By Crystal Ernst, PhD Candidate (McGill University)

Since I finally submitted my manuscript to a journal (YAY!), I’ve been tying up the little loose ends remaining at the end of the project. You know: organizing the useful data and image files, tossing the files marked “MESSING_AROUND_WITH_DATA_v.29), tidying up my R code, and, perhaps most importantly, curating my specimens.

I’m not going to go into too much detail about the project here (I’m saving that for another post). I will say, though, that the work I just completed includes just over 2,600 beetles from a single location in Nunavut (Kugluktuk, where I spent my entire first field season).

Two major aspects of the physical work (as opposed to the thinking, reading and writing) involved in an ecological/entomological project such as this one are the pinning and the identifications. Some of the tasks are a bit tedious (cutting labels; entering data; gluing over 800 specimens of the same tiny, plain black ground beetle to paper points), and some of them are thrilling (finally getting over the “hump” of the morphological learning curve and feeling good and confident when working with your keys; having experts tell you “Yep, you got those all right”; discovering rare species or new regional species records). In the end, in addition to the published (*knocks on wood*) paper, you have boxes or drawers full of specimens.

The specimens are gold. (Read this post by Dr. Terry Wheeler to understand why.)

Unfortunately, they don’t always get treated as such.

In the two-ish years that I’ve been working in my lab, we’ve had two major “lab clean-up days”. The first managed to get rid of a lot of clutter (old papers, broken apparatus, random crap). The second involved going through the “stuff” that was eating up all the most valuable storage space: specimens. Years and years worth of graduate and undergraduate projects’ specimens, stashed in freezers, boxes, bags and vials of all shapes and sizes.

Some things were in good shape (pinned well, or in clear ethanol). Other things were, well, downright nasty: gooey beetles in sludgy brown ethanol, dried up bits of moth wings in plastic containers, and a little bit of “what in the name of pearl is growing on that agar plate???” in the fridge.

None of these items were kept – their value as useful specimens was nil. So, the physical representation of some student’s work – probably months or years worth of work – was tossed in the trash.

Others, happily, were tucked back into drawers and cupboards, because someone had taken the time to ensure the specimens were well-preserved.

However, even many of these were suffering from a serious issue: bad labels.

Allow me to illustrate the point. This is a bad label:

This is also a bad label:

The first, you’ll note, is written in ballpoint pen (which fades) on a torn piece of notebook paper and contains almost no information. The second, although it looks fancier and perhaps more sciencey, is just as bad: it contains a cryptic code that is useful only to the bearer of the lab notebook in which said code has been written down. Or, perhaps the code is completely intelligible to the researcher who developed it, but the key to it exists only in his or her head.

To everyone else, it is meaningless. Neither of these labels indicate who collected the specimen, where, when, or how. And we all know what happens in labs: upon completion of their degrees, students move on, email addresses change, notebooks are misplaced, data files are not backed up. The labels’ codes can never be broken, and the scientific value of the specimens – *poof*.

While there’s nothing wrong, in theory, with using labels like these temporarily (although there is always a risk that they will be misinterpreted or misunderstood after a little while, even by the person who wrote them), they are absolutely useless as permanent records.

These are good labels:

These labels, properly affixed to a specimen, provide clear and universally understood information. One provides the location, including GPS coordinates, a method of collection, a date, the name of the collector(s). The information that goes on this label can vary a bit (it may include information about the habitat or host plant, for example), but those are the basic requirements. The smaller label is typically affixed on the pin below the first, and contains the specimen’s scientific name and the name of the person who identified it (it is the “det. label”, i.e., “determined by”). These labels, and therefore the specimen with which they are associated, will remain useful for decades, even centuries.

I am totally guilty of both of the offenses I just explained (the gooky vials of nastiness and the bad labels). For my undergraduate honors project, I identified close to 8000 spiders, mites and insects to the Family level – it was hundreds of hours of microscope work. Then I stuffed all those specimens back into vials with cryptic little codes, like V-1-F(!), hand-written on STICKERS(!), which I placed on the LIDS(!) and not even in the vials themselves(!). Oh, and I’ve long since lost the notebook that contained my decoder key(!). THIS IS ALL SO BAD. I have no doubt that those boxes of vials, which I once prized so highly and felt such pride for, have been unceremoniously tossed in the trash by my former advisor.

