Working in Entomology

Professor Michael Majerus talks to Rachel McLeod

Complete transcript

Rachel and Mike in front of a breeding cage containing Heliconius butterflies

I chose to interview Mike Majerus because he is the President of the AES and he also does lots of work on butterflies and ladybirds. The current experiment he is doing on ladybirds is collecting lots of pupae and then letting them hatch and keeping a total of how many harlequins hatch and how many 2-spots hatch. Harlequin ladybirds are foreign, they were introduced into other countries to try to control aphid numbers and have somehow travelled to England . They are doing extremely well, much better than the native species. To find out more about the harlequin ladybird invasion you can look at the website http://www.harlequin-survey.org.

harlequin ladybirds overwintering

The main reason the pupae don’t hatch is the scuttle fly that specialises in laying its eggs in the pupae of ladybirds. They have discovered that the flies don’t like harlequin ladybirds, but they are gradually starting to use them more. The scuttle fly will always choose the bigger pupae, but not if it is a harlequin, even though they are bigger than the 2-spot ladybirds and most other ladybird species. Over a period of 5 years there has been a change between no harlequin being attacked by scuttle flies to 3 in every 50. Mike is trying to find out a reason why the scuttle flies don’t tend to lay their eggs inside harlequin chrysalises.

He is President, I think, mainly because he is an experienced entomologist who knows what he is talking about, and a good communicator. He is also a professor at the University of Cambridge .

What insects do you keep?

Here? We have mainly ladybirds, and we have an awful lot of ladybirds; so we breed greenfly, specifically because that’s what the ladybirds feed on, and we also have some butterflies and moths. The moths tend to be British, and we work on what’s called melanism, these are the moths that turned black or darker after the Industrial Revolution, as a consequence of pollution. They’re now going back the other way. So most of the moths are British, but the butterflies are mainly from the tropics, either from East Africa – we work on a genus of butterflies called the Acareas, and then we also have butterflies here from Central and South America – these are mimetic butterflies and the genus is called Heliconius.

harvested ladybirds with aphids in the foreground

If you were to keep only one insect, which would it be and why?

If I had to keep only one insect? Oh, goodness. I think the thing I would choose would be the Indian Moon Moth, and there’s a reason for this: when I was a kid, I used to go along to the AES exhibition, which was at the beginning of October, always the first Saturday of October, and this in those days was more in the centre of London, Holland Park, places like that, and I used to be able to buy the caterpillars of the Indian Moon Moth when they were very small, and they’re little sort of bumpy red caterpillars when they’re very small, they turn bright green later, and they feed on rhododendron, so they were quite easy to breed and the nice thing was, because rhododendron is an evergreen, you could breed them throughout the year, and if you bought them at the beginning of October they would hatch just before Christmas, and then these beautiful, pale green, big-tailed moths, absolutely fabulous moths, I used to put them on our Christmas decorations, alive, every year. And it was great. As long as you left the light on in the room, they wouldn’t fly. And then of course I would take them away, when we had some males and females I would take them away and put them in a cage elsewhere, where there was an airflow so they would mate and lay me more eggs. But that, I think … I would hate it if you made me have only one insect, but if it had to be, I think I would go for the Indian Moon Moth.

Indian Moon Moth

What is your favourite place to go field collecting?

Oh, that depends what sort of mood I’m in. If I’m in a ladybird mood, I think it would be Chobham Common in Surrey , which has got lots and lots of great ladybirds. We’ve found three quarters of the British ladybirds on just that one site, which is pretty amazing. But if I was in a butterfly mood, it would have to be South America, somewhere like, well, somewhere on the eastern side of the Andes in Ecuador . It’s staggering – you can walk down into a montane rainforest there and you just never want to leave. You just see new things, amazing things, you go from the big Morpho butterflies, these bright iridescent blue butterflies to tiny, tiny little skippers flitting around, and then the little blue lycaenids feeding in little clusters on minerals coming out of the seepage coming out of the rock, that sort of thing. And it’s just the most fabulous place in the entire world, as far as I’m concerned. And there are more species of butterfly in South America than in the rest of the whole world put together. So you’ve got this amazing diversity, where you still find decent rainforest. Of course, much of that gradually is being cut down, and that makes me very sad.

