Month: May 2012

Help Build an Arctic Food Web

/ Chris Buddle / 5 Comments

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 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.

Reference

D. Hodkinson, I., & J. Coulson, S. (2004). Are high Arctic terrestrial food chains really that simple? - The Bear Island food web revisited Oikos, 106 (2), 427-431 DOI: 10.1111/j.0030-1299.2004.13091.x

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Teaching Tips: Grade-less assignments, postcards and tickets

/ Chris Buddle / 6 Comments

Earlier this week, McGill University had the pleasure of hosting Prof. Graham Scott, from Hull University in the UK. He is passionate about the learning process and he brought his expertise and knowledge to a workshop at Macdonald Campus (made possible by the Macdonald Innovations for Teaching Improvement program). The workshop covered many topics including student managed learning, how to facilitate autonomy in students, how field courses benefit the educational experience for undergraduate students, and various other teaching strategies. Some great teaching tips also emerged from the workshop, and I want to share a few of them here. (Note: a longer post about the value field courses will come sometime in the future!).

Grade-less assignments:

This is a strategy I sometimes use in my own courses. Although all class assignments should have value and link to the Learning Objectives for a course, not all assignments should be graded. Grade-less assignments can allow for alternative approaches to discovering course content and assessing skills, and they can bring out creativity from students. For example, a few years ago I asked groups of students to prepare a “map” of a field-day to a local field site (Mont. St Hilaire). The objective of this exercise was to think about ways to depict multi-variate data (as part of that field trip, students gathered many types of information, including observations about plants and animals, discussions about ecosystems, the geological history of the field site, and more). I did a lecture on ways to think about creative data presentation (using Napoleon’s March as inspiration) and in groups, the students were asked to map their field trip. There was no grade associated with this assignment, yet the groups produced the most amazing projections. I was absolutely stunned and thrilled at the creativity, hard work, skill, and attention to detail. Here’s one example:

The Map Project: one group’s depiction of their field trip to Mont St Hilaire

The students told me that because there was no grade associated with the assignment, they were able to have fun, be creative, and explore alternatives without the risk of doing poorly and/or not meeting the instructor’s expectations. They were also able to use their other personal skills (e.g., artistic abilities, graphic design training) and they welcomed that opportunity. What was the incentive? The groups were asked to present to the rest of the class, so there was motivation to do well in front of peers. The other motivating factor was that the students were presented with a challenge, and the challenge was linked directly to the learning objectives of the course. Finally, the groups themselves motivated each other and found value in the assignment beyond the grade. The bottom line is that under some circumstances, grade-less assignments can be an effective teaching tool, and can bring out the very best in students.

Postcard exercise:

In the workshop earlier this week, Graham Scott assembled us into groups, and each individual in a group was asked to write down, on an index card (i.e., the “postcard”), one thing that we thought would help to improve our teaching ability. We did not include our name on this card. The index cards were then traded around the entire room, so each group ended up with a new set of postcards from other individuals. We were then asked to discuss the content of those cards, and rank them in terms of what we viewed as the best ideas on the cards. Because the content was anonymous, we were able to have an open and frank discussion. Each group then presented their results to the rest of the room. This exercise allowed individuals to put down their ideas honestly, and truthful. What was amazing is that there was an incredible convergence of ideas, and what emerged was ‘clusters’ of ways to improve teaching.

An example ‘postcard’ from our exercise about ways to improve teaching. Student-led learning is key.

This small exercise was a very effective way to promote engagement, discussion, and allowed participants to be open and frank with the comfort of anonymity. I can see this working very well with any kind of course. As an example, I can envision ways to incorporate this exercise into a lecture about Animal Diversity - students could be asked to write down what taxon they think are the most diverse, globally, and then the cards could be shared around. Groups could then be formed and students could group cards into categories (e..g, taxonomic, functional, body size) and this could initiate a discussion about mechanisms behind patterns of global diversity. Best of all, everyone would be involved, and all ideas could be discussed. This is “student led” learning - and will help to reduce the biases that an instructor imposes on content. The postcard exercise is simple, cheap, effective, fun, and something I will use next year.

Ticket to enter:

This was an idea raised by one of the workshop participants, and one that Graham Scott had not heard of before (this shows just how important it is to get together and talk about teaching!). Although this exercise was presented as something to be used in a graduate-level course, I think it could work at almost any level of University, and for almost any type of course. Here, before entering a classroom (or before starting lecture, etc) students must write down a “question” related to the course or relevant content. (Note: I must be honest that where the exercise goes from here is different than what was formalized at the workshop - I am taking some liberties to muse about variations on the theme)

The questions can be used in various ways: 1) they could be read out at the start and the lecture could be guided towards the content related to the questions, 2) students could read their own question and be asked to justify why that question is relevant and applicable to the course, 3) at the end of the class, the instructor and students could discuss the questions and see to what degree they were or were not answered, 4) the questions themselves could form a starting point for discussion at the start of class, on that day, or perhaps during the next time the group meets, 5) the questions could be used to form groups which in turn could facilitate a process or project related to researching the questions, 6) the questions could be used to modify the course and its learning objectives in the future…. And I think there are many other options once the questions are in hand.