Well, I’ve learned from my mistakes, and from working with museum and other collection specimens. I now understand that each specimen is deserving of respect – it’s the original data after all – and that means it should be properly preserved, and labelled.


Last week I spent a great deal of time, as I said, tying up my loose ends. The last thing I needed to do was remove my cryptic labels (the second in the series up there is an actual example of one of my own “secret code” labels) and replace them with proper ones, sorting and tidying up the collection in the process. The end result?


Frankly, it’s a thing of beauty. It’s also enormously scientifically valuable. These specimens will be deposited in various nationally-important collections and museums, like the CNC.

As a matter of fact, just last week I was at the CNC, and I saw specimens bearing the name of the last person to do a comprehensive survey of the insects in Kugluktuk, back in 1955. That tiny but so-important label suddenly made me feel connected to the man who, almost 60 years earlier, had stood on the same stretch of tundra as me, holding and perhaps delighting in the very specimen that I held in my own hand.

Giving my specimens the respect they deserve is worth it, not only for the scientific value, but also because perhaps, 60 years from now, another grad student will discover my name on a specimen’s det. label. Perhaps she, too, will feel that same wondrous sense of connection to the the greater scheme of scientific discovery…

Original post at:

(Note: the English version follows)

Guillaume Dury, Étudiant à la maîtrise, Université McGill

Dessous de Chrysiridia rhipheus, photo par Cody Hough sur Wikimedia Commons.

Le 7 avril 2012, l’article du jour sur Wikipédia était Chrysiridia rhipheus.

C’était un grand jour pour moi : j’ai écrit la majorité de l’article. Ce n’est pas pour autant mon article; dire cela irait à l’encontre de l’étiquette de Wikipédia. J’y ai tout de même passé des heures de recherche et j’ai écrit la majorité de l’article.

Tout comme des millions de personnes, j’utilise Wikipédia pour étancher ma soif de connaissances rapides. À juste titre, “«wiki»” est Hawaïen pour rapide. Seulement, il n’y avait pas de wiki-connaissances sur ce papillon de nuit qu’est l’Uranie riphée (Chrysiridia rhipheus).

J’étais toujours curieux; cette soif particulière ne resterait pas inassouvie. Puisque j’allais faire une recherche de littérature, aussi bien écrire un résumé au bénéfice des autres. Voilà comment je suis devenu un éditeur sur Wikipédia.

J’ai créé l’article le 5 août 2006, un peu avant de commencer mon baccalauréat en biologie. En tant que biologiste de formation, j’avais besoin de pratiquer les tâches concernées dans l’écriture de l’article. Le plus important fut de trouver l’information. J’ai pu trouver beaucoup d’information en ligne : dans les articles scientifiques et dans des livres numérisés par Google Books ou Internet Archive. J’ai aussi appris que, parfois, des références ne sont tout simplement pas disponibles en ligne. C’est alors que j’ai utilisé les prêts entre bibliothèques pour la première fois. Peu a peu, une référence à la fois, j’ai rempli les différentes sections de l’article.

La partie sur la taxonomie et la description de l’espèce fut beaucoup plus intéressante à écrire que je l’aurais cru. L’Uranie rhiphée, ou le “«papillon coucher de soleil malgache»” (de l’anglais “Madagascan sunset moth”) a toute une histoire derrière ses noms. Il est décrit pour la première fois, en 1773, sous le nom de Papilio rhipheus. C’est-à-dire qu’il avait été placé parmi les papillons de jour et non de nuit. Capitaine May de Hammersmith avait donné le spécimen à l’entomologiste britannique Dru Drury. Ce spécimen avait été “«réparé»” avec une tête de papillon de jour et ses antennes en massue. (NB : ne pas coller la mauvaise tête sur votre spécimen cassé!) En 1831, René Primevère Lesson l’avait décrit sous le nom Urania ripheus var. madagascarensis. Ce papillon a toujours plusieurs autres synonymes.

