In termites, the evolution of alate body size caught between two opposing selective forces

A blog post highlighting the article by T. Chouvenc in Insectes Sociaux

By Thomas Chouvenc

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Alates of Coptotermes gestroi emerging during a dispersal flight event, with soldiers guarding the exit holes.

Sexual selection and partner choice have been hot topics in behavioral ecology over the past few decades, as scientists have been investigating impressive cases of sexual dimorphism and extreme attributes both in vertebrates and arthropods. In some social Hymenoptera, the males are often reduced in size and function compared their female counterparts. The need for a massive accumulation of metabolic reserves in these males has decreased over evolutionary time as their role has been reduced to simple yet functional sperm missiles. In termites, such extreme reduction of the male size is not present (despite cases of significant sexual dimorphism): both the female and male are essential during colony foundation as they provide exclusive monogamous biparental care within the first few months of the life of the colony. The royal couple will then spend years, sometimes decades together, contributing solely to reproduction. One might argue that such lifestyle should promote the evolution of ‘picky’ mate selection.

However, during the dispersal flight and colony foundation of termites and many other eusocial insects, the potential for partner selection may be minimal due to the chaotic nature of mating swarms, when individuals only have a few minutes to find a partner and create an incipient colony or die. My anthropomorphic self likes to see it as an extreme form of speed dating. This mating behavior implies that being too choosy in mate preference would be counter-selected, especially when predation pressure is high. However, some lines of evidence suggest that ‘high quality’ primary reproductives could experience improved mating success, survival traits, fertility, and ultimately colony foundation success. Hence, despite an overall absence of mate selection, there could still be passive evolutionary selection for alate size or quality.

In termites, two main opposing selective forces may drive the evolution of the overall alate body size during colony foundation events.

The first selective force, as outlined by Nalepa (2011), is inherent to the biology of termites. Both the king and queen are monogamous partners, and each contributes to the biparental care of their first cohort of offspring. However, as the first functional workers emerge, the brood care duties irreversibly shift to the workers, resulting in constant alloparental care as the queen and king lose their ability to provide care for their brood (Chouvenc and Su 2017). Nalepa argued that in incipient termite colonies, the rapid switch from biparental care of the first brood to alloparental care of subsequent brood has resulted in reduced selection for the accumulation of large metabolic reserves in imagoes. As evidence for this, queen and king fecundity is maintained despite a relatively small body size (when compared to their ancestral wood roaches). The directional reduction of body size in termite imagoes may, therefore, have allowed mature termite colonies to increasingly invest into the number of alates to optimize their dispersal success rate.

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Young Coptotermes formosanus colony, where the workers have already taken over parental care duties.

The second selective force is opposite to the first one, as the limited metabolic reserves of relatively small termite alates during colony foundation leaves little room for inefficiency. The quality of the first brood is important for colony foundation success and the initial input from the queen and king are critical to jump-start the colony and improve its long term success within a highly competitive environment. Such pressure might incentivize mature colonies to invest in high-quality alates with enough internal metabolic resources to successfully produce their first cohort of functional workers during the incipient colony phase.

In dispersal fight events, Coptotermes gestroi alates may rapidly be killed by a wide range of predators. In this video, Pheidole megacephala was able to capture most alates that landed on trees or on the ground, which show how luck can be an essential factor on alate survival, independently of the quality of individuals.

In my 2019 study, I was able to take advantage of large dispersal flight events of Coptotermes gestroi (Rhinotermitidae) with high intracolonial and intercolonial variability in size to test the actual role of alate body size in colony foundation success and growth within the first nine months after foundation. I was able to measure 79% colony foundation success (n = 175), and most colonies that failed to establish had relatively small males and females, suggesting that mated pairs with relatively large individuals had a higher chance of surviving the first few months. This data suggests that, although the rapid transition to alloparental care in incipient colonies might reduce the need for accumulation of substantial reserves in alates, the mated pair still requires a bare minimum of initial metabolic resources to initiate efficient colony foundation and provide biparental care. Also, a positive correlation between the initial king and queen weights and colony growth was found despite high colony growth variability. Both the king and the queen initial weights were relevant for colony growth when considered separately, confirming the importance of biparental care, but when combined, only explained 27% of the observed variability despite highly standardized rearing conditions.

This study confirmed that during colony foundation in laboratory conditions, the initial weight of C. gestroi females and males plays a role in colony foundation establishment and initial colony growth rates. However, such laboratory results need to be placed in the perspective of the harsh conditions of field dispersal flights, where the vast majority of alates die rapidly and founding conditions are highly heterogeneous and hazardous. Therefore, the importance of alate weight may be secondary to many other environmental factors and luck. As previously suggested (Hartke and Bear 2011), sexual selection for large alate body size in termites during and after dispersal flights may be extremely weak and secondary to a wide variety of other selective pressures.

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Alates of Coptotermes gestroi emerging from a tree trunk by the thousands and ready to fly out.

Mating flights in C. gestroi termites can comprise hundreds of thousands of alates, and the large number of alates produced may be more relevant to the final number of established incipient colonies than the marginal advantage that relatively large alates may have during colony foundation. Such a reproductive strategy primarily relies on “inundative” dispersal flights, which may also have reduced the importance of alate weights during colony foundation. The trajectory of the reproductive strategy of a given termite species may partially be reflected in the size of their imagoes, an investment into reproduction which reflects the life history of the species. Over evolutionary time, termite colonies have optimized this quality/quantity trade-off in alate production, which varies among species.

In the light of its remarkable invasive abilities and its high colony establishment rate in the laboratory, C. gestroi may be a termite species that is able to efficiently optimize such balanced investment and adapt to various environmental pressures during dispersal flights and colony foundation.

References

Chouvenc, T., & SU, N. Y. (2017). Irreversible transfer of brood care duties and insights into the burden of caregiving in incipient subterranean termite colonies. Ecological entomology, 42(6), 777-784.

Chouvenc, T. (2019). The relative importance of queen and king initial weights in termite colony foundation success. Insectes Sociaux, 1-8.

Hartke, T. R., & Baer, B. (2011). The mating biology of termites: a comparative review. Animal Behaviour, 82(5), 927-936.

Nalepa, C. A. (2011). Body size and termite evolution. Evolutionary Biology, 38(3), 243-257.

Behind-the-scenes of the Insectes Sociaux best paper 2018

A blog post highlighting the article that received the prize for the best paper published in Insectes Sociaux in 2018 by Paul J. Davison and Jeremy Field.

