Category Archives: Deliverables

What’s in a name? A previously unrecognized species of North American black fly from Baffin Island

Biting flies are a scourge at northern latitudes. Nearly every early explorer made reference to the tenacity and voracity of these tiny insects. Not surprisingly, biting flies reach their peak abundances in northern environments, with mosquito densities reaching a staggering 12.5 million individuals per hectare in the Hudson Bay Lowlands. Similarly, black fly larvae can reach densities of 1.2 million per square meter of stream substrate under optimal conditions. Given their abundances, and economic importance (through blood feeding and transmission of parasitic diseases), it is not surprising that biting flies are among the best known insects in North America.

Black flies are an especially well known as they were the subject of a monumental revision of the North American simuliid fauna by Adler et al. (2004).  In fact, no new North American species have been described since that book was published 9 years ago. Consequently, I was amazed to discover a hitherto unknown species near Iqaluit, NU on southern Baffin Island (Figure 1). It is a member of the circumpolar genus Stegopterna (Enderlein 1930) which includes 8 North American species.  However, only one species — St. emergens (Stone 1952) — is known to be distributed widely at northern latitudes.

This previously unknown species was overlooked during initial sorting and counting. However, subsequent DNA barcoding, revealed >10% sequence divergence between this species and Stegopterna emergens, the species it was initially mistaken for. This prompted a closer examination of the morphology of the Iqaluit population, which differed from St. emergens in 2 important ways. The first relates to the length of the pupal gill trunk (Figure 2). Pupal gills are often used for species level identification of black flies, and this difference was consistent in all specimens examined. However, a more striking and ecologically significant difference is that the Iqaluit species has mouthparts adapted for blood feeding. Distributional records reveal that, of the 9 black fly species previously recorded from the Canadian Arctic Archipelago, only 2 had biting mouthparts. The other species were arctic-adapted (i.e., non-bloodsucking) species that use nutrients from their larval stages to develop their eggs. Interestingly, the two biting species were both found only on southernmost Baffin Island.

The discovery of this previously unknown species of bloodsucking black fly raises important ecological and evolutionary questions. Historical records suggest that St. emergens was present on southern Baffin Island during the 1950s; however, contemporary collections yielded only this previously unrecognized one. Were historically collected specimens simply mistaken for this undescribed species, or was St. emergens supplanted by this new one on southern Baffin Island? Reexamination of historically collected material in the Canadian National Collection of Insects is needed to select from these alternative hypotheses. DNA barcoding may again prove useful should the diagnostic life stages (i.e., adult females, pupae) prove unavailable for study.

Another important question is why southern Baffin Island was the only region in the Canadian Arctic Archipelago to historically support bloodsucking black flies. The recent discovery of yet another blood feeding species on the Island (Schaefer 2011) further reinforces the suitability of conditions for this feeding habit. A more favorable climatic regime seems a likely explanation; however, further analyses are required.

Finally, this undescribed species was not present at any other Arctic or Boreal site sampled by the NBP. This raises the question of how widely distributed this species is. There have been no records of morphological or chromosomal differences between mainland and continental island populations, nor have any continental island endemic black flies have ever been found in North America. This makes it extremely unlikely that this new species is restricted to Baffin Island and suggests its distribution likely extends southward into northern Quebec or westward across Nunavut (albeit in potentially low numbers).

The process of assigning a name to this previously unrecognized species is not particularly straightforward. While it’s possible that the southern Baffin Island Stegopterna is an undescribed (i.e., is a new to science) species, we can’t rule out the possibility that it’s actually a Holarctic species that already carries a valid scientific name.  Unfortunately, Stegopterna species are notoriously difficult to identify morphologically, and there are at least 7 candidate names to consider from the northern Palearctic Region (all members of the St. trigonium species complex). We must now begin the process of poring over species descriptions to determine whether any of the available names could reasonably be applied to the southern Baffin Island population. But however this exercise turns out, it’s gratifying to know that there are still new and exciting discoveries to be made in northern Canada.

References

Adler, P.H., D.C. Currie and D.M. Wood. 2004. The Black Flies (Simuliidae) of North America. Cornell University Press. Ithaca, NY.