En utilisant les guides sur Wikipédia, en demandant d’autres éditeurs et en m’inspirant de d’autres articles, j’ai rassemblé et résumé de plus en plus d’information. J’ai fait passer l’article par le processus interne d’évaluation par les pairs dans Wikipédia en janvier 2007. Sur Wikipédia, les pairs sont d’autres éditeurs et pas nécessairement des entomologistes. Cela a aidé un peu, surtout pour le format article, mais je devais surtout trouver d’autres sources d’information à inclure.

Puis, j’ai contacté l’un des experts mondiaux sur Chrysiridia rhipheus, le Dr David C. Lees du Musée d’Histoire naturelle de Londres. J’ai été agréablement surpris; il était déjà éditeur sur Wikipédia. Il m’a dirigé vers des références importantes que j’avais manquées et a ajouté des informations lui-même. J’étais ravi.

Carte de cigarettes dépeignant une fée « Chrysiridia madagascariensis » en 1928, compagnie John Player & Sons.

En mars 2008, je jugeais que mon article avait atteint le niveau de “«bon article»”. Pour être reconnu comme tel, un article doit répondre à certains critères et passer avec succès le processus de mise en candidature de bon article. Avec l’examen et des suggestions de l’utilisateur Casliber, c’est ce qui s’est passé le 22 mars 2008 : j’avais écrit un “«bon»” article sur Wikipédia.

J’ai continué; j’ai fait des modifications, j’ai ajouté des références, des images, y compris une carte de cigarettes datant de 1928, et j’ai ajouté ce qui est probablement la seule photo de la chenille de cette espèce sur Internet. J’ai eu l’aide de l’un des principaux éditeurs des articles sur l’optique et la polarisation des articles afin de clarifier pour moi la polarisation de la lumière. Les écailles sur les ailes du papillon produisent les couleurs à travers deux phénomènes optiques, l’un dépend de polarisation. Le papillon ne dispose de pigment que dans les régions noires de ses ailes.

Ensuite, le 18 juin 2008, j’ai fait la mise en candidature de l’article pour qu’il soit reconnu comme article de qualité. Les articles de qualité sont considérés comme représentant le meilleur de ce que Wikipédia a à offrir, comme déterminé par les éditeurs de Wikipédia. Lors de ce processus, de nombreux éditeurs font des suggestions et demandent des changements à l’article. J’ai fait la plupart de ces changements et fait de mon mieux pour répondre aux questions. Le 4 juillet 2008, Chrysiridia rhipheus a été promu au statut d’article de qualité. Featured article en anglais; ce statut exceptionnel est signifié par une petite étoile dans le coin supérieur à droit! :

En moyenne, l’article Chrysiridia rhipheus est visité à peu près une centaine de fois par jour. Le 7 avril 2012, il a été visité plus de 20 000 fois. Au cours des 90 derniers jours, cela fait un total de 37614 fois. C’est de la bonne diffusion!

Je répondrai avec plaisir aux questions de ceux qui s’intéressent à l’écriture de « leur propre » article Wikipédia. Tout commence par le bouton [modifier]…

Pour les professeurs : “«dans le cours ENTO 431 entomologie médico-légale, à l’université du Texas A & M, les étudiants ont la tâche d’écrire plusieurs articles sur Wikipédia concernant les espèces de mouches d’importance médico-légale.»” Le travail des étudiants sert alors leur cours et sert le but de Wikipédia de créer un résumé de toutes les connaissances humaines dans une encyclopédie libre et en ligne. (Pour plus d’informations, voir la page du cours sur Wikipédia (en anglais))


By Guillaume Dury, M.Sc. student, McGill University

Engraving captioned Urania riphaeus from Charles D. d’Orbigny’s Dictionnaire universel d’histoire naturelle (1849)

On April 7th 2012, on Wikipedia, Today’s Featured Article was Chrysiridia rhipheus.