By Paul Davison and Jeremy Field

 

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Jeremy at a Lasioglossum malachurum nest site in Spain

Paul’s Ph.D. focussed on the unusually varied social biology of sweat bees, which include eusocial species, solitary species and also socially polymorphic species. In socially polymorphic sweat bees, some populations have eusocial nests with a queen and workers, while in other populations of the same species all nests are solitary. Solitary populations are always found at cooler latitudes and/or higher altitudes than eusocial populations. Likewise, obligate eusocial species, in which nests always have queens and workers, never occur at the coolest latitudes or higher altitudes alongside solitary species or populations. The main element of the Ph.D. involved performing a field transplant to explore how the environment influences behaviour in a socially polymorphic sweat bee (for the results, see Davison & Field (2018) Behavioral Ecology & Sociobiology 72:56).

 

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A Lasioglossum malachurum foundress resting by the entrance to her new nest in spring

 

We thus became interested in what limits the geographic distribution of eusociality in sweat bees. It has long been thought that once the growing season becomes too short, it is no longer possible to sequentially produce the successive worker and reproductive broods necessary for eusociality and the only option is solitary nesting. Noticing that this had not been tested experimentally, we thought it would be interesting to do just that. The best way would be to conduct another transplant, only this time of an obligate eusocial sweat bee far to the north of its natural range.

 

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Freshly removed buckets containing newly dug nests ready to be packed for transplant

 

We chose to transplant Lasioglossum malachurum, a well-studied obligate eusocial sweat bee that is restricted to the south and east of Britain. We wanted to investigate the reasons for this, and in particular whether it is related to the length of the season. Because of other fieldwork commitments, this project would have to be ‘smash and grab’, or ‘smash and transplant’. Jeremy had the ingenious idea of getting spring foundresses to nest inside plastic buckets and then transplanting them and their nests wholesale. To do this, we spent winter digging trenches adjacent to where the bees nested in southern England, filling buckets with the excavated soil then putting them back into the trench and filling in the gaps. In essence, digging holes and filling them in again! By transplanting buckets after nests had been initiated in spring but crucially before foundresses began provisioning, we could test how being in a northern environment with a shorter season would impact the eusocial lifecycle.

 

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Embedding buckets in the garden of the University of Aberdeen’s Lighthouse Field Station at Cromarty (Photo: Paul Davison)

 

We were generously allowed to embed our transplanted buckets in the garden of the University of Aberdeen’s Lighthouse Field Station at Cromarty in northern Scotland. Cromarty is much further north than where L. malachurum occurs naturally and is a place most people have only heard of thanks to the BBC Radio 4 shipping forecast. Nestled between the 1840s lighthouse and stunning Cromarty Firth, the bees would certainly have a good view if nothing else. Equally generously, since it involves hours of scraping away at a block of soil on a table and is incredibly messy, Paul was able to excavate the buckets in rooms owned by the Cromarty Arts Trust. We transplanted control buckets to the University of Sussex campus, well within the bee’s natural range. All that remained was to see whether driving the length of Great Britain with buckets of nesting sweat bees would pay off.

 

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Digging a hole adjacent to the Lasioglossum malachurum nest aggregation in southern England for embedding buckets (Photo: Paul Davison)

 

The results were unequivocal. When we excavated the nests eight weeks after transplanting them, first brood offspring at Sussex were all nearing the completion of development, whereas in Scotland most offspring were still tiny larvae that had not long hatched. We estimated that this represented a lag of approximately seven weeks behind Sussex and that, had they been left to complete development, the first brood in Scotland would not have emerged as adults until August! This would leave no time for workers to provision a reproductive brood successfully. We found that the time lag corresponded to differences in temperature, which is well known to influence the timing of bee activity and seems to have caused foundresses in Scotland to begin provisioning much later in the spring. Importantly, this reflects environmental constraints on provisioning behaviour rather than the strategic shift between social and solitary nesting seen in some socially polymorphic sweat bees (Field et al. (2010) Current Biology 20:2028-31).

 

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A Lasioglossum malachurum nest entrance with a red marked female sitting just inside the entrance

 

All in all, some intriguing results. Jeremy is planning to take this initial work further with more replicates and a detailed study of what exactly causes the time lag.

Red wood ants stalked by a Trojan horse

Highlighting upcoming research from Thomas Parmentier entitled ‘Host following of an ant associate during nest relocation’, to be published shortly in Insectes Sociaux

Even more fascinating than ants, is the extremely diverse group of arthropods that live strictly in their nests. Gradually, we learn that these creatures, commonly  referred to as myrmecophiles or ‘ant loving’, possess an array of chemical, morphological and behavioural adaptations to by-pass ant aggression and to make a living in the hostile nest environment (Kronauer and Pierce 2011). Many myrmecophiles are parasites that feast on a lavish banquet of brood and other resources found in the nest (Parmentier et al. 2016a).

What is rather unknown so far, is how myrmecophiles move in the landscape and target new nests. It can be expected that myrmecophiles are prompted to colonize new nests, when nest conditions start to deteriorate or when competition with other myrmecophiles becomes too strong. During my current postdoc project, I study the spatial dynamics of myrmecophiles associated with European red wood ants. These ants are famous for their large mound nests and aggression, yet their nests harbour a rich community of myrmecophiles (Parmentier et al. 2014).

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Last spring, I visited a study site in the north of Belgium and to find out whether the wood ant colonies (Formica polyctena) made it through the winter and whether new nests were founded. Then, I observed that one colony was moving to a new nest site a couple of metres away. As I have been curious for a long time how myrmecophiles would respond to the desertion of their home, I carefully inspected the horde of moving workers. To my surprise, I saw that a group of larvae of the beetle Clytra quadripunctata (Chrysomelidae) were crawling among the moving colony towards the new nest site. A bit later, some larvae were also dragged by the workers to the new nest. Luckily, these days, smartphones are equipped with rather decent cameras, so I was able to record this rare event. There are some old and anecdotal notes which suggest that some myrmecophiles are also able to track their host during relocations to a new permanent nest site, but this has not been recorded so far.

The biology of Clytra quadripunctata is rather peculiar. The adults are adorable beetles that feed on plants near the nest. After mating, the female drops her eggs. The larvae enter the nest and remain there probably for 2 years (Donisthorpe 1902). Lab tests demonstrated that the larvae are brood predators and scavengers. They preferentially reside in the heated brood chambers in the centre of the nest (Parmentier et al. 2016b). The larvae of this beetle are protected by a pear-shaped case in which they can retract. After pupation, the adults sneak out of the ant nest.

