sorry, where were we? It used to be common all over the southern half of Britain, pre-1960, but as time has gone on, it's rapidly disappeared. I became interested in bumblebees, and their declines in particular, in about 2000, and at the time, this bee was known from about six little population clusters around the UK. I, at the time, was based at Southampton, and I wanted to see one of these bees for myself, so I went to Salisbury Plain here and spent the whole summer hunting for them, and eventually found a couple of them, and got really excited. But since 2000, that Salisbury Plain population has disappeared, and in the last couple of years, the one on the Somerset Levels seems to be disappearing, there's only a couple of bees been seen in the last few years. This bee is still disappearing, it's going to go extinct pretty quickly if we don't do something about it, so these are not historical declines, they're happening now, and they're still going on, which we should be really worried about, because, as E.O. Wilson said, insects are super important, I won't read his quote. E.O. Wilson, he died a few months ago, sadly, in his 90s, amazing scientist and ant specialist. Anyway, he basically said if people vanish from the planet, the planet would do very nicely without us, but if insects were to vanish, "the environment would collapse into chaos," was how he put it. And he's absolutely right, and I just want to run through, in case you don't know, why insects matter. I've already mentioned they make up the bulk of life on Earth, they're then food to a very large proportion of the remaining organisms, things like many species of bird, and bats, and lizards, and frogs and toads, and freshwater fish like trout and salmon, they all depend upon insects, so if the insects disappear, then they're going to be in trouble. And in fact, we've seen disproportionately rapid declines in organisms that eat insects. There are two specialist insect-eating birds, the cuckoo, which likes to eat hairy caterpillars, and the spotter flycatcher, which, as the name suggests, likes to eat little flying insects. Birds are monitored more carefully, and have been counted for longer than any insect group, since 1966 in the UK, and you can see both of these birds have undergone really dramatic declines. I remember cuckoos, the sound of cuckoos when I was a kid was common everywhere in lowland in Britain; haven't heard one this year, didn't hear one last year. As you can see, 77% have disappeared, and much worse for the poor, old spotted flycatcher, which, again, used to be a common garden and parkland bird, but now you're very lucky if you see one. Rather terrifyingly, actually, the British Trust for Ornithology, who collate these data, they calculate the total breeding bird population of the UK, and how it's changed over time, and according to their estimates, the number of breeding birds in Britain has declined by an average 92 birds per hour since 1966, isn't that a terrifying thought? Every hour, 92 fewer birds. So insects are important as food, they also do a whole bunch of other stuff, they're involved in more or less every ecological process you can think of, they're bio-control agents of crop pests, admittedly the pests themselves are often insects too, so not all insects are helpful, they're involved in recycling of, for example, dung by dung beetles, dung flies, and so on, and dead bodies, that's a carrion beetle, and of course maggots help to tidy away dead bodies too. Some are involved in keeping the soil healthy, they distribute seeds, they do all sorts of stuff that we take for granted, or are completely unaware of, most of these things are things that people don't really think about. There's just one thing that insects do that I think is widely appreciated, and that of course is pollination. Many people wrongly think that pollination is done entirely by bees, some people think it's done by one species of bee, the honeybee, that's far from the truth. There are, as I've already said, 25,000 species of bee, but there are probably hundreds of thousands of species of pollinating insect in total, including moths and butterflies, and lots of species of flies, and wasps, and beetles, and so on, and altogether, they ensure that plants set seed and continue to exist. 87% of all plant species on the planet need pollinating by some kind of animal, and in the tropics, sometimes that's done by a hummingbird, or a bat, or even, in one or two strange cases, by mammals, and even lizards, but usually it's by an insect, and in Europe, it's always done by insects, we don't have any vertebrate pollinators. Without without all these little insects, then, most of the plant species on our planet would disappear. And, of course, there's a direct link to humans here, which I think most people are aware of. We've become used to our shops being replete with this amazing selection of fruits and vegetables available 12 months of the year. If we didn't have insect pollinators, it wouldn't look so good. Roughly 3/4 of the crops that we grow in the world wouldn't give a full harvest if they weren't pollinated by insects, so we wouldn't have things like apples, cherries, blueberries, strawberries, raspberries, tomatoes, squashes, chili peppers, even things like coffee and chocolate depend upon insect pollination, so life would be dire indeed if we didn't have those little creatures. And