How did you get involved in entomology?

I don’t know. I don’t remember. I was four. My mother told me that I was four when I caught my first butterfly, with my hands. She told me it was a Red Admiral. I don’t know why I did it, and that’s 50 years ago now, and I don’t remember any time not having been just fascinated by insects. And so I can’t really … it’s just something … my parents weren’t particularly into insects, and neither of my brothers is – it’s just something that must have caught my attention when I was very small, and triggered it, and so I’ve never not been.

What’s the most exciting thing you’ve done?

In an entomological sense … the most exciting thing I’ve done. Well, I guess two or three. If I go back to when I was a kid, the first time I went to the British Natural History Museum in South Kensington and went into the entomological section, that’s not the bit open to the public, that’s the collections that are kept for research at the back. That was stunning. I mean that was just staggering. I just did not … I was like most kids in a candy store, this was just the greatest place on Earth, and to me to a large extent it still is – I just adore going down there, it’s absolutely fabulous. I guess also, because I’ve been very lucky with my entomology, I meet some really interesting people, people like David Attenborough and Bill Oddie and David Bellamy and so on. And that’s always exciting, it’s always really nice to meet these amazing naturalists and biologists. But I think probably there is nothing more exciting than flying off somewhere to the tropics and the first day you walk into a tropical jungle that you’ve not been to before. That really is … you know, it’s not the one most exciting because every time it is just fabulous, you know, I can feel my heart beating as I go off, I’ve got my net and I’ve got my stick, and what am I going to find? It’s that sort of feeling. I love it!

What do you think is the best way to get people involved in entomology?

Talk to them! Talk to them, show them things, tell them how fabulous these things are, how important they are. Some of them are pests, but, you know, if you took away the bees, we wouldn’t have any flowers, or, we wouldn’t have any pretty flowers. Very few. There are a few that are bat-pollinated or bird-pollinated, but bees are so important in pollinating stuff, and we wouldn’t have fruit. There’s so many things we wouldn’t have – if you took the insects away, we would lose most of our birds. Some birds feed on seeds, but the majority of birds feed on invertebrates. You know, if you just think about your garden, the blue tits, the great tits, the robins, the wrens and so on – these are eating insects. That’s what they feed their young, that’s what they need themselves, so the swallows and swifts and so on, flying through the sky… So explain to people, tell them – for example, most people think that moths are nasty because they eat clothes, explain to them that of the over 2,000 species of moth in this country, you can count the number that are likely to eat your clothes, and it’s actually the caterpillars that do that, on the fingers of one hand. And they are all tiny little things anyway. So the moths that they see coming to the lights in the bedroom and so on, these are not clothes moths. These are just good moths and they should leave them alone, not kill them, put them out of the window if they don’t particularly like them, but explain things to people properly. The science for most things is not that hard, and if people really understand about insects, then okay, there’s one or two that you would rather do without – so I know you are fascinated by cockroaches. I don’t want cockroaches in my pantry. I’ve seen interesting cockroaches in Madagascar and places like that, I like cockroaches, but I don’t want them in my food. There are other things I would rather keep out of my food, things like flour beetles, but the vast majority of insects do no damage and they are an incredibly important part of our natural ecosystems, and without them we’d be really stymied. We’d be in a real mess. So that’s the sort of thing I’d explain, and I’d show them some of the beautiful things, some of the more spectacular insects, and try and explain. We do a lot of work on ladybirds. Most people like ladybirds, so you can use ladybirds to teach a whole range of biological things, from genetics to the way evolution works to interactions between a predator and its prey, that sort of thing. You can use the insects that they like, things like ladybirds, to explain the principles of biology.

Why is entomology important to you?