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My observations suggest that the beetle larvae adaptively respond to rare nest-moving events. Interestingly, they can find the new nest site on their own or be carried by workers unaware of the danger that is hiding in the case. Nonetheless, a significant fraction of the larvae did not find the new nest and remained in the abandoned nest. Wood ants are thought to move occasionally when microclimatic conditions become suboptimal. However, they may also be triggered to relocate to a new nest site in order to reduce parasite load. This could end up in an evolutionary arms race where the host will move more frequently and more distantly, whereas the parasite will develop more advanced strategies to follow or locate its host. This is a tempting hypothesis that deserves further research.

This observation has galvanized me to unravel some more secrets of myrmecophile dispersal the coming years. More information on the progress of my research on myrmecophiles can be found at:

https://www.researchgate.net/profile/Thomas_Parmentier

 

Donisthorpe HSJK (1902) II. The Life History of Clythra quadripunctata, L. Trans R Entomol Soc London 50:11–24.

Kronauer DJC, Pierce NE (2011) Myrmecophiles. Curr Biol 21:208–209.

Parmentier T, Dekoninck W, Wenseleers T (2014) A highly diverse microcosm in a hostile world: a review on the associates of red wood ants (Formica rufa group). Insectes Soc 61:229–237.

Parmentier T, Bouillon S, Dekoninck W, Wenseleers T (2016a) Trophic interactions in an ant nest microcosm: a combined experimental and stable isotope (δ13C/δ15N) approach. Oikos 125:1182–1192

Parmentier T, Dekoninck W, Wenseleers T (2016b) Do well-integrated species of an inquiline community have a lower brood predation tendency? A test using red wood ant myrmecophiles. BMC Evol Biol 16:12.

 

2018 Highlights from Our Community

Hello, social insect community!

2018 was productive for the social insect community, especially for Insectes Sociaux. As the new Social Media Editors, we have been enjoying collaborating with many social insect scientists on blog posts. Thank you for your contributions not only to making our journal great but also our blog, whether that’s through reading or writing! As 2018 came to an end and we were reflecting on the year, we reached out to past blog contributors to see what they’ve been up to. Here are some 2018 highlights from social insect scientists:

Kaitlin BaudierPostdoctoral Research Associate, School of Life Sciences, Arizona State University

You can find Dr. Baudier at kmbaudier.weebly.com and @AntGirl_KB. She also has a YouTube channel.

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IS: What is the most exciting thing you’ve learned about your study species in 2018?

KB: On the army ant front (pun intended) I learned a lot about bivouacs in 2018. It turns out that bivouacs of the most well-studied army ant (Eciton burchellii) do not strictly thermoregulate as was previously thought. At high elevations, we found that bivouacs selected different thermoregulatory strategies dependent on brood developmental stage. When ambient temperatures were low and bivouacs were filled with predominantly larvae, bivouacs would allow energy-conserving cooling. However, bivouacs rich in pupae were always kept warm regardless of ambient temperature. We report on this energy-saving strategy for coping with high elevation cold temperatures in our recent paper in Ecography. This was an interesting turn in our bivouac elevation project which we first published in Insectes Sociaux back in 2016.

2018 also marked my first work on the topic of nest defense in the stingless bee Tetragonisca angustula. This species is famous for having two types of nest entrance guards: hovering and standing guards. In our paper currently in revision at Behavioral Ecology, we report that task allocation between these two guarding jobs is age-dependent, with younger bees hovering guarding and older bees standing guarding. This was an unexpected and exciting finding in our study which had initially set out to collect task allocation data for a bio-inspired design project aimed at improving defensive swarm algorithms in unmanned aerial vehicles (Strickland et al. In Press). We also found that roaming Ectatomma tuberculatum ants use sit-and-wait predation to make a meal of these guard bees. Life for a guard bee can be rough.

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IS: What was your favorite conference and/or fieldwork experience?

KT: IUSSI 2018 in Brazil really blew the top off of my idea of what a great conference could be. Not only did I get a chance to speak with a multitude of established social insect biologists from around the world, but it was an excellent opportunity for me to meet a lot of amazingly dedicated students and to learn about their respective projects. I walked away from Brazil 2018 with more than a few new collaborators. As for fieldwork, I have been having an extremely positive experience working with the Smithsonian Tropical Research Institute in Panama this past year. From my fieldwork in and around BCI and Gamboa to my returning to co-instruct the ASU Tropical Biology course at STRI in the summer, I have enjoyed getting to know the insects, the people, and the environment in Panama. As 2019 begins, I am already packing my field equipment for another trip back. Some days I can’t help but think that it doesn’t get any better than this.

 

Rachael BonoanPost-Doctoral Researcher, Tufts University and Washington State University

You can find Dr. Bonoan at www.rachaelebonoan.com and @RachaelEBee.

IS: What is the most exciting thing you’ve learned about your study species this year?

RB: This year, I started a post-doc studying the natural history of an ant-caterpillar relationship in a Pacific Northwest prairie. When it’s a caterpillar, the Puget blue butterfly, is protected by ants. In return for protection, the caterpillar secretes a sugary snack for the ants. As mentioned in my Interview with a social insect scientist, part of my job is to figure out which ants live on the prairie with my Puget blue caterpillars.

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With the help of two Tufts University undergraduates, Hanna Brush and Max McCarthy, we have identified ten species of ants on our field site! (Many thanks also go out to Stefan Cover at the Harvard Museum of Comparative Zoology and Chad Tillberg at Linfield College for help identifying and pinning specimens.)

So far, there are two dominant ant species on our prairie: Formica obscuripes (the Western thatch ant) and Tapinoma sessile (the odorous house ant). We have seen both tending Puget blue caterpillars, this bodes well for the baby butterflies!

The most exciting species we identified, however, is Ployergus mexicanus, also known as the raider ant or the pirate ant. The raider ant has sickle-shaped mandibles (mouthparts) specialized for kidnapping young from other ant colonies. The ultimate moocher, this ant species cannot feed itself or take care of its own young.