Schaefer, P. 2011. Update on the biting fly component (Diptera: Simuliidae, Culicidae and Tabanidae) of the Northern Biodiversity Program. Newsletter of the Biological Society of Canada 30: 41-49.

It’s a wrap! How about a thesis on Arctic spiders? How about two of them…?

By Dr. Christopher Buddle

This week I am thrilled to report that two of my MSc students have successfully completed their degrees! Both the projects are part of the collaborative Northern Biodiversity Program – a project aimed to quantify and understand ecological change with Arthropods from Canada’s north.

A BIG congratulations to Sarah Loboda and Katie Sim  – they are both tremendously talented students, excellent Arachnologists, and wonderful people to know.  Last night we had our annual Lab BBQ – and at that event, I was pleased to give Sarah and Katie a small token of appreciation.  Here’s a photo showing them both with their wolf spider photographs (photos by the incredible Thomas Shahan):

Katie Sim (l) and Sarah Loboda (r) - successful MSc students!

Katie Sim (left) and Sarah Loboda (right) – successful (& happy) MSc students!

Sarah Loboda’s thesis is titled Multi-scale patterns of ground-dwelling spider (Araneae) diversity in northern Canada. Her research focused on broad diversity patterns of ground-dwelling spiders collected from our 12 study sites, spread across Canada’s north. Our project spanned 30 degrees of latitude and 80 degrees of longitude –> yes that is a lot of land area! Sarah identified over 300 spider species from 14 families, and over 23,000 individuals.  Publications are forthcoming so I won’t give details here, except to say that we can learn a lot about diversity patterns over broad spatial scales using a study taxon such as spiders.

Here's where the Northern Biodiversity Program took our field teams!

Here’s where the Northern Biodiversity Program took our field teams.

Katie’s work (co-supervised by Prof. Terry Wheeler) had a different slant, but was still on Arctic spiders. Her thesis is titled:  Genetic analysis of Pardosa wolf spiders (Araneae: Lycosidae) across the northern Nearctic. The first part of Katie’s thesis was about understanding the phylogeographic history of the Arctic spider Pardosa glacialis, with particular attention to post-glacial dispersal patterns, as inferred by population genetics. The second part of her thesis was focused on whether or not there is enough evidence to suggest two northern Pardosa species should remain as separate species, or be merged into one – based on both molecular and morphological characters.  Let’s just say that Katie had to be a ‘field genius‘, ‘lab genius‘ and ‘spider genitalia genius‘.  Here’s an example of what she looked at, a lot:

The epigynum of a wolf spider species, (part of) the topic of Katie's research.

The epigynum of a wolf spider species, (part of) the topic of Katie’s research.

In sum, I am thrilled to see Sarah and Katie finish up their work, although their success also comes with a touch of sadness, as I will miss their daily presence in the laboratory.  Stay tuned… we shall soon report all the details from their research.

Assessing five decades of change in a high Arctic parasitoid community

By Christopher Buddle

As my colleague Terry Wheeler mentioned on his blog, our Northern Biodiversity Program team is thrilled to see post-doc Laura Timms‘s paper about Arctic parasitoid wasps published in Ecography!  Our team worked on Ellesmere Island, Nunavut, in 2010, and compared parasitoid wasps to historical collections from the same site that were made in 1961-65, 1980-82, and 1989-92. Parasitoid wasps are at the top of the insect food chain: they lay eggs inside or on top of other arthropods and the wasp larvae emerge after consuming their hosts – a gruesome but very common lifestyle for many types of wasps.  Species at higher trophic levels, such as these parasitoid wasps, are often the first to respond to new environmental pressures, including the climate change that is occurring rapidly in Arctic systems.

Some members of the Northern Biodiversity Program working in the Yukon in 2012. (l-r, Chris Buddle, Laura Timms, Crystal Ernst and Katie Sim)

Some members of the Northern Biodiversity Program working in the Yukon in 2012. (l-r, Chris Buddle, Laura Timms, Crystal Ernst and Katie Sim)

Laura identified a LOT of wasps, recorded the type of host attacked (e.g. plant-feeding hosts versus hosts that are predators), and the body size of two species of wasps that were commonly collected in all time periods.  We found no clear pattern of change in most aspects of the parasitoid wasp community on Ellesmere Island over past 50 years, even though temperature and precipitation have increased significantly during the same period. However, there were some signs that parasitoids of plant-feeding insects may be more affected more than other groups: one common parasitoid species that was abundant in 1960s hasn’t been collected since then, and the community in the 2010 study contained fewer parasitoids of plant-feeding insects than previous studies.

