Rachel McLeod interviews Seirian Sumner, Research Fellow, ZSL.



Seirian and me by the sign for ZSL


I met Seirian at the Zoological Society of London, which is a conservation organisation on zoology.   I found out about Seirian because Iím particularly interested in social insects.  Learning about sociability and learning about evolution go together as we need to know about how sociality evolved.  Paper wasps have evolved the drifting pattern (workers helping at different nests) and they are at the very beginning of being social, so we can understand more about sociability by studying them.


Wasps and other social insects are so important because there are so many of them Ė their biomass (the mass of living biological organism) is absolutely huge.  One chart compares the number of social species with solitary species and the other shows what the biomass of social and solitary insects.  There are very few social species compared to their biomass which means that they are doing very well.




Species compared to biomass

Source for data: Edward O Wilson Journey to the Ants


Seirian works on social paper wasps, and at the moment she is radio tagging them.  These tags are pet microchips but without the glass capsule.  They are super-glued to the waspsí thorax.  This means that she can tell where each wasp has gone, and because of this she has discovered nest drifting, where the workers help out at many nests.  Over 800 wasps were tagged.  She found this out in Panama, which is in between North and South America.


A photograph of a tagged wasp (photo © Aidan Weatherill)


Look at my website, www.rachelmcleod.com/interviews to see the full transcript of this interview.  You can also listen to it.



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


It would have to be the paper wasp Iím very fond of the paper wasp. Once you understand its behaviour, then itís not at all aggressive, and you can get on very nicely with it indeed. But I personally find them very interesting because they are a primitive eusocial insect, which means that they are at the very beginning of the eusocial spectrum, changing from a solitary to a social animal, which is very exciting for somebody like me.


What is your favourite place to do field collecting and why?


Well, most of my field workís been done in Panama recently, so I guess it would have to be my favourite place. There are lots and lots of paper wasps there, and the paper wasps in Panama, in the tropics, are much bigger than the wasps you get in Europe, and they build much bigger aggregations of nests, which are fantastic for entomologists like me who want to study lots and lots of nests all at once with very little effort.


A paper wasp nest



What was your favourite trip?


Iíve just returned from the field about a month ago, and I must say it was a very successful trip, so I think it must be my favourite one. We had actually too many wasps, we had too many wasps to tag, we were radio tagging them, they were everywhere and they were very friendly and none of us got stung, so it was a particularly nice trip.



What is the most exciting thing youíve done?


I think it has to be my radio tagging. So Iíve been putting these little radio transmitters onto wasps to monitor their movement between different nests.


A tag


Using those we can follow the movements of wasps between different nests, and by doing that weíve discovered that they visit lots of different nests, which we didnít think they did before, and weíve revealed a whole new behaviour called drifting behaviour, and we think that they drift between different nests in order to help raise the brood on lots of different nests that theyíre related to.



So, how social are different types of insect?


In all the ants you have a queen, and you have the workers, or you have several queens and you have the workers. And the workers cannot become a queen. They canít lay eggs; they canít lay fertilised female eggs. And so we call those advanced social insects, theyíre highly derived, highly evolved. And the honey bee comes under that category as well. But these wasps, these Polistes wasps, are primitively eusocial, which means that theyíre only at the beginning of life as a social animal, so theyíre very interesting to study if youíre interested in evolution and sociality and how things went from being solitary to social, because theyíre kind of bridging the gap between the two. So the reason we know theyíre primitively social is because any female that emerges from the nest can become a queen. So when a female emerges from one of these cells, a pupal cell, she can start life off as a worker, or she can later on become a queen, or she could remain as a worker all her life, or she could go off and found a new colony as a queen, or a worker on that nest. So, itís a very flexible life strategy. And this is how sociality first started, with these flexible, plastic, we call them plastic castes, theyíre behavioural castes, theyíre only determined by their behaviour rather than anything physiological or morphological.



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


To get interested in collecting whatever insect they come across. If they happen to come across a bee on their windowsill, have a good look at it, and then maybe work out what it is, look it up on the internet, and learn about the wonderful life of insects and how interesting they are.


What does my generation need to do in terms of entomology?


Thereís lots of new molecular techniques that are now becoming accessible for all kinds of entomologists. So weíre able to study behaviour now at the level of the genes, and until very recently that could only be done in what we call Ďmodel organismsí, like the fruit fly drosophila you might have heard of, and other lab organisms, but now weíre able to look at the genesí underlying behaviours in all sorts of different insects. They donít have to be in the lab, they can be in the field.


What parts of entomology do you not like?