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After mating, a female raider ant infiltrates the colony of another ant species, typically a Formica species. The female raider ant subdues Formica workers with a specialized pheromone and promptly overtakes their queen. With the Formica queen out of the way, the raider ant queen is ready to begin her reign—she lays eggs that the Formica workers raise. With the help of their sickle-shaped mandibles, raider ant workers spend their days raiding other Formica colonies and kidnapping their young. This ensures that there will always be enough Formica workers to raise more raider ant workers.

IS: What was your favorite conference and/or fieldwork experience?

RB: This year, I attended two great conferences: Entomology in Vancouver, B.C. and Social Insects in the North East Regions (SINNERS) in Philadelphia, PA. While I enjoyed both conferences, SINNERS was held at the coolest conference venue: the Natural Academy of Sciences of Drexel University (a museum!). During the meeting, the museum had a fantastic exhibit: Xtreme Bugs! This exhibit celebrated “extreme insects” with giant, animatronic models of the amazing beats. My favorites were, of course, the leafcutter ants and the honey bee!

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Excellent venue aside, SINNERS is one of my favorite conferences. This relatively small conference (~50 speakers this year) gives you the opportunity to get to know social insect scientists! Since it’s a regional conference, SINNERS also a great meeting to find nearby social insect friends and collaborators. I met James Waters at SINNERS 2015, and we have continued to stay in touch! James and his students have visited my honey bees at Tufts (they even lent us a wireless temperature sensor for my research), and I have given a couple guest lectures in James’s classes at Providence College!

 

Tomer CzaczkesACElab Group Leader, University of Regensburg

You can find Dr. Czaczkes at animal-economics.com and @tomerczaczkes.

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IS: What is the most exciting thing you’ve learned about your study species this year?

TC: We started trying to train Drosophila to associate odours with food qualities. Man, those things are thick as glue! It gave me a real appreciation for our study species, Lasius niger – we found that these ants can learn an odour / food quality association reliably after just one exposure. I admit that perhaps the flies could learn that quickly if one used precisely the right method. Perhaps. So maybe rather than being thick, they are fiddly and delicate. Really makes me appreciate how robust and easy to work with our ants are.

 

The Insectes Sociaux editors have also been curious about our social media followers. To learn more about the kinds of scientists in our Twitter community, we recently put out a series of polls. Overall, we’ve learned that most of our followers study behavior and bees, and wish they had more time for fieldwork. Here are the results!

 

“We know all social insects are great, but what is your favorite?”

41% Bees

40% Ants

12% Wasps

7% Termites

 

“What do you predominantly study?”

51% Behavior

18% Ecology

6% Morphology

25% Combination of all of the above

 

“What component of your work do you wish you had more time for?”

49% Fieldwork

35% Publishing/writing

8% Teaching

8% Outreach / science communication

 

What have you been up to recently with your science? Do you have a comment or suggestion for our blog, social media presence, or journal? We would love to hear from you! Follow us and send us a message through Facebook, Instagram, or Twitter.

Happy new year! We hope you have fulfilling scientific endeavors in 2019.

Madison Sankovitz & Bernie WittwerSocial Media Editors, Insectes Sociaux

 

A high-speed camera reveals a new behavior of honey bees

A blog post highlighting the article by S. Łopuch & A. Tofilski in Insectes Sociaux

By Sylwia Łopuch and Adam Tofilski

 

The behavior of honey bees (Apis mellifera) still contains a plethora of mysteries. After many decades of research, bee communication is still not entirely understood. Efficient communication is particularly important for social insects such as honey bees because a single colony consists of tens of thousands of bees that need to cooperate to survive.

A high-speed camera may be beneficial to the study of social insect communication because it can record thousands of frames per second. As a result, high-speed video recording lets us see details that are undetectable to a human eye.

Observations of a few colonies of honey bees with the use of a high-speed camera revealed that the bees moved their wings in temporal and behavioral patterns within the nest. We housed colonies in observation hives (which consisted of two frames with bees placed behind glass walls) and recorded the bees’ behavior. The wings remained motionless most of the time. However, occasionally bees with folded wings performed a few wing beats. Interestingly, this behavior was observed not only in workers but also in queens and drones. The wing movements were detected most often during the swarming season (the reproduction period for honey bees). The queens performed this wing behavior only at that time. Similarly, drones vibrated their wings only during preparation for mating flights and when they were evicted from the nest by workers. The wing movements were observed most often in workers, which moved them both during the swarming season and outside of it (video). Workers moved their wings when they were in contact with a queen or another worker, including workers returning to the nest with food (pollen or nectar) and those guarding the nest entrance.

Our observation that the honey bees moved their wings when they were in contact with other bees led us to assume that the function of the wing movements is related to communication. We also recorded wing movements of dancing bees. Workers perform the waggle dance when they find an attractive source of food. After they return to the nest after foraging, they dance to transfer information to other nestmates about the location of the food source. It is possible that frequency of wing beats (the number of wing beats per second) and duration of episodes of wing beating transfer some information because these metrics significantly differed in queens, drones, and workers. The characteristics of the wing movements also depended on temporal context, differing in the swarming and non-swarming seasons. Therefore, wing movements may support communication based on vibrations in the darkness of nests where visual cues are ineffective.

In conclusion, high-speed video recording allows us to observe unknown behaviors of honey bees like wing movements and help us better understand their meaning.

Interview with a social insect scientist: Jan Šobotník

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IS: Who are you and what do you do?

JS: My name is Jan Šobotník, and I am an Associate Professor at the Faculty of Forestry and Wood Sciences, Czech University of Life Sciences in Prague (Czech Republic). I am the head of the Termite Research Team (see https://termiti.fld.czu.cz/en/or https://www.facebook.com/TermiteResearchTeam/), a group of researchers and students working on the ecology of termites at the global scale.

IS: How did you develop an interest in your research?

JS: I began my research by studying the physiology and chemical ecology of termites, and gradually shifted into field research. I am always amazed by the incredible intricacy of tropical ecosystems and the role of termites as key players in these ecosystems.

IS: What is your favorite social insect and why?

JS: I am truly fascinated by the contrast between the vulnerability of termites and their dominance in tropical ecosystems – at our plot in Cameroon, there are about 5,000 termites per square meter! They function as ecosystem engineers, moving tons of material per hectare and year and fundamentally influencing not only terrestrial biomes but, through the release of greenhouse gases, the temperature at the global scale. However, when their environment becomes less controlled, they quickly become prey or die in a Petri dish within tens of minutes!

