Dave Goulson is a British biologist actively working for the protection of the environment. He is a professor of Biology at the University of Sussex and has been widely recognised as one of the leading experts in subjects relating the decline of bees and the opportunities to overcome this circumstances.
In order to inspire others and share the interesting perspective of professor Goulson, we at BeeLife have transcribed the interview North State Public Radio has performed earlier this year.
You can listen to the original audio from at https://beta.prx.org/stories/250016
Or read the full transcript and learn about Goulson’s fascinating insights below.
What is Dave Goulson's work?
Factors affecting the decline of bumblebees and other bees, have been going on for many years. I am trying to unravel why they are declining, and trying to fix it, trying to make sure that we don't lose any more of them, that they don't continue to decline and that we have a healthy supply of bees in the future.
There is a famous American entomologist called E.A Wilson, and he says that every child goes through a "bug phase", and that he just never grew out of his. I kind of feel the same. I don't know why, but I have always loved the natural world, and particularly insects, of one sort or another. It wasn't just bees but anything that crawled that I could find and put it in a jam jar and keep it in my bedroom window. Actually, my earliest memory of bumblebees is a slightly tragic one. When I was around seven years old, as far as I remember, I discovered some bumblebees that had gotten caught in the rain, and they were sitting draggled on these flowers. I kind of thought I would try and rescue them, so I collected them up, and I took them into the house. I thought I needed to dry them out. So, I popped them on the hot plate of the electric cooker and put it on really low. I even made a little blanket out of tissue paper and put it on top of them. But then, being young, it was one of these cookers that took ages to warm up. I got bored and wandered off, and the next thing I knew there was smoke billowing from the cooker and the poor bees had been frazzled, and that was the end of them. So, my first memory with the bumblebees was not a positive one for the bumblebees. Sometimes I think that I have spent the rest of my career trying to make up for that day.
So, it was this phase which I sort of never grew out of. I think it is worrying that so many teenagers are frightened of insects. We go from being naturally fascinated by creepy crawlers to teenagers that are frightened, thinking that anything that buzzes is going to sting them or bite them or give them a disease. And that is really sad; it obviously does not bode well for the future if we have generations of people growing up frightened and unfamiliar to the natural world.
A growing problematic
I was always interested in the conservation of nature. But, I had lived through a period which was pretty unkind to nature, sadly. By my late teens, I was aware of, for example, hedges being ripped out. When I started walking to school, I had to cross about half a dozen fields. By the time I was in my late teens, it was just one big field. Hedge after hedge had been ripped out and it was all just part of decades of intensification of farming. Such intensification had already started at the beginning of the twentieth century, but it really accelerated during the 60's, 70's and 80's. We moved from a kind of landscape where there were quite a lot of flowers and small fields (there were lots of hay meadows which would produce hay for the livestock, which were full of flowers) into these monocultures of fields with very few hedge areas, lots of pesticides being used, very few weeds. At the same time, we see this dramatic decline in wildlife; not just bees, but birds, butterflies and so on. I was recently involved in a study from Germany, with data collected by German entomologists. They had put "malaise" traps for flying insects. They had set these traps all around Germany from the 1980's, and the daily catch of insects dropped by 76% between 1989 and 2014. That period coincides with my lifetime experience of watching insects or wildlife disappear. I must admit that even having spent a lifetime watching insects, I was shocked by the scale of the decline measured in Germany. Three-quarters of our insects done in just 26 years. And that is after a period when they probably had been declining for many decades. The actual figure is that we very likely have lost a lot more than three-quarters of our insects, and that depresses the hell out of me. It is something that everyone should be talking about and being aware of and doing something to fix.