the obvious reality is that people would die, lots of people would die, would starve to death if we didn't have all this food, so we've got a really direct reason to value insects. I trot this argument out endlessly, I don't know how many times I've explained to all sorts of people, including Australian radio show hosts, why insects are important, but I've always been slightly dissatisfied by this because it's just valuing insects for what they do for us, it seems actually quite a selfish way of looking at it. And it worries me that there insects that perhaps don't do anything important, at least as far as we're concerned. And the more I think about it, the more examples I can think of of insects that probably could go extinct and it would make not the blind bit of difference to us humans, so are they therefore expendable, can we just let them go extinct? So here's an example, this is the St. Helena giant earwig. I'm sure you've never heard of it, but it was a splendid creature, not quite this big, but about three inches long, the biggest earwig that ever lived on our planet, only lived on St. Helena, which is a tiny, little island in the middle of the South Atlantic, so none of us were ever going to see one, lived in seabird colonies and scavenged on bits of detritus and seagull poo, presumably, we don't know, because it's extinct, and no one can therefore study it. It's been gone since the 1960s, probably went extinct 'cause they were all eaten by accidentally-introduced rats. Anyway, there was no ecological disaster unraveled because there were no giant earwigs to clear away the seagull poo, or whatever it was they did, St. Helena appears otherwise unchanged, but isn't the world a slightly sadder place because there isn't a giant earwig on St. Helena? I could think of examples much closer to home than that, but my point is that we shouldn't just value the rest of life on our planet if it does something for us, that just seems incredibly self-centered. Most of these creatures have been around for millions of years, much longer than we have, surely these creatures deserve a place on our planet as much as we do. I'm often asked what's the point of mosquitoes, what's the point of slugs, or wasps, or whatever. You could turn it round and say what's the point of humans, or to put it another way, just because we have the ability to wipe out other species, surely it doesn't give us the moral right to do so, I don't think it does anyway. If we're going to reverse insect declines, we need to understand why they're happening. Actually, this is a big and complicated subject, and I could bore you for hours about it. Still, probably the biggest driver is loss of habitat around the world, we're still burning down and chopping down rainforests, and so on. And associated with loss of habitat has been the ever increasing extent of industrialized agriculture and the pesticides associated with it, and that's a big driver, and I'll say a little bit more about that, but there are lots of others that I haven't got time to talk about, things like climate change, the spread of invasive diseases, and light pollution, and so on, and so on, you'll just have to read my book if you really want to know. But I'll say a tiny bit more about habitat loss and industrialized farming. I took this picture off the internet, it could be anywhere, I think it's South America, but it really doesn't matter where it was taken. There used to be a natural community living here, there would have been, who knows, maybe it was grassland, maybe it was forest, there would have been lots of different species of birds, and insects, and flowers, now there's almost nothing, there's just a crop, an almost pure monoculture stretching to the horizon. We've scraped away all of the life that used to be there, and pretty obviously, that massively reduces biodiversity, and we're doing this on an ever bigger scale around the world. This kind of agriculture is only really possible with lots of chemical inputs to control pests and to boost the fertility of the crop, and pesticide use continues to grow globally year on year. When I created this slide, the best estimate was that we were currently manufacturing and spraying about 3 million tons of pesticides onto our planet each year. Pesticides are basically poisons designed to kill something, maybe insects, maybe weeds, it might be fungi, it might be molluscs, but they're all toxins. Actually, this is already out of date, it's now about 4 million tons, it's gone up in the last couple of years. That said, we should think ourselves fairly lucky in Europe because in Europe, there is a fairly strict pesticide regulatory system which has banned at least some of the worst chemicals, it's better regulated in Europe than anywhere else. If you live in North America, you might be accustomed to this kind of thing, this is a common way of applying pesticides in the Americas, from a crop duster, which is incredibly indiscriminate, you can actually see the spray drift just going on the wind, who knows where that will end up and what it will kill. Thankfully, we don't allow that here. But this is nothing compared to this. It might not seem quite so bad, but let me explain. In the developing world, there are very few restrictions on what pesticides can be used, and often, pesticides which are banned in Europe are still manufactured in Europe and sold to