Laura takes it as a good sign that no major changes in the ecology of the high Arctic parasitoid community have been observed, but isn’t taking it for granted that the community will remain unaffected for long.  At 82°N, Ellesmere Island is relatively isolated, but other research has found that parasitoid communities further south are changing dramatically (Fernandez-Triana et al 2011).

Laura has the following comment about our work: “We hope that our findings will be used as baseline data for ongoing monitoring on Ellesmere Island”, said Timms.  “We know so little about these high Arctic insect communities, we should learn as much as possible about them while they are still intact.

References

Timms, L., Bennett, A., Buddle, C., & Wheeler, T. (2013). Assessing five decades of change in a high Arctic parasitoid community Ecography DOI: 10.1111/j.1600-0587.2012.00278.x

Fernandez-Triana, J., Smith, M., Boudreault, C., Goulet, H., Hebert, P., Smith, A., & Roughley, R. (2011). A Poorly Known High-Latitude Parasitoid Wasp Community: Unexpected Diversity and Dramatic Changes through Time PLoS ONE, 6 (8) DOI:10.1371/journal.pone.0023719

Help Build an Arctic Food Web

Posted on behalf of Dr. Chris Buddle (the original post can be found here, at the Arthropod Ecology blog)
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A couple of weeks ago I was fortunate to be able to attend a workshop about monitoring terrestrial arthropod biodiversity in the Arctic. In advance of that workshop, I offered to prepare a draft of a food-web that was ‘Arthropod-centric’.  There are many ways to build a food-web, and my first draft was focused on who eats whom.  In other words, an arrow depicting interactions would indicate predation (loosely defined).  An alternative would be to focus on energy moving through the system (i.e., the arrow would move ‘up’ from trophic level to trophic level, to indicate a transfer of energy).

Putting this together is a challenging, yet rewarding process.   I consulted with many of my colleagues with expertise in Arctic systems (including the folks involved with our Northern Biodiversity Program), and I am struggling to find the right balance between generality and specificity.  Here’s a portion of the (draft) food-web, showing some of the interactions:

Part of an Arctic Food Web, with an Arthropod Focus

When working on this food web, some interesting generalities are emerging: First, the overall dominance of Diptera (flies).  This is certainly because they do everything (e.g., decomposers, pollinators, blood-feeders) and they are very diverse.   Second,  arthropods are integrators – meaning they connect different processes, and they bridge different systems (aquatic/terrestrial).  Third,  highly valued vertebrates  (and humans!) depend on arthropods (and/or are affected by them).

Does all of this pique your interest?  Want to help? Together with colleagues, I am seeking help as this food-web develops.  Send me an e-mail (chris.buddle@mcgill.ca) or drop a comment on this post and think about some of these questions and provide some feedback if you are so inclined:

….what interactions do you think are important in the Arctic, from an arthropod perspective?

….how can the interactions between vertebrates and invertebrates best be depicted?

….what interactions between humans and arthropods need to be included? (other than biting flies – that one is pretty obvious!)

….what ecological processes should be included in an Arctic food-web? 

There are other Arctic food-webs out there.   The Bear Island food-web is probably the best one that focuses on Arctic arthropods.  If you’ve not seen it, the paper by Ian Hodkinson and Stephen Coulson (2004) is worth a look.   That food-web is more specific than the one I am working on (it should be since it’s focused on a specific location and it can be because a lot of research has occurred there!).   I really like one of the last sentences in their paper: ...the Svalbard high Arctic terrestrial food web is far more complex than has previously been appreciated but further sections remain to be resolved.  Indeed!  I would argue that we need to develop these kind of specific food-webs from other locations in the Arctic, but to get there, we also need a general, broad overview that encapsulates the overall role and importance of Arthropods to the Arctic.  Hence the development of a general food web.