Well, it’s really the reasons I’ve just said – because I think it should be important to everyone. We face incredible problems with the world, whether you’re talking about global warming or pollution or loss of biodiversity, or there just being too many people. All these things will have an impact on insects, and because insects are such an integral part of ecosystems, eventually it will come back and have an impact on us. And this is the case whether you’re talking about … Let’s take one example, let’s take mosquitoes. We need to understand mosquitoes because they vector, they carry, lots of diseases and particularly, the famous one of course is malaria. We don’t have malaria now in this country. But if temperatures increase through global warming, we are likely to get malaria back in this country, because we will get the mosquitoes that carry it, back in this country. Now I know this because I was in East Africa, in Tanzania, a couple of months ago, and one of the people I was with was a Portuguese man who works on the mosquitoes that are coming into Portugal now, as temperatures rise, carrying malaria. Portugal is not that far south of here, so in 30, 40 or 50 years if temperatures continue to rise as they are, we are going to have malaria back here. We need to understand the role of insects in ecosystems as a whole if we’re going to make sensible decisions about our future and the future of this planet.

What parts of entomology do you not like?

Oh, I’m not sure there are any parts I really don’t like. One of the options when I was about 18 was to think of doing a university course on applied entomology, and this was back in the early 1970s. I looked at what applied entomology really was, and it seemed to be how you most effectively kill insects. So, this was with the use of insecticides and so on. And that part I’m not so interested in. I realise that for many people this is a very important area of entomology, but I do sometimes think that the people who spend their professional lives trying to kill insects – the pest controllers – they sometimes rather ignore the evolution and ecology and genetics and the rest of the insects’ lives. They don’t really get to know their organism very well. All they care about is stopping it living, rather than being interested in the insect’s life. And that sort of … the entomologists who are like that – not all biological controllers are like that, some are very, very good natural history entomologists – but the ones who really just focus on killing and don’t really take the trouble to find out about the things that they are trying to kill, I’m not sure I get on very well with. And so it’s that part of entomology that is the only one I would say that I don’t like.

Are you scared of any arthropods?

Scared of? No. There are one or two I don’t like in my home, and there are one or two that I will go quite a long way to try and avoid, that is, take precautions. So if I’m walking through the jungle in South East Asia or Northern Australia I will have quite thick jeans on, with my socks up over the jeans, and I will wear elasticated shirt cuffs and so on, and make sure everything fits tightly around with a belt, and the reason I do that is I don’t like getting bitten by leeches too much. There’s nothing wrong with it, they don’t hurt. It leaves you bleeding for a long time, because they actually put in a chemical that stops your blood clotting, and so on, so you get very bloody socks if one gets in. But I would rather not be bitten. Leeches don’t carry disease, so they’re actually not too bad. Some ticks and some mites do, so those I’m also very keen to avoid. And there are typical things, I don’t particularly like horseflies, because I react quite badly when horseflies bite me, but I wouldn’t say I really … I’m certainly not scared of them. I’ll flick them away if I see them.

What’s the most embarrassing thing that’s happened to you?

Well, okay, I’ll tell you this, but I’m not sure I should for the Bug’s Life magazine. You’ll have to write this very carefully, Rachel.

So, this was in Panama . It could have been incredibly embarrassing. Fortunately I was entirely on my own. There was a particular plant that some of my Heliconius butterflies feed on – they come to take the nectar. And I wanted a photograph of this, and I was on the Dividing Range that goes from the Rockies all the way down to the Andes . I was on a path there and I found this absolutely perfect flower that was just at the right stage for a photograph. So I got my camera out of my rucksack, set up, and it’s a nice macro lens on it, that you sort of have to move, and I was just about ready to take the picture when I felt a bite on my leg, a little bit below the knee, and then another one. And so I looked down, and very stupidly I was standing on a trail of army ants, which had been going straight up my boot, and then up my trouser leg, and they were biting. And they bite pretty hard, this particular one. And I reckon it was about 30 seconds before I’d stepped just one metre to the side, because then you’re off the trail, and to when I had no clothes on at all. At which point I could shake all my clothes, you know, first get the ants off me, and then shake all my clothes and get dressed again. That’s why I say I’m really glad there was no-one else there, because if there had been it would have been stunningly embarrassing. But even then I kind of felt, ‘Oh God, this is a bit crazy’. And ever since then, whenever I’ve set up to take a picture I always just check what I’m treading on. I got about 100 bites, so it was quite a painful lesson to learn.

What is your favourite thing to do in your job?