developing countries. I took this picture about three years ago just outside Calcutta, this guy has a small farm, about a hectare, he grows fruits and vegetables, and he sells them in markets in the city. It sounds like a really sustainable, nice setup actually, but what he's doing here is quite chilling, he's spraying paraquat, which is a herbicide, it's a herbicide that's banned for use in Europe because it's really, really poisonous to people. If he were to accidentally swallow a drop of it, it will kill him. He's had no training in use of this chemical at all, he's using ancient spray equipment, I don't know what exactly this old brass pump is, and obviously he's just got a plastic can around his neck with the pesticide in it, he's not wearing any protective clothing at all. If he was using pesticides in Europe, he'd have to be wearing a suit, and mask, and everything, but he hasn't even got shoes on, poor guy. The paraquat he's spraying was almost certainly made in Huddersfield, we still make most of the world's paraquat here, and are happy to seel it to the Third World even though it's far too dangerous for our own farmers to use. It does seem astonishing hypocrisy to me. Just to finish off ranting on pesticides, actually, it's not entirely finishing off 'cause I will come back to them once more later, but anyway, I just wanted to illustrate the scale of this, this is not just something that's happening locally on farms in one or two places in the world. There's a really interesting study that was done in Switzerland, which is sort of a citizen science study. Some Swiss scientists were interested in a particular group of insecticides called neonicotinoids. They became notorious because of growing evidence that they were poisoning bees. They're neurotoxins that are really poisonous to all insects in fact, it's a bit like Novichok for insects, it just takes a few billionths of a gram to kill an insect. What these Swiss scientists did was they put out a call for anyone going on holiday to buy a jar of honey and bring it back, and each of these dots represents a jar of honey. They screened the honey for these neonicotinoid pesticides. The white samples of honey were ones without any pesticide in, but they only make up 25% of the dots on this map, so 75% of honey samples from all over the world, including even remote islands in the Pacific, and so on, were contaminated with neurotoxic insecticides designed to kill insects, which is obviously really worrying for honeybees, but actually, it should be really worrying on a much bigger scale than that, because the honeybees are picking up this poison by visiting contaminated flowers, if the honeybees are being poisoned, that means that the tens or hundreds of thousands of other species of pollinating insects all over the world are also all being poisoned, which is a pretty terrifying prospect given how much we need pollinators. Okay, so enough doom and gloom, what can we do about all this? There is good news here. Lots of environmental stories are deeply depressing, partly at least because you feel so helpless. When you see the news footage from the Amazon of Bolsonaro allowing forests still to be burned down, and so on, it's just so depressing, and you don't think you can do anything about it, but with insects, they live all around us, they live in our parks, they live in our gardens, most of them haven't gone extinct yet, and they can recover really quickly, much faster than pandas or rhinos, just give them the right circumstances, somewhere to live, something to eat and they can proliferate really fast, so we could enable them to recover, or at least many of them. And we can all get involved in doing it, and I think that's the particularly exciting thing. So what do we need to do? Well very crudely, four different things we need to do, and I'm going to talk a little bit more about these. We can make our urban areas more insect-friendly, more wildlife-friendly, we need to think about farming and how we can make that more wildlife-friendly, I think we need to put back some of our beautiful flower-rich meadows that we used to have. Britain had, in 1930, we had about 7 million acres of lowland hay meadows, which look like this, full of flowers. By 1987, we'd destroyed 97% of that habitat, it was just swept away and replaced by silage fields, which are monocultures of rye grass. But we know how to restore it, there are projects ongoing right now replanting this beautiful habitat, it can be done. We can't probably do it everywhere, we do need to grow crops, and so on, but we could certainly put back some of what we lost. And we need to stop spraying so many pesticides, as I've already explained. So let's focus on gardening. You might think that gardening for insects is a bit trivial in the grand scheme of things, but I don't think it is. There are about 22 million gardens in the UK, which collectively cover an area of about a million acres, about 400,000 hectares, and that's excluding the parks, the road verges, the roundabouts, the cemeteries, and all the other urban green spaces, just imagine if most of the gardens in Britain were wildlife-friendly, and we could get the councils onboard so that the road verges were all full of flowers, and the roundabouts were full of flowers, and free of pesticides, and so on, that would be a national network of insect-friendly habitat, that would really make