It was an exciting day for me: I wrote most of the article. It isn’t my article; it would be against Wikipedia etiquette to say so. Still, I spent hours researching and wrote most of it.

Just like millions of people, I use Wikipedia to quench my thirst for quick knowledge. Appropriately, “wiki” is Hawaiian for quick. Only there was no wiki-knowledge on the Madagascan sunset moth (Chrysiridia rhipheus).

I was still curious; this particular thirst wouldn’t be left unquenched. Since I would search the literature, I thought I might as well write a summary for the benefit of others. That is how I became an editor on Wikipedia.

I created the article on August 5th 2006, a little before starting my bachelor’s in biology. As a biologist in training, I needed to practice the tasks involved, most importantly: finding information. I was able to find a lot online: in scientific articles and scanned books in Google Books or Internet Archives. I also learned that sometimes, references are simply not available online. That is when I used interlibrary loans for the first time. Little by little, one reference at a time, I filled the different sections of the article.

The section on taxonomy and naming of the species was a lot more interesting to write than I initially thought it would be. The Madagascan sunset moth has quite a story behind its names. It was first described, in 1773, as Papilio rhipheus. That is to say, it was described as a butterfly and not a moth. Captain May of the Hammersmith gave the specimen to the British entomologist Dru Drury, only that specimen had been “repaired” with a butterfly head that had clubbed antennae. (N.B.: don’t glue the wrong head on your broken insect specimen!) In 1831, René Primevère Lesson described Urania ripheus var. madagascarensis. The moth also has a number of other junior synonyms.

Using guides on Wikipedia, asking other editors and inspiring myself with other articles, I gathered and summarized more and more information. I went through Wikipedia’s internal process of peer review in January 2007. On Wikipedia, peers are other Wikipedia editors, not necessarily entomologists. This helped somewhat, especially for article format, but I really had to look for more sources and information to include.

I contacted one of the world experts on the Madagascan sunset moth, Dr. David C. Lees of the London Natural History Museum. I was pleasantly surprised he was already an editor on Wikipedia. He pointed me towards important references I had missed and added information himself. I was delighted.

A cigarette card featuring a “Chrysiridia madagascariensis” fairy in 1928 from John Player & Sons.

In March 2008, I felt my article was close to the level of “Good article”. To be recognized as such, an article needs to meet the good article criteria and to successfully pass the good article nomination process. With the review and suggestions of user Casliber, this happened on March 22nd 2008: I had written a “Good” article on Wikipedia.

I kept going, did more editing, added references and pictures, including a cigarette card from 1928, and what is probably the only photo of this species’ caterpillar on the Internet. I got help from one of the main editor of the articles Optics and Polarization to clarify light polarization for me. The scales on the moth’s wings use two optical phenomena to produce the colours, one of which is polarization dependent. The moth only has pigment in the black regions of its wings.

On June 18th 2008, I proposed the article for evaluation to be recognized as Featured. Featured articles are considered to be the best Wikipedia has to offer, as determined by Wikipedia’s editors. In this review process, various editors make suggestions and ask for changes to the article. I made most of those changes and answered questions to the best of my knowledge. On July 4th 2008, Chrysiridia rhipheus was promoted to Featured Article, this exceptional status is signified by a little star in the top-right corner!:

On an average day, the article Chrysiridia rhipheus is viewed roughly a hundred times. On April 7th 2012, it was viewed over 20 000 times. In the last 90 days, that makes a total of 37 614 times. Good exposure!

I’ll happily answer the questions of anyone interested in writing “their own” Wikipedia article. It all start with the [edit] button…

Lastly, a note for the professors: “As a part of the ENTO 431, forensic entomology course at Texas A&M University students are assigned the task of writing several articles at Wikipedia pertaining to forensically important fly species.” The students’ work serves their course, and Wikipedia’s goal to create a summary of all human knowledge in an online encyclopedia. (For more information see the course’s Wikipedia page)

Stick Insect Baculum extradentatum

Physiology Friday is a monthly column by UWO PhD candidate Katie Marshall and will feature new Canadian research on insect physiology.