Getting everyone (or almost everyone) involved
I think the only way we are going to fix this problem is by getting everybody or at least most people engaged. At the moment, still, the majority of the population are not really that interested. They don't care about insects, they probably don't like them very much, they just think they are annoying creatures. But whether they like them or not, people should be aware of just how important they are. But, again, I don't think people are. They might dimly be aware that they pollinate some of their food, but that is just a small part of what insects do. They are at the heart of everything really, of ecosystems, of food chains. So, not only are they responsible for pollinating about 3/4 of our crops and 87% of every wild plant species, but they do a lot of things. They make up the majority of life on earth, they recycle dung and dead trees, leaves and dead animals; they keep the soil healthy as some are predators of crop pests. They are food for so many things, for birds, bats, for grand-dwell of big mammals, for lizards, frogs, and so on. If we really are losing our insects at the speed we seem to be, it is potentially catastrophic. I would argue a length why it is important to look after insects for selfish reasons, because of pollination and all the other things they do. But, actually, the reason I want to look after insects has nothing to do with that. It is because they are cool, beautiful, amazing things. I always feel if I could persuade people to stop for five minutes and get on their hands and knees to look at these things they would realise that.
The bumblebee cleverness and the importance of diversity
I got hooked on studying bumblebees because they are actually really clever. Insects are beautiful and fascinating, but most of them are not the brightest creatures on the planet if we are being honest. Bees are kind of the intellectual giant from the insect world. For example, they have all sorts of tricks that enable them to gather food from flowers very efficiently and effectively, which of course is partly why they are such good pollinators. They can navigate long distances to find patches of flowers and find their way back again without ever getting lost. They can use the sun and the earth's magnetic field as a compass, they can memorise landmarks, they can very quickly learn how to get into really complicated flowers... But there are still tons we don't know about bees.
Honeybees are often the most abundant pollinators species, but they are not always the most effective. In particular, there are some kinds of plants, including some important crops that need to be what is called buzz polluted. The flower needs to be vibrated for the pollen to come out. Their flowers have evolved this rather weird design. The flowers of tomatoes, chili peppers, aubergines and potatoes are examples of plants that require buzz pollination. And honeybees are completely useless for this, they have never worked out how to do it. So, honeybees are completely hopeless for pollinating these plants. Whereas bumblebees and some solitary bee species are really adapted for doing this type of pollination. The bumblebee flies up, bites the flower with its mandibles and shakes up the flower, and then buzzes its flight muscles to shake the whole flower, catching the pollen as it falls. Then, there are other examples such as runner beans, which have really deep flowers, where the nectar is hidden at the end of a tube. In that case, honeybees cannot reach the nectar because they have short tongues. But, some bumblebees have really longue tongues, which reach and pollinate the crop. Basically, different crops tend to be better or worse pollinated by different bees or sometimes hoverflies, or beetles, wasps, etc. The message I always try to get to people is that if we really want a resilient healthy pollination service for all of our crops or wild flowers then we need to look after all of them. Relying on honeybees alone is kind of crazy. Many people mistakenly believe that honeybees pollinate everything. In fact, I feel that a lot of people believe that there is just this one species of bee, that lives in a box and pollinates everything. Of course, it is not true. There are over 20.000 species of bees in the world, that we know of. So, we really should not pin all our hopes on this one species delivering everything.
The case of the almonds is perhaps the most famous example where an entire industry is dependent on honeybees. A very large proportion of the production of almonds comes from California, and it is all dependent on honeybees. It requires almost every hive in the whole of North America, which are shipped for the brief period when the almonds are blooming. And, if anything should happen, if the honeybee population should fall much further, imagine a disease outbreak (we are all aware that honeybees have had lots of health problems in recent years), the almond crop would fail. That would obviously be catastrophic for almond growers. It seems to me that we ought to have a backup plan, and that plan is looking after the wild bees, which has not been going on so well until now.