a difference. And what's more, it's achievable in quite a short space of time, and it's already happening, there are lots of people who want to invite more nature into their lives, into their gardens, into their local park, and actually doing it, choosing plants deliberately to encourage bees, and so on. And there are councils coming onboard changing their mowing regimes of road verges, and so on, so this is actually already happening, and I think that's really exciting, it isn't just a crazy pipe dream of people like me. As you can probably tell, I'm quite excited about this, and I've written books about it, sorry for another book plug, but there you go, "Garden Jungle" and "Gardening for Bumblebees" if you want to know more about the detail about how to invite nature into your gardens. Of course, inviting nature into our gardens, as well as looking after nature, it has a second purpose, it means that kids can grow up in a world where they encounter bees, and butterflies, and so on, which I think is really important. It's amazing how much life can live in a garden, even a small garden. There's a really interesting study from Leicester, there's a lady called Jenny Owen who wrote a book called "The Wildlife of a Garden." She only had 1/8 on an acre, so a pretty small garden, quite close to the center of Leicester, but she spent 35 years cataloging every species of animal and plant she could find in her little garden, and after 35 years, top marks for dedication, her species list was 2,673. Isn't that extraordinary. I would have guessed that would be the number of critters you might find in a bit of rainforest, or something, not in the middle of Leicester, so it just goes to show we can all have thousands of species living around us if we just have a little bit of space and manage it the right way. What is the right way? Well it's quite a big topic, and I haven't got time to go into lots of detail. The first thing people think about is what plants should I grow, and as a crude rule, old-fashioned cottage garden herbs, biennials and perennials tend to be good, and native plants tend to be good. If you want to know more, I've got lots of YouTube videos, as well as the books, which talk about the different plants that you might grow in your garden should you be interested, check them out. Wildflowers, there have been a number of scientific studies which show that, on average, native plants tend to attract more insects, more wildlife than non-native plants, and that shouldn't really surprise us because native plants and native insects have co-evolved together over thousands of years, so if we could all grow a few more native wildflowers in our garden, that would certainly help. Which brings me on to the subject of weeds, these are all ways that we can get more flowers back into urban areas, and number one for me is trying to persuade people to be more tolerant of certain plants which, for some reason, we have branded as undesirables, we've called them weeds. The word weed is an artificial concept, one man's weed is another man's wildflower, so things like dandelions, beautiful native wildflowers, but many gardeners spend countless hours digging them out, poisoning them, trying to get rid of them at all costs. Similarly with ragwort, and thistles, and a host of other common native beautiful wildflowers. Pollinators love this stuff, dandelions are a really fantastic resource of pollen and nectar in early spring. So I say to people, you can get rid of all the weeds in your garden just like that, just call them all wildflowers. (audience laughs) Moving on, flowering trees can be fantastic for pollinators. This time of year, my garden is full of blossom trees, apples, and cherries, and so on, covered in pollinating insects, and if you choose wisely, you can have blossom right from March through to June, which provides a continuity of forage for insects, and of course they return the favor by pollinating the crops and giving your own homegrown, zero-pesticide, zero-food miles fruit, what's not to like? We should mow less, this is something that there's a big campaign on at the moment, No Mow May. It's a strange thing that, in the UK, many people are obsessed by trying to recreate something that looks like a Wimbledon tennis court in their back garden, they mow up and down in dead straight lines trying to get that little stripy effect. I've no idea why. If you can just persuade yourself to be more relaxed and let the grass grow up a bit, usually, it's full of flowers. That's my lawn, and I haven't sown any flowers at all, it's just what came up if I don't mow, which I don't terribly often. So if you're a mower, next time you start to twitch and you think the grass is too long, if you can restrain yourself, don't get the mower out of the shed, get a deck chair out of the shed and make yourself a coffee or a gin and tonic and sit down, and relax, and enjoy the insects. And then of course there's mown areas in all of our towns and cities, and many of them don't seem to need mowing. The council will pay teams of people to come out eight times a year typically to mow, and mow, and mow through the spring and summer, road verges, roundabouts, and so on. We could save an awful lot of sweat and petrol by instead growing wildflowers. This is an example of a road verge from up in Stirling, in Scotland, which was taken over by a little local campaign group