Nitric oxide (NO) is usually overshadowed in fame by its more famous cousin laughing gas, but it’s difficult to think of many simple molecules that have such a variety of important biological functions.  While NO only lasts a few seconds in the free gaseous state in the blood, it has been implicated in processes that involve everything from immune function to neurotransmission.  One important role for NO is in the cardiac system, where it functions as a vasodilator and in vertebrates it slows heart rate, while in insects it has the opposite effect.

Stick Insect Baculum extradentatum

Baculum extradentatum photo by Sara da Silva

Most of the research about the physiological functions of NO has focused on vertebrates, but recent work published in the journal of Cellular Signalling by graduate student Sara da Silva and her postdoctoral fellow mentor Rosa da Silva in the lab of Angela Lange (University of Toronto Mississauga), has shown that, unlike other insects, the Vietnamese stick insect Baculum extradentatum can respond to NO like a vertebrate.

“Our initial research interests in cardiac physiology were influenced by earlier work indicating that stick insect hearts are innervated and can be modulated by endogenous chemicals [like NO],” says study director and University of Toronto Biology professor Angela Lange.  “It is for this reason that we chose this understudied organism, which contains a simplified cardiovascular system that can be considered a model for work on other cardiac systems.”

The researchers first attempted to find the natural source of NO in the stick insect by removing hemolymph (blood) samples and staining for the presence of an enzyme that produces NO.  Then they examined the effects of NO on heart rate by dissecting the dorsal vessel out and maintaining it in a Petri dish with physiological saline.  They could measure heart rate through the placement of electrodes on either side of the dissected heart, and monitor the effects of various chemicals on the cardiac activity of the stick insect.   They also could examine whether heart rate was mediated by the central nervous system by leaving the nervous system attached or not.

insect heart rate

The effects of nitric oxide on the heart rate of B. extradentatum. Figure 3 from da Silva et al. 2012

They found that the hemocytes (blood cells) of the stick insect were producing an enzyme that was similar to the enzyme other animals use to produce NO.  In addition, the more of a chemical called MAHMA-NONOate (which produces NO) they added, the slower the stick insect hearts beat.  This surprising effect was completely opposite to what had been found in other insects and was more like the response of the vertebrate heart.

“Insects have evolved different strategies depending upon life history, and have co-opted different messenger systems for this success,” says study author da Silva. “We need to understand the full ecology of all species to finally appreciate the factors involved.”

Using the same setup, they also tested other components of a system of compounds that they thought might be involved in the pathway that produces NO that leads to decreased heart rate in B. extradentatum.  They believe that NO is produced in the hemocytes, travels to the wall of the heart, and then leads to the production of a messenger molecule that decreases heart rate.

Schematic diagram of the proposed regulation of cardiac activity in B. extradentatum by the gaseous signaling molecule, nitric oxide (NO)

Schematic diagram of the proposed regulation of cardiac activity in B. extradentatum by the gaseous signaling molecule, nitric oxide (NO). Figure 7 from da Silva et al. 2012.

“This study further emphasizes the evolutionary links between the physiological processes of vertebrate and invertebrate systems,” says da Silva. “Our findings suggest that signaling molecules (such as NO) common to both types of organisms can have similar effects on cardiac activity.  These novel findings demonstrate that the study of vertebrate systems can be complemented with studies in model invertebrate organisms.”

da Silva, R., da Silva, S.R. & Lange, A.B. (2012). The regulation of cardiac activity by nitric oxide (NO) in the Vietnamese stick insect, Baculum extradentatum, Cellular Signalling, 24 (6) 1350. DOI: 10.1016/j.cellsig.2012.01.010

My name is Chris Buddle – I’m an Associate Professor at McGill University, in Quebec, Canada, and the Editor-in-Chief for The Canadian Entomologist. I have worked at McGill University, in the Department of Natural Resource Sciences, for about 10 years. As a Professor, my work involves all three aspects of academia – teaching, research, and service.

For teaching, I instruct undergraduate courses in our “Environmental Biology” program – this involves teaching courses in both my own area of expertise (entomology) as well as in more general areas (e.g., ecology).