It’s a ticket to enter because the class won’t start until the students have asked their question. The benefit to this approach is that it helps engage students in the areas of their own interest as related to the course. It also helps to see whether there is a match (or mismatch) between the instructor and the students, and questions are an insightful and powerful way to do this. Good questions are also something critical to the research process yet we do not often focus on how to ask good questions as a core competency at University. Asking good questions is fundamental to the learning process.

In sum, the workshop was inspiring, informative, and Graham Scott helped us see some wonderful innovative and important ways to rethink and retool approaches to teaching. There are many more tips and ideas to share, so please stay-tuned for more to come in future posts….

What are your top teaching tips? Please share!

Opening an ecological black box: entomopathogenic fungi in the Arctic

/ Chris Buddle / 1 Comment

While visiting Alaska last week, I had the pleasure of meeting Niels M. Schmidt. He is a community ecologist (from Aarhus University, Denmark), who studies Arctic sytems and he is one of the key people behind the Zackenberg Research Station in Greenland. He told me about one of his recently published papers (authored by Nicolai V. Meyling, Niels M. Schmidt, and Jørgen Eilenberg) titled “Occurrence and diversity of fungal entomopathogens in soils of low and high Arctic Greenland” (published in Polar Biology).

An ecological black box: the tundra

By definition (from Wikipedia) entomopathogenic fungi act as parasites of insects - these fungi can kill, or seriously disable insects. I was amazed at this paper because I have never given much thought to fungal entomopathogens in the Arctic (despite knowing their prevalence in other ecosystems). Could these fungi be ecologically important in Arctic? I think Arctic community ecology has been seriously understudied, and we know little about what drives the relative abundance of species. From an arthropod perspective, we know that some birds depend on Arthropods for food (e.g. see Holmes 1966), and that flies are important nuisance pests to large mammals (e.g., Witter et al. 2012), but I would argue that most ecological interactions in the Arctic involving arthropods (and their relative importance) remain a mystery. I could not even speculate on the role of fungal entomopathogens in the Arctic. This is one of those feared ‘black boxes in ecology’: probably there, possibly important, likely complex, but knowledge is seriously lacking.

So along comes this paper: Meyling et al. took soil samples from locations in the high and low Arctic (i.e., including Zackenberg, at about 74.5 degrees N), and they returned the samples to their laboratory in Denmark. In their lab, the authors allowed live insects (using Lepidoptera [Pyralidae)] and Coleoptera [Tenebrionidae]) to be exposed to their samples, and they checked regularly for mortality: “...cadavers were rinsed in water, incubated in moist containers and monitored for the emergence of fungi“. Any fungi that emerged from the (dead) host were identified.

The results: they identified five species of fungal entomopathogens (all in the division Ascomycota). As the authors state in the start of their discussion “This study is the first to document fungal entomopathogens in soils from Greenland at both low and high Arctic sites. Furthermore, the use of in vivo isolation with living insect baits explicitly documented pathogenicity to these insects.”

Could this Arctic Weevil die from a fungal infection?

The black box has been opened: indeed, fungal entomopathogens are in the high and low Arctic of Greenland, and are therefore likely in the high and low Arctic around the globe. These fungi probably play a role in arthropod mortality in these systems, but this remains completely understudied. As the authors point out, given the tight relationship between fungi and temperature, what effect could a changing climate have on these fungal entomopathogens? This is potentially very important, as increased mortality of insects by fungi could trickle all the way up the food web… I think we need to get more mycologists into the Arctic, and we must work to properly articulate high Arctic food webs with all the black boxes opened wide.

References:

Holmes, R. (1966). Feeding Ecology of the Red-Backed Sandpiper (Calidris Alpina) in Arctic Alaska Ecology, 47 (1) DOI: 10.2307/1935742

Meyling, N., Schmidt, N., & Eilenberg, J. (2012). Occurrence and diversity of fungal entomopathogens in soils of low and high Arctic Greenland Polar Biology DOI: 10.1007/s00300-012-1183-6

Witter, L., Johnson, C., Croft, B., Gunn, A., & Gillingham, M. (2012). Behavioural trade-offs in response to external stimuli: time allocation of an Arctic ungulate during varying intensities of harassment by parasitic flies Journal of Animal Ecology, 81 (1), 284-295 DOI: 10.1111/j.1365-2656.2011.01905.x

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Holistic views of ecosystems: linking salmon and butterflies

/ Chris Buddle / 4 Comments

Beautiful Anchorage, Alaska

I’ve spent most of my week in beautiful Anchorage, Alaska. I was attending a workshop that brought together scientists from Northern countries to discuss an Arctic Terrestrial Biodiversity Monitoring Plan. The goal of this ambitious plan is to include all key taxa, include all northern countries, and find ways to standardize methods and harmonize data. There were a half dozen bird experts around the table, numerous experts on Arctic vegetation, a large contingent of mammal experts, and one arthropod expert (me). This is a situation I have been in before, and will be in again in the future - largely because arthropods are not “charismatic” nor do they typically fall into management plans. Regardless, I welcomed the opportunity to discuss ways that Arthropods can and should fit into large-scale, and long-term monitoring plans in the Arctic (there are, by the way, some tremendous arthropod monitoring programs underway - the Zackenberg research station in Greenland, for example, has been collecting arthropods using standardized protocols for almost 20 years)