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

JS: I really enjoyed the work we did on Neocapritermes taracua. It is a common soil-feeding termite in French Guiana, and we described incredibly complex defensive mechanisms in workers. At the beginning of this work we didn’t know much about them, but we knew that we were dealing with a fascinating system. We have continued working with N. taracua in order to reveal as much as we can about their colonies.

IS: Do you teach or do outreach/science communication? How do you incorporate your research into these areas?

JS: I participate in all these activities to a variable extent during the year, and, among others, I helped to create a documentary movie, “The World According to Termites”, which has been successful at documentary movie festivals such as Life Science Film Festival 2017 (major award) and Wildlife Vaasa Festival (winner of the science category).

IS: What do you think are some of the important current questions in social insect research and what’s essential for future research?

JS: I think it is important to understand the evolution of eusociality. This research has been furthered by the rapid development of new sequencing tools, allowing us to study proximate developmental mechanisms and also infer new phylogenies of unprecedented resolution. Another important research question concerns the ecological performance of particular species: What makes some species more ecologically successful and others? These questions are fundamental and will help us understand which species are the most endangered by ongoing global changes!

Concerning future research, it is critical to reduce the negative impact of the human population on natural resources. Social insect habitats are being decimated by anthropogenic effects, which means that future scientists will not be able to study social insects in the same ways we do today.

IS: What research questions generate the biggest debate in social insect research at the moment?

JS: There is a little doubt that the modern sequencing approaches are changing science more than any other methods implemented in the past. So, in my opinion, the hot topic (beyond just social insect science) is how to deal with large datasets produced by new sequencing platforms.

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

JS: I recently finished reading Sapiens: A Brief History of Humankind by Yuval Noah Harari. I think it provides an excellent survey of anthropogenic impact on the Earth. It is a distressing read, but I highly recommend it for people who are able to change their lifestyle.

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

JS: I like photography, especially insect macro photography, although I do not have much time to play with insects outside of field work. Additionally, I recently moved to a house in a village close to Prague, so I am trying to create an enjoyable garden for my family and me along with a small biodiversity hotspot with plants blossoming throughout the year, a water source, dead wood, open soil, etc.

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

JS: I try to stay on top of things, not take the challenges too seriously, and not consider myself too important. Also, of course, I take comfort in my family, kids, and friends.

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

JS: Professors from my studies and colleagues from universities and research centres have had the most considerable influence. Surely my ex-supervisor, late Prof. Pavel Štys, to name at least one.

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

JS: Never give up! It might be hard, but if you work hard, read a lot, and follow your dream, you will be successful!

Interview with social insect scientists: Kaleigh Fisher and Mari​ West

Kaleigh and Mari are authors of the recently published review article, ‘Are societies resilient? Challenges faced by social insects in a changing world’.

 

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Kaleigh Fisher doing fieldwork in Chiapas, Mexico

 

 

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Mari West

 

IS: Who are you and what do you do?

KF: I am a graduate student in the Woodard lab at the University of California, Riverside. I am using methods from insect behaviour, evolution, and sensory ecology to understand how taste operates in bumble bees.

MW: I am a 3rd-year graduate student in the Purcell Lab in the Entomology Department at the University of California, Riverside. I study non-reproductive division of labor in ants, with the goal of understanding how continuous size variation and differences in chemical cues among workers affect how tasks are partitioned in social insect colonies.

 

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Kaleigh Fisher doing fieldwork in Chiapas, Mexico

 

IS: How did you develop an interest in your research?

KF: I was interested in agroecology and started working in a lab that studies insects in shade coffee farms in Mexico. I became interested in the ants and the stingless bees in this system. The research was super exciting; it was my first introduction to social insects, and I have been working with them ever since.

MW: I first became interested in social insects as an undergraduate at Cornell University, where I worked in Dr. Linda Rayor’s lab, studying behavioral dynamics between reproductive females in social spider colonies. These spiders are usually very tolerant of each other but can become quite aggressive (to the point of being cannibalistic) when vying for reproductive opportunity. Later, while working with an invasive ant species that is highly polygyne and super-colonial, I realized that there was a vast spectrum of cooperative behaviors within social groups. Since this realization, I have been interested in how social insects can coordinate these collective behaviors without any central control.

IS: What is your favorite social insect and why?

KF: My favorite social insects are the stingless bees. They are so interesting both biologically (eusocial, ~500 species) and culturally (long history of stingless beekeeping in Mexico). I worked with them briefly before starting to work with bumblebees and hope to have the opportunity to work with them in the future.

MW: Why do I have to have a favorite? They’re all awesome in their own ways.

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

KF: I think the best moment in my research so far happened a few weeks into my first field season on a shade coffee farm in Mexico for my master’s research. I stopped and thought, “wow this is awesome, I can’t believe this is my job!” It’s easy to get overwhelmed by all of the components involved with being in academia; I think it’s important to remind myself from time to time how exciting it is to ask a question about why or how insects are doing something, especially in the field, and then figure out a way to answer it. I realized how awesome that is in this moment. 

MW: Before I started my graduate work, I volunteered for a research project with the US Fish and Wildlife Service’s Crazy Ant Strike Team, whose goal is to eradicate the invasive yellow crazy ant from a Pacific island. The island serves as important nesting habitat for ground-nesting seabirds, which the ants significantly disrupt. My crew’s goal was to test a few different control/eradication strategies so that the next team could implement the most effective one. The project has been very successful, leading to almost complete eradication of the ants and a significant recovery in seabird reproduction on this island! It feels incredible to have been involved in a conservation project that has made a positive and lasting impact!

IS: Do you teach or do outreach/science communication? How do you incorporate your research into these areas?

KF: Yes, to both; I enjoy teaching (I have only had the opportunity to be a teaching assistant so far) and doing outreach. Depending on what I am teaching, I try to use relevant examples from social insects, especially bumblebees. I also really enjoy outreach. Depending on the group, I will introduce my specific research and why I do it or discuss the importance of pollinators and insects in general.

MW: Both as an undergraduate and graduate student researcher, I have been lucky to be part of entomology departments with strong focuses on outreach and I have been involved in many large-scale insect fairs throughout my academic career. Additionally, I have made it into many K-12 classrooms through these programs. I always try to incorporate my research into outreach events by introducing the basics of the colonial lifestyle and cooperative behavior of social insects. For more advanced audiences, I will also explain my experimental designs and findings.

IS: What do you think are some of the important current questions in social insect research and what’s essential for future research?