My research program is quite varied; although originally hired as a “Forest Insect Ecologist” my research expertise is broader than that, and I currently oversee graduate students working on insect pest management, the ecology of herbivorous insects in forest canopies, and the biodiversity of Arctic arthropods. The latter initiative is part of a larger-scale project titled the Northern Biodiversity Program.

For “service” I devote a lot of time and energy into my position as the Editor-in-Chief for the Entomological Society of Canada’s flagship journal The Canadian Entomologist (TCE) – a journal that joined a publishing partnership with Cambridge University Press in January of this year.

TCE is an excellent scientific journal, and I am honoured to be associated with it. Its excellence is in part because of TCE’s long history as an internationally renowned entomology journal – it has been published continuously since 1868. TCE is a journal with particularly high editorial and technical standards. We pride ourselves on serving authors well, and on producing a product that has been carefully edited, and that is technically clean. TCE is one of the relatively rare entomology journals that publishes on all facets of the discipline, including taxonomy and systematics, biodiversity and evolution, insect pest management, behaviour and ecology, and more.

We are, therefore, an entomology journal for all entomologists – anyone interested in arthropods can generally find an article of relevance within its pages. I’m also excited about TCE’s new partnership with Cambridge. This publishing house has an equally impressive history, and an equally high standard of publication quality. With this partnership, authors no longer pay page charges for TCE, and receive a complementary PDF of their articles.

As Editor-in-Chief, I have an opportunity to help guide the journal into the future. My editorial objectives include a balance of doing what we have done well in the past (i.e., high quality standards), but also seeking some new opportunities. For example we are initiating a plan to produce a topical “special issue” of TCE every year, for the first issue of each volume. For Volume 145 (the year 2013), we will be devoting an entire issue to the topic of “Perspectives on Arctic Arthropods“. This is an extremely important area of study given the current global concerns about changing climates, especially since some of the effects will be most acute in polar regions. The call for papers for this special issue went out at the end of January, and authors have until 15 June 2012 to submit their manuscripts.

Another objective I have is to continually improve our service to authors. Our move to an on-line manuscript submission system is helping this tremendously and I am continuing to work with my editorial team to tweak the system for the benefit of our authors. I am also interested in bringing entomology, and TCE, to a broader audience. Entomology is a vast and wonderful discipline, but the pages of entomology journals often target a specialized audience. I think a lot of what we publish in the journal is of broad interest, and for that reason, I tweet for the Entomological Society of Canada’s twitter account (follow us: @CanEntomologist). This is an effective way to use social media to highlight articles we publish, activities of the Entomological Society of Canada, and other interesting entomology events and stories. We also have plans to work with our society to develop a blog devoted to entomology in Canada, and TCE will be featured prominently on this blog.

I would like to conclude with a few words of advice for up-and-coming entomologists looking to publish their work. The publication ‘game’ can be a complex one, and it is a changing landscape that can be difficult to navigate. In addition to thinking about the traditional metrics when considering different journals, I do recommend that all potential authors look carefully at the “aims and scope” section for potential venues for publication – it is important that your work will be a good fit with the journal. It’s also easy to be swayed by numerous journals that are sprouting up and seem to be offering everything for nothing. Some journals may seem attractive at first glance, but be aware that quality of service, and the quality of the editorial process, may be less than what could be offered by journals backed by a publisher with strong credentials. More ‘traditional’ journals often have an incredible amount of behind-the-scenes support, and this matters. I will also stress that all authors must strive for a clean, concise, and well-written manuscript. I cannot state strongly enough that careful writing and proofreading is of paramount importance.

In sum, it’s truly a delight to be associated with The Canadian Entomologist and its publication partner, Cambridge University Press. The future is bright for the journal, and I am exciting to work hard to increase the profile and readership of TCE, all the while maintaining its history of excellence. I have assembled a strong editorial team of 20 subject editors, and have additional support from my Editorial Assistant, Dr. Andrew Smith. We are all here to help you publish your best entomological research, and get it into the hands of an international audience.