I think the biggest threat to wild insect population is the way we have chosen to grow food. That is a rather sweeping statement. As with the almonds in California, we have gone down this route of huge monoculture cropping, which at a time became more and more reliant on lots of chemical inputs as pesticides. We managed to, essentially, create huge monocultures with very few weeds. As with the almonds, there is nothing underneath them, when they stop blooming there is nothing there to live on. There are no flowers nor leaves. Unless you are a pest of almonds, there is nothing for you. The same is true with a huge proportion of the world now. Under wheat, canola, or whatever it might be, we have essentially made big chunks of the world hostile to more or less all forms of life apart from the crop or pests of the crop. Of course, we need to feed people. But, I personally question if we are doing it the right way. If we are doing it in a sustainable way, or whether the price of the way we are doing it is just too high. I think there are alternatives that we should be seriously investigating.
Currently, there are three issues that bees face. One of them is indirectly linked with farming, which is diseases. We have accidentally moved around diseases around the world for centuries. With honeybees primarily because they are good pollinators and we like their honey. We brought them to the Americas (they are not native to the Americas or, Australia or New Zealand), they actually came from Eastern Europe. But now they are a global species. Unfortunately, when we moved them, we took a bunch of bee diseases with them, including viruses, varroa mite, bacterial and fungal diseases. The problem with that is that wild bees naturally have a whole range of diseases, but they tend to be diseases they have encountered for a long time (thousands or millions of years), so they have developed a resistance. But if a new disease is brought to the Americas, or wherever, that could be devastating in its effects. We know, for example, that there is a type of Asian bee diarrhea, which is now all over the world, and can be really harmful to wild bees like bumblebees.
The other two issues are much more general. One is that we have lost most flowers. We have simplified the landscape enormously. If you are a bee, you need flowers. As in the case of social bees like bumblebees, you need flowers right through the season. So, you need a nice continuity, a diversity of flowers to keep them going. The modern world is sadly lacking in flowers. But then, when the bees do find a little patch of flowers somewhere or a flowering crop like canola, there is a very good chance that it is contaminated with pesticides. This is something that my research team has been studying in Sussex and it is pretty alarming. If you ask a farmer a list of the pesticides that they apply to each field, it is a long list. The fields around here where I am sitting are being treated with maybe 20 different pesticides each year. These is normal practice. These are not bad farmers at all, they are just doing what everyone else does, following the advice of their agronomist. That includes a whole range of insecticides, herbicides, fungicides, molluscicides. If you are a bee, foraging in farmland, you are encountering a whole range of pesticides year-round. People have sampled honey and pollen from bee nests and analysed it for pesticides and it is actually jam full.
There is this one particular group of pesticides which are major cause of concern because they are highly toxic for bees, which are the neonicotinoids. A group of insecticides that were developed and introduced in the mid-1990’s and they had become the biggest selling insecticides in the world. They are neurotoxins that attack the brain of the bee. And they are systemic chemicals, so they are applied to crops and spread through the crop protecting it from any kind of pest, which is attractive from a farmer perspective. But, the downside is, if it is a flowering crop, they are going to the pollen and nectar, then bees get poisoned. More recently it has emerged that there are commonly found in wild flowers growing at the edges of fields. Which is really concerning because we encourage farmers these days to put in flowering plants in the edge of the fields to try to encourage pollinators. But, sadly, these chemicals, neonicotinoids, contaminate the soil and are soaked up by the roots of wild flowers and are contaminated that way.
There was a recent study where they got honey samples from around the world. Literally, every continent, most countries, and analysed them for neonicotinoids. In 75% of honey samples, globally, contain these neurotoxins that kill bees. That ought to be really alarming for everybody.