KF: A question that I am interested in is how environmental context shapes social behaviour. A lot of super informative research about insect sociality has come out of laboratory studies. I think building on those findings to capture how variable they are across different populations and species is essential.

MW: If you read our paper, Fisher & West et al. 2018, then you already know. 🙂

IS: What research questions generate the biggest debate in social insect research at the moment?

MW: My general feeling is that a lot of debate surrounds honeybees – whether or not they are good/necessary for ecosystem functioning and whether their long history of being farmed makes them a useful model system for studying social insects.

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

KF: The last book I read was the Ministry of Utmost Happiness by Arundhati Roy. It is fiction, but it has powerful social and political commentaries about current events in India and globally. I enjoyed it, so I would recommend it to those who enjoy novels with strong social commentaries.

MW: The Jungle, by Upton Sinclair. It’s certainly not very upbeat, but I do think it is relevant to some social and economic issues that our world faces today.  It was a thought-provoking read.

 

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Kaleigh Fisher and family in Chiapas, Mexico

 

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

KF: Outside of science, I like to spend time with my family (hiking, gardening, cooking together).

MW: Hiking and baking. I like exploring the outdoors, mainly to observe wild animals in their natural environment, and working with my hands to make something tasty to share with others.

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

KF: Whenever I feel overwhelmed, I try to step away from everything for a moment, even if that means just going for a walk, so that I can get a better perspective on everything.

MW: I usually remind myself how lucky I am that my job brings me outdoors on a regular basis and keeps me intellectually engaged. I try to give myself some time to relax outside, to reflect and refresh my outlook on life.

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

KF: I would bring my partner because he is an expert field biologist and awesome human, and a notebook and a pen (to help organize my thoughts/ideas).

MW: Having previously lived on an uninhabited island to which I was able to bring pretty much everything I ever wanted, this is a tough question to answer. However, if I had to choose, I would bring a snorkel for exploring the coral reefs (and maybe making fishing a little easier), some sunblock, and someone with whom to share the experience. In my experience, you don’t need much more.

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

KF: I think my master’s thesis advisors have had the most significant influence on my scientific career. They have inspired me to be inherently curious about insects while simultaneously instilling in me the importance of doing science consciously and with a moral compass.

MW: Without Dr. Linda Rayor’s influence, I probably wouldn’t be studying social insects today. She was an incredible mentor, and her enthusiasm for and ability to communicate about her science caught my attention immediately. In addition to getting me interested in social insect behavior, she has inspired me to share my science with others around me.

 

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A bumblebee foraging experiment conducted by Kaleigh Fisher

 

 

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Ant abdomen painted by Mari West during a mark-recapture experiment

 

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

KF: Give yourself time to explore what kind of research you are passionate about. Being excited about the questions you are asking and the research you are doing is what it is all about.

MW: I would encourage them to spend some time working on different projects so that they can identify the questions that they are most excited about and learn about what kinds of experimental design work well for those questions. I would also encourage them to spend many hours watching their study organisms, for fun and inspiration.

Interview with a social insect scientist: Thiago Silva

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IS: Who are you and what do you do?

TS: My name is Thiago Silva, and I am a researcher at the Universidade Federal do Paraná, Brazil. During my Msc. I studied the diversity of two genera of myrmicine ants (Acanthognathus and Strumigenys) in the Brazilian Atlantic Forest. My Ph.D. thesis stretched a bit to the morphological side, and I explored some aspects of the anatomy of several species of Strumigenys using web-based tools to annotate classes in online anatomic ontologies.

IS: How did you develop an interest in your research?

TS: As an undergraduate student, I became obsessed with insects, mostly wasps and grasshoppers. At the time, my supervisor (who is an ornithologist) was studying the edaphic fauna of one of the few national parks we have at the southern region of the Atlantic Forest. Knowing of my interest in insects, he invited me to study the ant fauna he collected at the site. With some reluctance (I really loved wasps) I accepted the challenge. When I laid eyes on my first mounted ant under the stereoscope, it was love at first sight.

IS: What is your favorite social insect and why?

TS: I love minute and shy social insects like Strumigenys inusitata. It is a bizarre-looking ant with a flattened head and a distinct hump over its mandibles (see image below). We do not know what the function of this structure is, but since most species belonging to this genus are slow-paced hunters living at the leaf-litter, we guess it might be related to a prey attraction strategy.

 

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Scanning electron microscopy of the head of Strumigenys inusitata. Left is anterior. Note the distinct hump at the anterior margin of the head.

 

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

TS: I do not remember any specific great discoveries during my research. I think that seemingly-small everyday discoveries, such as learning a little bit about the morphology of a cool group, are the most memorable moments to me.

IS: Do you teach or do outreach/science communication? How do you incorporate your research into these areas?

TS: I often talk about science and biology to undergraduate and graduate colleagues, whether in more casual settings at the university or during courses. I always try to highlight the importance of morphology to other disciplines in biology and how the study of phenotypes provides all sort of hints that enables us to understand a lot about biological systems.

Recently, I started talking more about representation of knowledge and the importance of clear communication in science. It is a somewhat new topic for me, so I am gradually incorporating these ideas in my talks.

IS: What do you think are some of the important current questions in social insect research and what’s essential for future research?

TS: Since social insects are extremely complex, I think there are numerous important questions that have to be (and are being) addressed. I believe that the most essential one is how sociality came to be in different groups of insects. Although its partial understanding does not impede the exploration of other important aspects related to sociality, I think the complete understanding of the origin of sociality is a primary topic of research for social insect scientists worldwide.

IS: What research questions generate the biggest debate in social insect research at the moment?

TS: Terminology always strikes me as the hot topic in my field of research and I think I always focus on it when reading about social insects.

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

TS: The last non-fiction book I read was Bruno Latour’s We Have Never Been Modern. It is a fascinating book and I recommend it, especially in the current social and political global context. The book deals with the modern duality of culture and nature and how this polarity affects decision-making at different levels within modern society.

The last fiction books I read were Haruki Murakami’s Kafka on the Shore and the graphic novel Black Dog: The Dreams of Paul Nash by Dave McKean. I would recommend any of the Murakami’s books, but Kafka is a favorite of mine since the characters depart from the typical constructs the author used in his previous works. Also, I love Murakami’s magical realism and references to popular culture. Black Dog is a must-read for those who want to take a glimpse at the nightmarish effects of war and understand how the first world war affected (and still affects) people at local and global scales. The mixed painting styles used by McKean and how their interplay with the narrative makes the reading extremely joyous.