Read the first issue of the year for free here


This article was originally published at and can be found at:

By Michel Cusson, ESC President

For my first blog post, you’d probably expect me to talk about some hot issue pertaining to the ESC. However, I chose otherwise (at least this time) and I’ll save Society-related topics for my “Up Front” column, which you can read in the online version of the Bulletin. Instead, I’d like to introduce you to what I consider the coolest product of insect evolution: the use of symbiotic viruses by parasitic wasps to manipulate the physiology of their caterpillar hosts.

Aleiodes indiscretus wasp parasitizing a gypsy moth caterpillar. Photo by Scott Bauer.

In an unusual twist of evolutionary history, some ichneumonid and braconid parasitoids have “captured” a conventional virus and “domesticated” it so that it can be used to their own advantage in the course of parasitism. The viruses in question, known as polydnaviruses (from poly-DNA-virus, but typically pronounced “polyd-na-virus”), replicate in wasp ovaries where they accumulate in the fluid bathing the eggs, before being injected into the caterpillar during parasitization (egg laying). While the carrier wasp is completely asymptomatic, the infected caterpillar displays AIDS-like symptoms, whereby its ability to mount an immune response against the wasp egg or larva is depressed by the virus. In addition, the virus will often block host metamorphosis, particularly when parasitization takes place late in caterpillar development; this will allow the wasp larva to complete its own development before the host undergoes the traumatic events associated with the larva-to-adult transformation.

But what makes these viruses pathogenic in the caterpillar while being apparently harmless in the wasp, and how could such unusual creatures have evolved? To begin understanding the answers to these questions one first needs to know that polydnavirus genomes are permanently integrated into the chromosomal DNA of the carrier wasps. This means that all individuals within a species known to carry one of these viruses contain the viral DNA within their own genome. Production of the viral particles, however, is confined to females and occurs only in ovaries. There, copies of the integrated form of the viral genome are synthesized and packaged into a proteinacious coat known as the “capsid”. These viral particles are released into the lumen of the oviduct, where they accumulate until injection into the caterpillar host.

What’s going on “behind the scenes”. Image by Michel Cusson and Marlene Laforge.

Once injected, the virus gains access to various host tissues where some of its genes are expressed, leading to the synthesis of viral proteins that do the dirty work, i.e., depress the host immune response and perturb host development. Few, if any, of these virulence genes are expressed in the wasp, which probably explains why the wasp is asymptomatic. While the virus does not replicate in the caterpillar, it is the expression of viral genes that makes it possible for the wasp egg and larva to survive within the host. And successful development of the immature wasp is what ensures transmission of the integrated form of the virus to the next wasp generation.

Whether polydnaviruses are “real” viruses has been a matter of debate for many years. For example, some have argued that, although they look like viruses, they are nothing more than a smart device that the wasps have evolved to transfer host-regulating factors to caterpillars during oviposition. However, it is becoming increasingly clear that polydnaviruses arose from ‘conventional’ viruses.

Recently, a group from France has shown that the proteins that make up the coat of braconid polydnavirus particles are highly similar to those of ‘nudiviruses’1, a group of conventional insect viruses that are capable of integrating their genomes into those of their hosts. So, it appears that the genome of a nudivirus became permanently integrated into the chromosomal DNA of an ancestral braconid, some 100 MYA. Since then, evolution has led to the replacement of the original nudiviral virulence genes by other genes that are usefull to the wasp during parasitism. The wasps may therefore be viewed as having ‘domesticated’ the nudivirus, turning it into a mutualistic virus – a phenomenon fairly unique in the world of viruses. Cool stuff, isn’t it?

This post was chosen as an Editor's Selection for ResearchBlogging.org1Bezier, A., Annaheim, M., Herbiniere, J., Wetterwald, C., Gyapay, G., Bernard-Samain, S., Wincker, P., Roditi, I., Heller, M., Belghazi, M. & (2009). Polydnaviruses of Braconid Wasps Derive from an Ancestral Nudivirus, Science, 323 (5916) 930. DOI: 10.1126/science.1166788