Their toxicity is normally measured as the LD50 which stands for the lethal dose that kills 50% of your test animals, and the honeybee is a standard test animal for pesticides. So, the LD50 for the most commonly used neonicotinoids is about a fourth billion of a gram per bee, which is obviously not very much. To put that in context, that means that one teaspoon of these chemicals is enough to kill one and a quarter billion honeybees. Just in the UK, we use about 110.000 kilos of these chemicals. Certainly enough to kill every bee in the planet several times over. We know that they are very toxic, and we know that they are in the bees’ food. There is also a lot of research showing that the concentrations in the bees’ food are enough to harm them. As well as higher doses killing the poor bees, slightly lower doses, “sublethal doses”, as they are known, reduce the lifespan of the queens, as their egg laying. They mess up the immune system of the bees and their navigation, so they get lost when they are out foraging. Remember, these attack the brain of the poor bee. As I explained earlier, bees are really clever and rely on that cleverness to survive. Unfortunately, these chemicals knock that out. There is really good evidence that these things are harmful not just to bees but to any insect. And, as a result, the European Union decided to ban most of these chemicals, the three more widely used versions of neonicotinoids. As of the end of 2018, they will be banned in Europe, which is fantastic. But, you guys (United States) have still got them and there is no sign at all that any of the US will take any steps to regulate the use of those chemicals. In fact, the State of Ontario, Canada, is really the only place outside of Europe that is doing anything about this. That is bad news and there are tons of these chemicals being used in developing countries as well, including tropical countries where there is huge insect biodiversity. It breaks my heart to think what is being wiped out. But then, even in Europe, new chemicals are coming on to the market which look quite similar. I suspect they might turn out to be just as harmful.
Have we not learned the lesson?
If you look at the history of pesticide use since the 1940’s, when synthetic pesticides were introduced, we just seem to be going round and round in circles. We bring a new type of chemical, then 20 or 30 years later, it emerges that they are really harmful to the environment or to people or whatever, then they get banned, so we have the organic chlorides like DDT, phosphates, we have the carbonates (which most people have not heard of) and then we have the neonicotinoids. But we don’t seem to learn any lessons from this, which kind of drives me nuts. At what point are we going to think “Hang on a minute. Maybe we should be looking for another solution which is not a pesticide, that is not a chemical that kills all insects”. That seems to me long overdue. But, unfortunately, the mindset of most farmers today (not blaming the farmers, they are just following advice), but they have been brought up using pesticides, and seeing them as the solution. So, if you ban one pesticide, they want to know what you can sell to replace it with. We were also told they neonicotinoids are quite short lived, but it took a very long time to realise that they were actually accumulating in soils and leeching into the streams and rivers. And, in the same way, we were told that glyphosate degraded as soon as it touched the soil and many of us naively went with that. Clearly, we now know it is not true. It seems to be, in some circumstances, quite persistent. There is good evidence that there is plenty of glyphosate in human food. In a German study, they could detect glyphosate in the urine of around 98% of Germans tested. Quite a lot of them were urinating glyphosate concentrations higher than the legal limit in streams and rivers.
You can help
It is quite easy to make your garden bee-friendly, or just life-friendly. There is a really simple starting point. I have a YouTube channel where I point at all the flowers that are good for bees. Basically, traditional cottage garden flowers tend to be pretty good. Lots of herbs, thinks like lavender, rosemary and thyme are fantastic for bees. So, grow bee-friendly flowers, don’t mown your lawn so often. People think that a lawn is pure grass but it if you stop cutting it, flowers spring up. Don’t use any pesticides in your garden. That is a really simple one. You don’t need pesticides in your garden setting. Whether or not we need them in farmland is a good debate to have, but I have a big garden and still being busy with a full-time job I still manage to grow lots of fruits and vegetables, as well as pretty flowers without using any pesticides. Any damn fool can do it, it is not very complicated. If you have got a few aphids, leave them. I almost guarantee that a ladybird or a hoverfly will come along them and eat them. Bee hotels are also a really effective way to encourage bees in your garden, and they are really fun for children to watch. It is really just a bunch of holes in a piece of wood or a bundled in some sort of bamboo. If we can get enough people on board, to make all of our gardens wildlife-friendly, as well as all of our parks and road bridges and roundabouts, then basically our entire cities would have turned into these vast nature reserves, which would be really cool.