Interview with a social insect scientist: Madeleine Beekman

Madeleine in the field

Madeleine in the field.

IS: Who are you and what do you do?

MB: My name is Madeleine Beekman and I study how insect colonies are organised and the ways by which they deal with conflict within their societies. I have done quite a bit of work on foraging behaviour in mass recruiting ants and honey bees as well as nest-site selection in different species of Apis. Currently I continue to work on the amazing Cape honey bee, a subspecies of honey bee in which the workers are capable of cloning themselves. Workers can now produce females instead of males, which completely changes the relatedness within the colony. This change in relatedness in turn leads to very interesting conflicts not usually seen in other honey bees. More recent is my adventure into honey bee virus land. Here the aim is to unravel how honey bee RNA viruses become more virulent and what role exactly the ectoparasite Varroa destructor plays.

IS: How did you end up researching social insects?

MB: While doing my MSc at the University of Amsterdam, people were trying to commercialise the use of bumble bees in glasshouse pollination, particularly of tomato crops. Tomatoes are a funny crop; the plants continuesly produce flowers which can pollinate themselves, but the pollen needs to be actively loosened. When grown outside, the wind does the trick, but not in glasshouses. For a long time every tomato plant had to be touched daily with a vibrating stick to ensure pollination. Enter honey bees….they are much more efficient and cheaper. But honey bees are also picky, so as soon as there are nice plants in flower outside, honey bees ignore the tomato crop (remember they have a very useful communication dance, so only a few workers need to find something better and soon the whole colony knows about it). Obviously glasshouse growers could have screened their glasshouse, but there are other disadvantages to honey bees. Their colonies are large, they poo a lot and they can sting. The bumblebee Bombus terrestris started to look like an interesting alternative. The problem was that bumble bees are annual insects, and tomatoes are grown almost year round. What they needed was a PhD student who was going to figure out how to prevent bumble bee queens from going into diapause, how best to survive artificial diapause, and how to obtain good quality colonies year round. That PhD student was me. I was already obsessed with insects and mites, was an amateur beekeeper and loved the challenge.

IS: What is your favourite social insect and why?

MB: That is a tough question….I think I will settle for the blue-banded bee Amegilla cingulate. It is simply gorgeous and the males have this funny habit of forming social roosts (to be honest the blue-banded bee is not the only one in which the males hang out together at night, but they are the blue-est…).

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Roosting blue-banded bee. Photo: James Niland/flickr

IS: What is the best moment/discovery in your research so far? What made it so memorable?

MB: I think the most memorable occasion was when I got to work one morning and my then Honours student Alex Jordan said to me: ‘I think I found something really cool’ (or words to that effect; it has been a while). Alex had spent a field season in South Africa working on the Cape honey bee and was analysing his data. When I excitedly asked what that might be, he replied by saying he wasn’t going to tell me until he was certain. Turned out he found that workers of the Cape honey bee parasitise queen cells of other honey bee colonies on a massive scale, a discovery that changed the direction of the research on the lab on this weird bee. Because these workers produce clones, they reincarnate themselves in genetical terms.

IS: If teaching is part of your work, what courses do you teach? Has your work on social insects helped to shape your teaching?

MB: I teach in a first year unit called Life and Evolution, and in two third year units: Animal Behaviour and Evolution and Biodiversity. In my teaching I am foremost an evolutionary biologist. I do give examples of my own work where relevant, and obviously social insects are ideal if you want to impress first year students, but I am careful in pushing it too far.

IS: What is the last book you read? Would you recommend it? Why or why not?

MB: ‘A little life’ by Hanua Yanagihara. One of the most beautiful books I have read, so I most certainly recommened. Science-wise, the last book I read was Frans de Waal’s latest book: ‘Are we smart enough to know how smart animals are?’, also highly recommended as it makes us think about what exactly intelligence is. I look forward to reading Peter Godrey-Smith’s latest book ‘Other minds: the octopus and the evolution of intelligent life’ (see a pattern here?) and Menno Schilthuizen’s upcoming ‘Darwin comes to town: how the urban jungle drives evolution’ (so many books, so little time….).

IS: Did any one book have a major influence in shaping your career? What was the book and how did it affect you?

MB: Boring anwer I fear, but that must be Richard Dawkin’s ‘The selfish gene’ and ‘The extended phenotype’. Not very original, I know, but they are extremely influential books.

IS: Outside of science, what are your favourite activities, hobbies or sports?

MB: I would love to spend more time reading books, both science and fiction. But I also love exercising and horse riding. My main form of exercise is RPM, where you get on a stationary bike and go nowhere but end up completely exhausted after 45 minutes because there is a trainer shouting instructions such as ‘go faster’, ‘put more gears on’ or (my favourite) ‘suck it up’. I also spend (too little) time on a yoga mat.

IS: How do you keep going when things get tough?

MB: I exercise or get on a horse.

IS: If you were to go live on an uninhabited island and could only bring three things, what would you bring? Why?

MB: Sunscreen, because I would only go to a tropical island. This is cheating I suspect, but a huge bookchest full of books. And my husband, as I’ll get lonely after a while (and we can swap books if he also takes a book chest….).

IS: Who do you think has had the greatest influence on your science career?