A: I donít like getting stung.  My wasps have a very big sting, and I react quite badly now. I swell up like a balloon if I get stung. But I take precautions not to get stung now. I wear bee hats and big gloves and stuff. I donít think thereís any other aspect of entomology that I donít like. I think entomologyís a great thing to study because you can have so many study organisms in one tiny little place, making it possible to do all sorts of experiments very easily, whereas if you try to do the same thing on mammals, for instance, it would be much more difficult to have the sample sizes that you need.


Whatís the most expensive piece of equipment you have bought for a trip, and why?


Well, equipment for molecular work is always very, very expensive, and my lab has purchased very expensive pieces of equipment that we needed to analyse the genes. I guess an example might be a real-time PCR machine, which costs around £25,000. A real-time PCR machine enables us to amplify different parts of DNA and to look at the expression of those genes in individual wasps, or individual wasp brains is what I do, or you can look at them in different parts of the body.


Are you scared of any arthropods?


The only thing Iím marginally near-scared of are the yellow-jacket wasps that you get in this country. I really donít like them. And people always laugh because they think that Iím the wasp woman, I work on wasps, thatís my life, but I really, really hate the yellow-jacket wasps you get here, because they chase you while youíre having your ice creams or your dinner in the summer and theyíre just really nasty and unpredictable.


Whatís the most embarrassing thing thatís happened to you?


I got stung on my eye once, and it ballooned up and I looked like Elephant Man, and that evening I had to go and meet an important scientist and it was very embarrassing because I looked horrendous with this huge blown-up face. I guess thatís probably the most embarrassing thing thatís happened to me.



What do you spend most of your time doing?


I spend most of my time doing administration, at the moment. Filling in forms for students, for people to come and work with me. Doing ethics forms, because believe it or not we have to do ethics forms for tagging insects. Even cockroaches need an ethics form. I guess the rest of my time Iím writing grants to get money in to do more research, and any time thatís left over Iím writing papers or supervising projects.


Whatís your favourite thing to do in your job?


Oh, I love the field work. Thatís when you really get to know your organism, and thereís nothing better than being in your organismís natural environment and seeing, observing its behaviour, actually sitting and watching what it does. And thatís when all the ideas come to you, because you realise things that you canít realise when youíre just reading a book or youíre just analysing numbers on a screen. So definitely the field work.


How do you become an entomologist in your sort of job?


You have to do a degree first, and then you have to do a PhD, and then you just take it from there. You start doing a Postdoc after that, where you work on somebody elseís project. So the PhD is normally your own project that you work on,  And then after that, well what I did after that is I got fellowships, which allowed me to set up my own independent research projects, and then it just kind of builds from there.


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


I think the insects would mostly do very well, except for the invasive ones. So there are many species that weíve helped by carrying them around the world, introducing them to new countries where they havenít got any natural predators, and then thereís nothing to check their populations, to keep the populations down, and they just explode into these huge, huge populations, and they cause immense ecological damage. So I think that would be a good thing, actually, if that was stopped.


What have you contributed yourself to entomology?


Well, Iíve contributed in my studies on social evolution. Iíve shown that the genes underlying queen and worker behaviours in paper wasps are different, so if youíre a queen you express different genes to those when youíre a worker. Iíve also revealed this exciting behaviour of nest drifting, where the wasps seem to help on multiple different nests. Previously I used to work on leaf-cutting ants, and I did a little body of work on a social parasite of the leaf-cutters, which was very under-studied, and that social parasite is at the very beginnings of becoming a good parasite, an obligate parasite.


Some Polistes wasps on their nest


What is your opinion on entomology being viewed as rather masculine?


When you first became interested in insects and you heard about entomology, did you think an entomologist would be in a museum, with musty cabinets full of dead insects, and a big beard? Thatís how I imagine an entomologist. So I guess it can be viewed as masculine. But maybe itís more that the sciences in general are viewed as a more masculine topic. But I think thatís changing, very much so, definitely, with my generation and generations coming after me, there are a lot more females in science and entomology, and I think thatís a very good thing.


Whatís the most important question I could have asked you?


I think you could have asked me Ďwhy are social insects so interestingí, as opposed to any other insects.  Well, I think social insects are so much more interesting than solitary insects because theyíre a whole new level of complexity. Solitary insects that live on their own, they have possibly a very interesting life cycle and biology, but itís just that individual on its own, and it doesnít have any complications around it, except for its ecosystem, obviously. But in social insects, youíve got that extra level of complexity, so youíve got the interactions of that one individual with maybe ten, fifty, a hundred, thousand, even a million other individuals, so I think thatís fascinating, and itís much more of a challenge to understand why and how those animals evolved. Also social insects are incredibly successful. I canít remember the actual facts, but I think that ants represent a quarter of the insect biomass in the world, or something like that, so they really are a key species for any ecosystem, and they form enormous colonies, and Iím just fascinated by the way that one colony can function with so many different individuals. So I think social animals in general add a whole new layer of complexity that is really exciting to study as an entomologist.