IS: Who are you and what do you do?

JF: I am Jennifer Fewell. I study the organization, evolution, and ecology of insect societies, primarily focusing on ants and honey bees.

IS: How did you end up researching social insects?

JF: I went into grad school to study the relationships between food and social organization (probably because I like to be social and to eat). My original goal was to study canids, but that became too logistically complicated. I had switched to birds as a focal taxon, but found that birds seem to be much smarter than I am. By my second year, I had switched advisors to the wonderful Mike Breed. One day he took me out to a local park that was covered in harvester ant nests (Pogonomyrmex occidentalis). We watched them for a while; then he gave me a paper by Bert Hoelldobler to read and told me to go home and think about them. The next day I had my dissertation project sketched out and I have never looked back. Social insects are so much more elegant and fascinating in their social organization than any other group.

IS: What is your favourite social insect and why?

JF: I can’t answer that. My favorites to watch have been ant queens and solitary bees. For pure attractiveness, I’d have to pick between a harvester ant, a leafcutter ant and a newly emerged honey bee. Honey bees are definitely the cutest, but harvester ants have a sleek but striated look to them that in my mind cannot be matched.

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

JF: My favorite experimental result was showing that normally solitary nest-founding ant queens show an emergent division of labor when forced to be solitary. We repeated and verified the finding in solitary bees. This first experiment tested a then new model of how social interactions affect individual phenotype in the context of division of labor and task organization. It set the stage for most of the work I’ve done since. The original study had fantastic results, but the idea was not well accepted at first. I argue that is okay, because it required a change in how we have to think about social phenotypes and selection. The doubt expressed by the scientific community at the time forced my lab to explore the paradigm in other species, and to test it more rigorously. So, it is a story of initial frustration in how science is discussed and received, but I think with a happy ending…although nothing in science does or should actually have an ending.

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

JF: I teach animal behaviour and sociobiology. One of the things I like about teaching the courses is that they force me to be less insect-centric in my thinking about social evolution, and to be more aware of the diversity of social forms out there. So, my teaching has helped to shape my research as much as my research has helped to shape my teaching.

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

JF: Ah no – I read a lot of science fiction for fun, and so don’t have a very worthy suggestion. I am currently also reading Jim Costa’s “The Other Insect Societies”, which I would recommend any social insect student owning – to remind us that ants, bees, wasps (and termites) do not represent the whole social insect world.

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

JF: The book that most influenced me as an undergrad was Wilson’s book, “Sociobiology: The New Synthesis”. I don’t want to say how far back that was, but I vividly remember reading the book in my advanced animal behaviour class, and I felt that I’d found a new world to explore and a new way to explore it. Wow.

I suppose that now the world has incorporated and moved forward from that text. For the incoming social insect student, Hoelldobler and Wilson’s “The Superorganism” is wonderful. Way back, Hoelldobler’s work set me down my research path, and this book may do the same for some other student.

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

JF: I ride horses.

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

JF: I fuss out and complain a lot to my poor husband. Then I stay up late and get things done.

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

 JF: As a biologist, I would have to say that depends entirely on the ecology of the island.

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

JF: Mike Breed, my grad advisor (as already mentioned) got me started on my research path, and has been a steadying and encouraging presence ever since. My current work traces directly back to the influence of Rob Page, with whom I worked on honey bee division of labor, and whose ideas still shape much of what I do. But my decision to make animal behavior a career started when I took a course in college with Bill Dilger, an ornithologist and ethologist. Bill was the consummate natural historian. We would go for walks in the woods, and Bill would point out songs and behaviors well beyond what I would see…and then explain what was going on around us. I began thinking of the animals around us as a city of arguing, cajoling and romancing individuals, all living interesting lives.

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

JF: Work at it, and learn to design experiments correctly – models and theory are important, but the experiment done well gives you an answer.