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

TS: I spend most of my time outside of academic grounds reading or writing. I also like to get on the road and travel to other places. Sometimes one’s own mind is the best hobby one can have.

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

TS: I write my concerns away. I discovered that it is a useful sort of therapy for me. It organizes my thoughts, clearing the path that leads to the most unstressful resolution of a problem.

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

TS: Paper, pencil and the opportunity to leave the island! As Donne said, ‘every man is a piece of the continent’. Although I am very fond of reclusion from time to time, it is nice to be with kin.

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

TS: My parents and brother. My mother is a former researcher in obstetrics and always studied postpartum wellness and scientific methodology. My brother is an archaeologist/anthropologist and has always been concerned with the relation of public patrimony (especially archaeological sites) and traditional communities. My father is not a researcher, but always shared with me the delights of investigation and discovery. I think that a person’s major influences are those that are closest to them, providing support and teachings wherever they go.

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

TS: Love what you do, try new things, and don’t be afraid to make mistakes.

Interview with a social insect scientist: Joel Woon

 

Working2 Credit Matt Jarvis

Photo credit: Matt Jarvis

 

IS: Who are you and what do you do?

JW: My name is Joel Shutt Woon, and I have just started a Ph.D. at the University of Liverpool, where I plan to research climatic tolerances of termite communities in Western Africa. However, as with all research projects, the fine details could change! Before this, I studied at Imperial College London for both my BSc in Zoology and MRes in Tropical Forest Ecology.

 

termites are working on tree bark. unite team work  for harmonious working.

Photo credit: Adobe

 

IS: How did you develop an interest in your research?

JW: I was lucky enough to grow up between two large parks in Sheffield, UK, which gave the perfect opportunity to immerse myself in nature. I’d spend hours exploring the forests, searching for insects and amphibians, or following bird calls to try to catch a glimpse of the culprit. This experience growing up developed into a love for the natural world and made my course choice at university very simple. At university, through my BSc and MRes, I found that tropical rainforests were the habitat that enticed me the most. The ability to study your passion in some of the most incredible environments in the world is extraordinary and something that I hope to do for a very long time. I have also discovered, mainly through the course of my MRes work, that I am captivated by entomology, and specifically termites. Their importance as ecosystem engineers, nutrient cyclers, pests, and a food source makes them fascinating to study, and to top it off I think they look charming, although I accept I might be alone in that.

 

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Photo credit: Adobe

 

IS: What is your favorite social insect and why?

JW: There are so many cool termites to choose! Globitermes globosus has a remarkable defensive strategy that involves biting an attacker, locking its jaw, and then secreting a sticky liquid out of its head. This causes the termite to ‘glue’ itself to the attacker (usually a pesky ant), immobilising it and giving time for other soldiers to arrive and workers to repair the nest. Hospitalitermes march through rainforests in groups, similar to army ants, and you can see where they’ve been after they’ve disappeared because all the wood in their path will have been cleared of microepiphytes, leaving a clean trail. Moreover, you have to admire the savannah species of Macrotermesfor the complex and massive nest structures they manage to build.

 

Cordyseps2 Credit Matt Jarvis

Photo credit: Matt Jarvis

 

Away from termites, Camponotus gigas (giant forest ants) are exciting to see around the forest; true gentle giants of the insect world! The size of them blew my mind when I first saw them. I also saw one infected with a cordyceps fungus – seeing a fungus growing out of a giant ant was like witnessing science fiction come to life!

 

african landscape with termitary

Photo credit: Adobe

 

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

JW: I’m still in the fledgling stages of my research career, so I haven’t had many “discoveries”, but finishing my first thermal tolerance experiment was an exciting moment. My supervisor had carried out the same tests on ants, so we started with low expectations of termite thermal tolerance and those expectations were exceeded! Also, walking out into the field to work on my own project for the first time was a huge moment for me. It was the realisation of a goal and a lot of hard work!

IS: Do you teach or do outreach/science communication? How do you incorporate your research into these areas?

JW: I don’t currently do outreach, as I am in the opening week of my Ph.D. as I write this, however, it is something that I want to develop. One of the biggest challenges we face as scientists is communicating our research to a broader audience. We can affect much more significant change if we communicate well than if we keep our work isolated within the scientific community. I think it is an area of science that needs a lot of improvement, and I want to contribute to that improvement.

 

Namibia termite mounds

Photo credit: Adobe

 

IS: What do you think are some of the important current questions in social insect research and what’s essential for future research?

JW: We need to further our understanding of how climate change will impact social insects and increase the power and accuracy of these predictions. Social insects are incredibly important to a myriad of ecosystems, in a plethora of different ways, so understanding how a changing climate will impact their roles within those ecosystems is essential. Will climate change cause species distributions to change? If social insect species are displaced from ecosystems, is there redundancy to cover the lost ecosystem services? How will social insects impact the ecosystems to which they get displaced? These questions remain important.

 

Macro of termites on the forest floor, Borneo, Malaysia

Photo credit: Adobe

 

IS: What research questions generate the biggest debate in social insect research at the moment?

JW: Quantifying and understanding the ecosystem services social insects provide is still a huge topic. Because many species of social insects are massively abundant, they can make huge impacts on ecosystems worldwide. Quantifying those impacts, and what happens to those ecosystems when social insects are excluded, is extremely important. It not only allows us to understand the relative importance of species, but also apply ecological and monetary values to them (regarding ecosystem services and damage caused), which is extremely useful in our modern world.

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

JW: I just finished the Conclave of Shadows saga by Raymond E. Feist, which is the fourth saga set in the fictional world of Midkemia. I would recommend reading Feist’s first book, The Magician, to all fans of fantasy, as it is an excellent and archetypal mythical story that many modern classics borrow from. I’m also reading The Hidden Life of Trees by Peter Wohlleben, which is a fascinating popular science book for people like me who haven’t had much experience in dendrology.

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

JW: My main passion, aside from research, is travelling. I love immersing myself in new cultures, having new experiences, and seeing new environments. Through travelling, I’ve been lucky enough to visit some of the most amazing areas for marine life in the world, which has fostered a passion for scuba diving. Scuba diving is a very surreal and exhilarating experience and one I would recommend everyone try at least once. There is nothing else like it. When I’m back in the UK, my main hobby is playing a card game called Magic: The Gathering. It’s incredibly exciting and complex (it holds the world record for the game with most rules!) and has so much variation while challenging the player to think and strategise well.