called On the Verge, and they basically spend their weekends sowing wildflowers, they dig over any bit of mown grass they can get permission to attack. And at the last count, I think they've got 94 patches like this, there's roundabouts and road verges, they've got one next to a rugby pitch, one in a primary school field, and even a patch of wildflowers in the local women's prison in Stirling. Wouldn't it be great if every road verge all around Britain looked like that, that would really help, I think. Instead, what you see all too often in our cities and towns is this kind of thing. You can probably guess what this is, this is vegetation that's been killed with herbicide. You see this all over the place once you've got your eye out for it, this horrible, dead, yellow vegetation. That was just a bit of grass growing around a tree, what harm was it doing? It probably didn't support terribly much life, but there would have been a few insects in there, now it looks dead, does that look better? It looks awful to me, I just don't understand why local councils, they employ teams of people to drive around the streets looking for something green and killing it, it doesn't make any sense to me. So aside from being seemingly just needless environmental vandalism that we pay for through our taxes, there's also a more sinister aspect to this, which is that the chemical used is almost invariably Roundup, which is based on a compound called glyphosate, and there's pretty clear evidence, disputed by the manufacturers, of course, but pretty clear evidence that glyphosate causes cancer in people, particularly people who use it as part of their occupation, like the people who sprayed this, and yet we're happy to spray it on children's play equipment in parks, it just seems completely bonkers to me. I personally think we should ban urban pesticides completely and we should stop them being sold to gardeners and the local council. And if you think that sounds quite extreme, France have already done this. In 2018, they introduced a law that meant only licensed farmers can buy any kind of pesticide, so Paris is now pesticide-free, and it hasn't been overrun with dandelions and giant cockroaches, it still seems to be fine. If Paris can do it, why can't London do it, why can't the whole of Britain get rid of these things in our gardens and parks? We just don't need them. I've just got a couple of minutes to say a tiny bit about farming before I wrap up. We can make urban areas good for wildlife, and that's really exciting, and is happening, but it isn't going to solve all of the problems, urban land doesn't cover enough of Britain, by far the bigger area is farmland, 70% of Britain is farmed, and most of that land is pretty hostile to life, for the reasons I've already discussed. But I think many people accept this kind of industrialized farming as necessary, a necessary evil if you like, the only way we can feed the ever-growing human population. I actually think that this approach to farming isn't sustainable, and if we carry on, then people in the future will starve, because of at least three reasons. Firstly, this industrialized approach to farming is undermining its own basis by wiping out the biodiversity that it depends upon, we need the natural enemies of crop pests to control the pests, we need the pollinators to pollinate the crops, and yet this type of farming is wiping out those creatures it depends upon. It's also doing terrible damage to soil, there was a recent report from the United Nations that 40% of the world's soils are already badly degraded. What will future generations grow their food in if there's no decent soil left? And finally, food production, this kind of industrialized food production produces lots of greenhouse gases, about a third of all greenhouse gases come from food production one way or another, and we all know that we have to rein in climate change, so we can't carry on doing what we've been doing up 'til now, I don't think. So what should we do instead? Well it's kind of interesting, I think, to just think what would we want from our farming system. It obviously needs to produce enough food to feed everybody, ideally to feed everyone a nice, healthy diet, which actually the current system fails to do, but it does need to look after the soil so that future generations have something to grow their crops in. I think it has to work with nature, it has to support healthy pollinator populations, it needs to support those natural enemies of crop pests, it needs to support all the creatures that live in the soil and help to keep it healthy, which probably means that it needs either massively reduced or no pesticide use. And that seems like quite an ambitious list, but there are actually already types of farming which seem to do all of this, and these are just a few examples, I haven't got time to tell you about them in any detail at all, but things like agro-forestry, and permaculture, and biodynamic farming, organic farming, all of these are very much focused on looking after soil health, not using pesticides, they all involve a much greater diversity of crops, and the ones I've visited, so for example there's a lovely biodynamic farm in West Sussex that I've been to many times. I was a little bit skeptical at first 'cause biodynamic farming does involve a little bit of wizardry, they make potions, but most of what they're