MB: Different people at different stages in my career, but I can easily single out two. Foremost my PhD supervisor Maus Sabelis, who sadly died too young. He taught me to believe in myself. And ever since I moved to Australia Ben Oldroyd, life partner and close colleague. Without his support I wouldn’t be where I am now.

IS: What advice would you give to a young person hoping to be a social insect researcher in the future?

MB: I think these days young researchers need to be much more strategic than I have been. Obviously doing good science is essential, but you also need to make sure people know who you are and what you do. So make sure you give brilliant talks at national and international conferences. Make yourself visible, even as a postdoc. If opportunities arise, people need to know you exist; if you hide in the lab or your office, people may not think of you even if you are be the best person. I realise this is not specific to social insect research….

Your baby doesn’t look so well …or the effects of developmental stressors on larvae in a young termite colony

A blog post highlighting the article by T. Chouvenc, M. Basille and N.-Y. Su in Insectes Sociaux

By Thomas Chouvenc

One of the reasons for the success of social insects is that their nest provides a homeostatic fortress for the colony, protecting it from external environmental changes and external threat. This is particularly true in large, mature colonies of ants, termites and bees, where a large worker cohort can provide optimal care for the developing brood and the modification of the nest structure itself provides a safe “home”.

However, like any other organisms, social insects may still be susceptible to developmental stress. Embryos first develop in the womb (or egg), and after birth continue to develop until it reaches maturity (adulthood). During this development phase, an individual is subjected to environmental and epigenetic stressors throughout its growth phase. Fluctuating asymmetry has historically been used as an indirect measure of exposure to developmental stress, and the relationship is that, the more stressful the conditions are for a developing organism, the more it will display asymmetrical traits at the end its development.

In the Asian subterranean termite, Coptotermes gestroi, soldiers sampled from mature colonies display highly symmetrical traits, suggesting that conditions for a developing termite in a large and healthy colony are optimal, and very little stress is imposed on the developing brood (Chouvenc et al. 2014). This is because there is an army of workers taking care of them in the most dedicated nursing behavior. However, in newly started colonies, the king and queen are alone to take care of their initial brood, and for many months, all the young termites hatching and developing in this stressful environment are subjected to limited resources and less than optimal parental care. As a result, the first few termites produced in a new colony are highly deformed and display highly asymmetrical traits. However, as the colony grows and additional workers are produced, the brood receives additional care and the individuals produced are progressively looking more symmetrical. I sent a few termite samples from my incipient colonies to a colleague for identification, without telling him the origin of the samples. His response was: “Tom, your samples are all messed up! You didn’t do a good job conserving the samples.” The fact was I preserved them in the same way that I preserved my other samples but the source of the deformed samples was from a young colony.

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A: C. gestroi soldier from an incipient colony, B: Soldier from a mature colony.

In Chouvenc et al. 2017, we showed that the quality of termites produced in a colony improves over time and that, as the colony grows, termite eggs and larvae develop in better conditions, resulting in “better looking” termites. We were able to identify two independent origins of the stress imposed on very young termite colonies. First, the quality of brood care was found to be critical in producing highly symmetric individuals, and that the more workers present in a colony, the more symmetrical the newly produced termites looked. Second, in the first year of development, the termite colony produces “cheap” soldiers, as their development is accelerated.

These cheap soldiers are a way for the colony to quickly produce a few soldiers to defend the young colony and reach the optimal soldier ratio for the colony (Chouvenc et al. 2015). However, accelerated development imposes a heavy stress on developing soldiers, which display strong asymmetrical traits as a result. Later in the life of the colony, soldiers are then produced through a different developmental pathway, with additional time and resources invested in them, resulting in larger, better looking, and more functional soldiers.

Therefore, a newly established termite colony is extremely limited in its caring capacity, time and resources, and the initial investment in the first brood is very poor, resulting in termites exhibiting morphological evidence of their stress. When the colony grows, the care toward the brood improves and more time and resources are allocated to the new brood, providing stable developing conditions resulting in “good looking” termites.

One could say that the appearance of a termite may not say much about the quality of an individual, however these asymmetric individuals produced early in the life the colony have a short life span, confirming the cost of developmental stress on their individual physiology and metabolism. Workers and soldiers produced from the first initial egg batch laid by the queen usually die within the first year of the life of the colony (Chouvenc and Su 2014). In contrast, termites that developed in a mature colony in optimal conditions can live up to four years. Therefore, the initial parental and alloparental care toward the developing brood can directly be a measure of the initial investment in larvae, and the longevity and functionality of the resulting individual, a measure of the return on investment.

References

Chouvenc T and Su NY. 2014. Colony age-dependent pathway in caste development of Coptotermes formosanus Shiraki. Insectes Sociaux, 61: 171-182.

Chouvenc T, Basille M. Li H-F and Su N-Y. 2014. Developmental instability in incipient colonies of social insects. PloS one, 9: p.e113949.

Chouvenc T, Basille M and Su N-Y. 2015. The production of soldiers and the maintenance of caste proportions delay the growth of termite incipient colonies. Insectes Sociaux, 62: 23-29.

Chouvenc T, Basille M and Su N-Y. 2017. Role of accelerated developmental pathway and limited nurturing capacity on soldier developmental instability in subterranean termite incipient colonies. Insectes Sociaux. In press.