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

JW: I think it’s essential to have a dependable support network for you to fall back on. Whether that’s scientific support or emotional support, having people who you can talk to openly and honestly and rely on for help allows you to work through all sorts of issues. I also think you need to have a hobby that you can step away to. Whether it’s for an hour, a day, or a week, you need something that is unrelated to research that you can occupy yourself with, and that will allow you to diffuse any negativity towards your work.

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

JW: I would take an e-reader filled with books (including multiple on how to survive in the wild), a solar charger, and a satellite phone to ring for help when something inevitably goes wrong.

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

JW: As with many biologists of my generation, the person who started me down the path I’m on is Sir David Attenborough. His documentaries opened my eyes to the incredible diversity and majesty of nature and made me want to pursue a career studying it. In a more practical sense, Mike Boyle, my friend and MRes supervisor, has also contributed massively to my development as a scientist, providing invaluable support, advice, and training as well as a healthy dose of realism.

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

JW: Be inquisitive and ask questions, and follow what you find interesting. Scour the internet/ library, go bug hunting in a garden, or contact experts! Most scientists love to share their research; whether you’re a grade school student or undergraduate, an amateur or a professional – if you reach out to people in your community, it is incredibly likely that you will get a response and tap into a source of knowledge that you wouldn’t otherwise be able to access. So send an email or two, ask a few questions, and see where it takes you!

Honey Bee Immunity: More Specific than We Thought

A blog post highlighting the article by N. Wilson-Rich, R. E. Bonoan, E. Taylor, L. Lwanga, and P. T. Starks in Insectes Sociaux

By Rachael E. Bonoan and Philip T. Starks

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Nature can be hostile, especially for insects — tiny creatures that deal with big problems. They get eaten, they dry out, they get smashed. Believe it or not, insects also deal with even tinier pests and pathogens, just as we do.

Also, like us, insects have developed an immune system to combat such microscopic threats. Over the years, scientists have uncovered how insect immunity relates to behavior, mating success, ability to find food, nutrition, energy cost, etc. However, the method used to study insect immunity — sterile fishing line inserted through the membrane between the sclerites — does not reflect the evolutionary history of insects and their pathogens. In our recent paper, we describe a modified method to investigate insect immune strength and its specificity. We show that the insect immune system may be able to recognize different classes of pathogens and respond accordingly.

An insect’s first line of defense is a physical barrier: the exoskeleton. When the exoskeleton is injured, however, diverse pathogens can invade. Once a pathogen makes it past this barrier, the insect immune system uses proteins called pattern recognition receptors (PRRs) to recognize cellular patterns on the invader (pathogen-associated molecular patterns, PAMPs). One of the many responses the immune system can then carry out is the encapsulation response (ER) where the invader is surrounded by immune cells which secrete a protein, melanin, that detoxifies the invader.

The strength of insect ER is typically measured by inserting a piece of sterile fishing line into the insect, waiting for the immune system to respond, and then removing the fishing line “invader.” Researchers then use light microscopy to measure how much melanin (i.e., color) developed on the fishing line. The darker the explanted fishing line, the more melanin deposited, and thus, the stronger the immune response. While the fishing line does mimic a physical injury, it does not mimic the diverse pathogens with which insects have evolved.

To make this method more evolutionarily relevant, we added a layer to the typical method: PAMPs. Different pathogens have different patterns (PAMPs) on their surface that the host PRRs recognize. We tested honey bee ER in response to fishing line coated in PAMPs found on two types of bacteria and fungi. We call our modified fishing line implants PAMPlants.

Once we coated the PAMPlants, we carefully inserted them between two segments of the honey bee exoskeleton. This is truly a labor of love. Handling the coated fishing line (2mm long, 0.4mm diameter—tiny!) with forceps takes steady hands and attention to detail. Thankfully, two NSF Research Experience for Undergraduate fellows were around to help carry out this mini-surgery on the 176 bees it took for this study! To let ER happen, we left both uncoated implants and coated PAMPlants in the honey bee for 4 hours. We then carefully removed all implants, and prepared a microscope slide with the explant. Microscopy was used to take images of the explant. We analyzed the images for color (i.e., melanin) as the typical proxy for ER strength.

Compared with a control implant (fishing line coated in phosphate-buffered saline), honey bees had a stronger ER to PAMPlants. In honey bees implanted with both a control implant and a PAMPlant, fungal PAMPlants and one of the bacterial PAMPlants (lipopolysaccharide) lead to a stronger ER than the control implant.

With this modified method, we show variation in honey bee immunity in response to different classes of pathogens. Since we saw an increase in ER for fungal and one of the bacterial PAMPlants, it is likely that physiological immunity is important for fighting these types of pathogens in honey bees. We did not see similar results for our third PAMPlant (peptidoglycan) which is found on some bacteria. In agreement with our results, honey bees likely combat this specific type of bacterial infection behaviorally rather than physiologically (Spivak and Reuter 2001).

When it comes to dealing with pests and pathogens, honey bees have it especially hard. In keeping bees, humans have unwittingly facilitated the spread of honey bee disease. In commercially raising bees, we have increased the density of honey bees across the landscape, and in some cases, we nurse weak colonies which are more likely to spread such disease.

The most notorious honey bee pest is the Varroa mite. This mite is the honey bee’s version of a tick. Ticks spread diseases in humans by puncturing our protective barrier (i.e., skin) and feeding on our blood. Varroa mites spread disease by injuring the honey bee’s physical barrier and feeding on the bee’s fat body—an essential organ for energy storage and immunity (Burnham 2018; Kielmanowicz et al. 2015).

Our modified method suggests that uncoated implants (i.e., fishing line) may not give insect immunity enough credit. While we have learned a lot about insect immunity with uncoated fishing line, we have so much more to uncover with PAMPlants!

References

Burnham T (2018) Downtown new hope in the fight against Varroa. Bee Culture, A.I. Root Company, Medina, OH, USA

Kielmanowicz MG et al. (2015) Prospective large-scale field study generates predictive model identifying major contributors to colony losses PLoS Pathog 11:e1004816 doi:10.1371/journal.ppat.1004816

Spivak M, Reuter GS (2001) Resistance to American foulbrood disease by honey bee colonies Apis mellifera bred for hygienic behavior Apidologie 32:555-565