doing, 99% of it is incredibly sensible, and if you visit a biodynamic farm, you'll see the soil is full of earthworms, and it's rich, and dark, and healthy, they've got this incredible diversity of different crops that they grow, all of which seem pretty healthy, and in terms of productivity, they produce a lot of food. We've looked at the production per hectare and it compares really favorably to industrialized farming methods. And it's teeming with life, so you can have nature and food production in the same place, and it seems to me we should invest more in these kinds of areas and try and move away from the industrialized approach. Whatever we do, we need to do a better job of looking after this. It's an extraordinary thing, we don't often stop to actually think about the fact that we are clinging to the surface of a rock hurtling through space with a few million other species castaway with us, if you like, it's our home, it is everything we have. Whatever Elon Musk thinks, we aren't going to go and live on Mars anytime soon. It's a source of wonder and inspiration, and I don't understand why we're being so reckless with it, and it really worries me that future generations are going to inherit an impoverished Earth. We would all do anything for our children, wouldn't we, apart from leave them a decent planet to live on, I don't understand. Anyway, we can do better, and what better place to start than by looking after all the little insects that live all around us. Thank you everybody for listening. (audience applauds) - "Villages which compete in the Village in Bloom events "seem to choose geraniums, begonias, "and busy lizzies, et cetera, "or double blooms "which are of no use to pollinators, "whilst at the same time "weeding the verges for neatness. "How do we raise awareness to change this?" - That's a good question, and it's absolutely true that we do grow and plant an awful lot of these, I think, fairly hideous annual bedding plants, these really showy things that you see in hanging baskets, and so on. It's all about education, I think if people realized that if you plant some native wildflowers, or just some traditional cottage garden herbs, and so on, you can attract and feed a whole host of amazing insects, whereas if you grow a pelargonium from South Africa, you'll feed almost nothing, it's just dead space. It's a case of just simply getting that message across, I think. Everyone wants to help wildlife, we all want to help the bees, don't we, but most people don't really know how, so it's all about educating people to grow the right plants. - [Questioner] Could we go back the caption which showed the shrill carder, it showed the decline of that species? I remember seeing that it was left concentrated in the Thames Estuary and the West of England. Why is that, please, in those areas? Thank you. - The shrill carder, why is the shrill carder thriving, apparently, relatively thriving here? There are lots of coastal marshes which are quite rich in flowers, and because they're marshland, and they flood occasionally, they're not very good for farming, so they tend to be not intensively farmed, it's as simple as that. Actually, I should mention, there are some really interesting brownfield sites in the Thames Estuary, abandoned sites, like Canvey Wick, where you can find the shrill carder. Canvey Wick used to be an oil refinery, but it was abandoned 30, 40 years ago, and it's a really beautiful illustration of how nature can recover if we just leave it alone. All that's happened is that people walked away, left it as contaminated land, and now it's got this really rare bumblebee there. so largely, nature, all it needs is some space and freedom from us messing around with it. - [Questioner] What's the most common pushback by local councils around wild gardening, essentially, and the use of pesticides which cause cancer, allegedly? - The most common pushback from councils? I think the pressure on councils, a lot of it come from people who complain if the verges aren't cut, if the park isn't cut, they think it's laziness on the part of the council, and they don't realize that it can be an active choice in favor of nature, so it's about making that clear. I would advise councils to put signs up if they're not going to mow a road verge and leave it to go into bloom, then put a sign saying, wildflower strip, and people are much less likely to complain, but it's those complaints that make them mow. And very often, they get more letters of complaint than they do of congratulations. As a species, we like to complain and we don't often bother to congratulate. So if your local council do leave ares of a park, or road verge, or whatever to grow, write them a letter and thank them, and if everyone did that, and the councils got more letters of thanks than complaint, they'd carry on. So I think making it clear to the councils there's public support is key. - I've got a question here online that I'd like to bring in, here's someone, clearly a fan of yours, "After reading some of your books," which implies she's reading quite a few, "I'm concerned about the fact "that so many plants are treated by pesticides "before being sold. "I can't quite get my head around "the longterm impact of this. "Is there a point when the planet becomes safe again?" - Not anytime soon, I fear. Something I didn't mention in my talk is that if you go to a garden center