Highlighting the article written by T. Saga, M. Kanai, M. Shimada and Y. Okada in Insectes Sociaux

Written by Insectes Sociaux Editor in Chief, Michael Breed

In this issue of Insectes Sociaux Saga et al (2017) present a fascinating long-term study of nest usurpation and social parasitism in Vespula wasps. Reproduction based on usurpation is relatively rare in vespine wasps and outcomes are often only anecdotally reported. Vespula flaviceps and V. shidai can each have colonies with normal reproductive strategies, but some queens in each species usurp nests of either their own species (intraspecific usurpation) or the other species (interspecific usurpation).   Saga et al (2017) focus on interspecific usurpations. In an eight-year study they documented ten cases of interspecific usurpation. In nine of these the resulting colony had a V. shidai queen and in the remaining one the queen was V. flaviceps. The workers in these colonies were predominantly V. flaviceps, but the gynes and males produced were nearly all V. shidai. This suggests that V. shidai has a selective advantage in this relationship and raises the interesting question of whether facultative social parasitism can provide a route to the evolution of obligate parasites.

Facultative social parasitism differs from obligate relationships in that facultative usurpers exploit the nest as a resource but can also produce their own workers. In facultative parasitic wasps the usurped colony may ultimately contain a blend of host and parasite workers or may consist of only parasite workers. Obligately parasitic social wasps, on the other hand, must always exploit the workers of the host species, as they only produce sexuals, not their own workers.

Based on the observations that V. flaviceps nests usurped by V. shidai produced sexuals of V. shidai, these facultative social parasites present provocative questions in understanding animals’ reproductive choices. Among the social wasps, three types of social parasitism are known: intraspecific facultative nest usurpation, interspecific facultative usurpation, and obligate social parasitism (e.g. sulcopolistes species group of Polistes (Cervo 2006), Dolichovespula arctica (= adulterina)) but whether the former two are evolutionary stops on the road to obligate social parasitism are unknown.

Facultative social parasites seem to make a reproductive choice to usurp a nest, rather than establish one on their own. The choice of host species usually follows Emery’s rule- that a socially parasitic species exploits its taxonomic sister species. However, this is not always true, and relatively closely related species, with similar social behavior and communication, are pre-adapted to exploit each other by virtue of possessing the “keys to the kingdom”, a repeated theme in the discussion of the evolution of social parasitism (Breed 2016). Thus social parasites often belong to the same genus as their hosts.

But little is known about the genetics that underlies social parasitism in wasps, and possibly differing reproductive strategies reflect underlying genetic divergences within populations. Within-species sympatric divergence—Emery’s rule strictly applied- is very rare and seems an unlikely route to obligate parasitism. Facultative social parasitism can be an evolutionarily stable strategy, rather than a step towards obligate parasitism (Lowe 2002). However, in relationships such as the one described by Saga et al (2017) one species could gain the upper hand in competition among free-standing nests while the other could evolve superior parasitic strategies. In that case the outcome could be the evolution of obligate parasitism by the species that is the superior parasite but inferior independent competitor.

Vespula flaviceps and V. shidai are already distinct species. Saga et al (2017) fill out a more complete picture of the outcomes of facultative social parasitism among similar species; their work has high value in adding to our understanding of these intriguing relationships.

References

Breed M D (2016) Social parasitism: the keys to the kingdom. Insect. Soc. 63:3–4
DOI 10.1007/s00040-015-0458-7

Cervo R (2006) Polistes wasps and their social parasites: an overview. Ann. Zool. Fennici 43: 531–549

Lowe RM, Ward SA, Crozier RH (2002) The evolution of parasites from their hosts: intra- and interspecific parasitism and Emery’s rule. Proc R Soc B 269:1301–1305

Saga T, Kanai M, Shimada M, Okada Y (2017) Mutual intra- and interspecific social parasitism between parapatric sister species of Vespula wasps. Insect. Soc.
 DOI 10.1007/s00040-016-0519-6