I’ll finish with some thoughts about using this blog as a platform for generating and refining ideas about this food web.  Last year I had a long discussion with my PhD student Crystal Ernst (aka the Bug Geek) about the use of social media in the creative thinking process.   Some parts of the discussion we had showed up in one of her posts about the role of social media in science.  There’s a nice quote in that post that really hits the nail on the head:

Social media is just another kind of “hallway talk…in a really, really, long hallway”. (Crystal attributes part of that quote to another fine blogger, Bug Girl)

Social media can be used effectively as a platform for soliciting feedback and generating ideas about science, including specific projects such as building a food-web diagram.   At this stage, I admit that I’m not ready to put the entire draft food-web in this post – it’s far too incomplete.  However, it is the perfect time to ask for help, and solicit ideas.

….I welcome your feedback.

A biting fly update

Patrick Schaefer, an NBP PhD student working at the University of Toronto, recently published an article entitled, “An update on the biting fly component of the Northern Biodiversity Program” in the winter 2011 Biological Survey of Canada Newsletter.

Here’s a brief excerpt:

Preliminary results from the 2010 season suggest that the northern biting fly fauna is far from homogeneous – even on a relatively limited geographical scale. … Furthermore, there is tantalizing evidence that at least some biting flies may be shifting their distributions northwards in response to a changing climate. If this is true, it could have important implications for the hosts of these bloodsucking species.

You can read the rest of this really excellent overview of the more Dipterish components of the NBP program (and enjoy some wonderful photographs of the field work) by clicking here to be redirected to a pdf of the newsletter.

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Reference:

Schaefer, P. 2011. An update on the biting fly component (Diptera: Simuliidae, Culicidae, and Tabanidae) of the Northern Biodiversity Program. Newsletter of the Biological Survey of Canada, 31(2): 41-49.

 

 

The Arctic Circle

On Tuesday, January 10, Crystal Ernst delivered a talk entitled, “Arctic Arthropod Ecology and the Northern Biodiversity Program”, at the annual general meeting of the Arctic Circle, a group of Arctic researchers and aficionados that meets monthly in Ottawa, Ontario.

The talk provided some background information on the importance of arthropods to biodiversity and in ecological research, and some examples of recent changes in the biodiversity of arthropods in northern Canada were explored. There was a discussion of the history of arthropod collection efforts in the Arctic, including the Northern Insect Survey of the mid-1900s. The presentation finished with an overview of the research being undertaken by the Northern Biodiversity Program and some interesting data coming out of an 8-week study of the beetle fauna in Kugluktuk, Nunavut (part of Crystal’s PhD research).

The 45-minute presentation was very well received by an enthusiastic audience of 50+; many thoughtful questions were asked at the end (and again after the meeting had been formally concluded!). Crystal was grateful for the opportunity to work on her lecturing skills with such a receptive group and has been invited to return with an update at a future meeting!

Autumn Wrap-up!

From Chris Buddle:

Hard to believe that we are already into 2012!  Although there has been a distinct lack of blog entries, this does not indicate a lack of activity – quite the opposite!  After our return from successful field trip in August, we were busy all fall sorting specimens, working on identifications, and gearing up for conference season.

The project had very good representation at national and international conferences this past autumn. M.Sc. student Anna Solecki, post-doc Laura Timms, and Terry Wheeler attended the Entomological Society of America’s annual meeting, held this year in Reno, Nevada.  Congratulations to Anna – she won the President’s Prize in a poster competition in Systematics, Evolution and Biodiversity!

The NBP also had good representation at the Entomological Society of Canada’s annual meeting, held in Halifax, Nova Scotia.  Terry and Laura also attended that meeting, as did Katie Sim, Crystal Ernst, Sarah Loboda, Chris Buddle, and the Toronto crew – Patrick Schaefer, Ruben Cordero, and Doug Currie.   Everyone gave oral talks or posters, and it’s very exciting to see preliminary results from the project.   We are especially proud of Katie, as she won the poster competition – congratulations, Katie!  Here’s a photo of Katie with her poster.  Up next – we continue working on sorting, identifications, and some analyses and manuscripts are also being prepared.  Stay tuned…

Katie Sim with her first-place poster!