and buy a pretty plant, a bee-friendly one or otherwise, and they do often badge bee-friendly plants with a logo, they often use the Royal Horticultural Society perfect for pollinators logo to badge plants which are attractive to insects. What nobody tells you is that those plants will almost certainly have been treated with a whole bunch of pesticides. And a couple of years ago, we did some research, we tested the nectar and pollen of plants being sold by garden centers as bee-friendly, and nearly 100% of them contained pesticides, in fact, 75% of them contained these neonicotinoids that I mentioned earlier, so they're not bee-friendly at all, far from it. But when will the planet become safe again? When we stop poisoning everything, obviously, that would help, wouldn't it, but we don't seem set to do that anytime soon, sadly. - [Questioner] Thank you. Thinking about the produce element of this in terms of the interventions, and the agricultural industry, and I'm just interested in your view of, to what extent is the fix switching those methods of production, versus government regulation and subsidy, versus expecting consumers, through education, to pick up the economic discrepancy in cost? - It's an interesting one, how do we make this transition towards more sustainable agriculture, which we clearly need to do? It could be done any number of ways, it could be driven entirely by bottom-up consumer pressure if enough people were aware. To be very simplistic, if everyone bought organic food, there'd be no pesticides in the world, but I don't see consumer pressure being that powerful anytime soon. The alternative, of course, would be for a top-down, government regulation approach, which actually could be done really swiftly because of the farming subsidy system. We basically pay, at present, about 3 1/2 billion pounds a year to farmers to farm, essentially, taxpayers' money, 60% of farmer income is subsidy in Britain, it's the only heavily subsidized industry in the country, and that gives us a mechanism, you could completely turn the subsidy system on its head and you could give much more money to, for the sake of argument, biodynamic farms, or organic farms, or whatever it was you wanted to support, and that would transform the landscape in just a few years. But again, that would require the government in power to really buy into this, and sadly, I don't think they do. Sorry, this is a long answer. There is an interesting development at the moment, which is this ELM scheme, Environmental Land Management scheme, which is a new iteration of the farm subsidy system, which sounded as if it might be quite an important step in the right direction, but it seems to be being watered down in its implementation, and we're all sort of waiting for the final version of it to come out. Michael Gove made it sound as if it was going to be great, and seems to have since backtracked, unfortunately. One way or another, maybe we need a mix of bottom-up support, and we need to vote for politicians that will introduce the top-down regulation that we need to, one way or another, transition into more sustainable food production, but if we don't, then all of these problems I've talked about are going to continue, sadly. - Time for a quick couple more here, I'll just take one from online which I think other people in the room might want to know the answer to, the question about the contaminated plants from garden centers. This person says, "Is it then safer to plant from seed "rather than from a plant you buy?" - Yes it is, plant from seed, buy from an organic nursery, and there are a few around, and some of them deliver online, Rosybee Nursery and Bee Happy Plants are two off the top of my head, or do plant swaps with friends and neighbors, which is probably the most sustainable way, and the easiest way to get healthy plants. Look over your garden fence, if your neighbor's a gardener, they'll happily give you bits and pieces of surplus plant, and what thrives in their garden will thrive in your garden, so it's much better than going and spending a fortune in the garden center buying a whole bunch of poisonous plants grown in a peat-based compost in disposable plastic pots, which is basically what garden centers are all about. - [Questioner] It's more of a comment really. I am a councilor in Southwark, and since I got elected, I've been pushing to improve biodiversity, and what I would do is encourage everyone in this room to write to your local councilors and your cabinet members, and make it clear that you don't want them to use glyphosate in particular. What we've done on the estates in Southwark, where I'm a councilor, we've encouraged them to not use any pesticides and not mow for a couple of months, not just during No Mow May, or whatever it's called. And I just wanted to thank you for your brilliant book, "The Garden Jungle." As a consequence, I've set up a little organization in Southwark to try and re-wild one square mile, and we're getting different organizations involved, so I just wanted to thank you very much for that brilliant book. - Thank you, and hear, hear. - Tremendous, ladies and gentlemen, to end on an absolutely positive note, I'm sure Professor Goulson would take more questions from those of you in the room afterwards, but it's seven o'clock, so we must end, and I'd like to thank him very much for a tremendous talk, thank you very much.