My favourite thing I’m afraid is still, and it will always be, being on a path in a tropical jungle, usually on my own, just doing what I do best. But other than that, talking. Actually now, as I get older and grumpier and more worried about the future of the world, I talk more and more, and I say more and more controversial things. I get very annoyed at people who don’t take any notice of the trouble that my generation and the generations before have got this Earth into – into the problems of global warming and pollution and so on. And when I see people not recycling properly, when it takes nothing to recycle, I mean, it’s so easy to do. That sort of thing. Or when I hear governments saying, ‘Oh, we should go to biofuels,’ and then I see tropical jungles being cut down to plant oil palm as a biofuel crop – I mean this is just idiocy, this is just stupidity. And I actually now get a considerable amount of pleasure and excitement simply at talking to people about these issues and trying to make a difference, trying to get people to understand that they are really going to have to do something about it, otherwise the next two or three generations are in huge problems, and may not survive.

What do you think would happen to insect populations if we suddenly disappeared off the Earth?

If the humans all disappeared, I think there would be a period when insects would show quite rapid changes still, because if we disappeared tomorrow, then the things that we have caused, many of them, will not stop immediately. They will take time. We will also then get some quite interesting new environments, new niches. So, what will London be like, for example, if there are no humans? If you think about London, the buildings will start to decay, and the plants will grow and the trees will grow. And then if you think about what plants and trees are there, well actually London has got a hugely diverse flora. There’s a tremendous number of species, most of which are in people’s gardens, or in parks, or places like Kew Gardens, and are not British, they’re foreign. And some of these will just die without care, but many of them will survive, and so you’ll get the native insects gradually being able to use those, or species coming from further south, because global warming will continue. I think there will be a huge change, but gradually – it may take a hundred, 200, 300 years – things will stabilise down and we’ll get into a more balanced ecosystem than the one we’re in at the moment, which is very rapidly changing because of what we’re doing. So take us away and eventually things will settle down again.

What have you contributed yourself to entomology?

Oh, that’s a question I really don’t think I should answer. I should let other people answer that. There are one or two things that I’m known for. I do work on the causes and consequences of female-biased sex ratios in ladybirds and butterflies, and I think I’m well known for that. I’ve done quite a lot of work on industrial melanism in moths, particularly the Peppered Moth, and I’m very well known for that. And there are people who don’t believe in evolution who seem to get very cross with me, and they say very nasty things about me on the worldwide web. I don’t mind that because I know my science is good science, and just because I don’t happen to be finding out things that they believe, that’s their problem, not mine. I think I’m also a little bit known for wanting to enthuse other people with insects, with entomology, and doing things like nationwide ladybird surveys. We’re doing the Harlequin and the UK ladybird surveys at the moment. This is the second go I’ve had at doing things like this, because I ran another one from 1984 to 1994. And there are many professional entomologists that aren’t still members of the AES, the Amateur Entomological Society. I don’t know why. I started with the AES, and I still write for the bulletin and for the Bug Club magazine and so on, because I actually want to say that if you’re interested in bugs, if you’re interested in insects, you can make a living out of it. You know, you have to work hard, I won’t say it’s not a lot of hard work, but actually I’ve had the most fabulous life because of insects, and I think other people should do that as well. So maybe I’m known for being very enthusiastic about insects.

What is the important question I should have asked you?

Oh, I don’t know, Rachel. I think you have asked me lots of very, very important questions, and one or two that were curve balls, and … I don’t know – what’s the most important question you could have asked me? You could have asked, ‘What is so special about the year when this article is likely to come out?’ – which is probably, by the time you’ve written it, it’ll come out next year. So you could have asked, ‘What is so special about 2009?’ Would you like to ask that? Because the answer is – next year it’s 200 years since the birth of Charles Darwin, who gave us the theory of evolution, and it’s 150 years since the publication of his great book, The Origin of Species. And I think next year the AES and all sorts of other people – the BBC, The Natural History Museum, Sir David Attenborough, and so on – they’re all doing things focussing on Charles Darwin and the theory of evolution, and how important it is to our understanding of ourselves and the Earth that we live on. So there’s another question you might have asked.