The workshop was exciting, challenging, motivating, and overall a wonderful opportunity to discuss the interdisciplinary concept of biodiversity monitoring. A great example of an interdisciplinary approach was a presentation we heard about using traditional knowledge to understand the Natural Indicators of the Salmon run in the Yukon River, a river that drains out to the ocean in Alaska. This was organized/facilitated by the Yukon River Drainage Fisheries Association. This presentation highlighted a project where Elders were asked about what helped them understand the Salmon run in the river - a critically important process for people living in this part of Alaska. I was amazed to hear that for some Elders, the appearance and activity of certain species of butterflies (and sometimes biting flies) was one of the indicators that was used to predict when the Salmon would run.

An Arctic Butterfly

Yes, you read correctly: Butterfly activity indicates the Salmon run. The claim that activity of insects relates to the Salmon run is not a direct connection as the insect activity was considered as a “Correlative indicator”. The observation is that when certain insects appeared and were active, so were Salmon, hence the correlation. This does make some biological sense as many of the environmental factors affecting butterflies are probably also important to salmon.

The Yukon River Drainage Association went on help to produce a children’s book titled “When Will the Salmon Come?“. This is a richly illustrated, beautiful book that discusses all the Natural Indicators that Elders use to know when Salmon will appear on the river, and the insect activity is highlighted. A children’s book is a wonderful way to connect with a broad audience.

When will the salmon come? (the book cover)

Being a skeptical scientist, I went and searched the literature for anything ‘published’ on the topic of Salmon and butterflies, and I could not find anything. This does NOT mean it’s not a real and important observation. It means that it is a truly fascinating and curious correlation that was observed by Elders living close to the river, and by people who likely approach nature from a holistic standpoint. I need to do this more; we all need to do this more. Natural systems are interdisciplinary yet we often study them in silos, defined by a specific taxon or system.

In sum, I was most pleased to be the lone entomologist in a large interdisciplinary workshop about biodiversity monitoring in the fragile Arctic - my horizons were certainly broadened. The story of butterflies and salmon made me take a step back and consider how different groups of people can bring different perspectives and all are equally valid. In other words, keep an open mind, and think of this story when you see some butterflies passing by…they could be telling you an important story - you just have to listen.

Rethinking guild classifications for insect herbivores

/ Chris Buddle / Leave a comment

This is the start a (somewhat) regular series of blog posts highlighting some of my favourite research papers in the discipline of Arthropod ecology - I’ll call this category “must-read research papers”. These posts will force me to look critically at some of the great research papers I have read in the past little while, figure out the ‘take home messages’ from these papers, and articulate this message. I also hope these posts can inspire others to think about the best papers within their discipline and to share their opinions and ideas to a broad audience. That is what science communication is all about!

Typical herbivory by a “leaf chewing” insect

For the first in this series, I wanted to highlight a paper by Novotny (and fifteen other co-authors) published in 2010 in the Journal of Animal Ecology. This work is titled “Guild-specific patterns of species richness and host specialization in plant–herbivore food webs from a tropical forest.” This paper was discussed in my Insect Diversity class last autumn (co-taught with Terry Wheeler), and was used as an example of assumptions we make when considering what it means to be a herbivore. From my biassed perspective (working mostly in north-eastern deciduous forests and the Arctic), when I think about herbivores, I automatically classify herbivores into a few pretty obvious categories: leaf chewers, leaf miners, gall-makers, and a suite of ‘piercing-sucking’-type herbivores. My off-the-cuff estimate of the number of herbivore guilds would be much less than a dozen.

Novotny et al.’s paper really shook up my view of what it means to be a herbivore. Using their considerable data and expertise from work in Papua New Guinea, the authors refine plant-herbivore food webs and, quite simply, explode the concept. The authors classified insect herbivores by their main mode of feeding (chewing, sucking), developmental stages (larvae, adult), where they feed (internally, externally), and by the plant part which is fed upon (leaves, flowers, fruits, xylem, phloem, etc). Their system resulted in 72 classifications - which they reduced down to more manageable 24 - still over double what my initial estimate was. Their system certainly includes the classic guilds (e.g., leaf chewers) but also included some wonderfully detailed interactions that are easily overlooked (especially by someone who studies spiders…). For example, fruit chewers, flower chewers, and xylem suckers. As an aside, and for some eye candy, here’s a nice photo of a caterpillar from The Bug Geek (reproduced here, with permission)

A cryptic caterpillar, (c) C. Ernst

The authors then took their new and detailed classification system and completed a food web analysis for their tropical system in Papua New Guinea, focusing on 11 main guilds. Their resulting 11 food-web diagrams are a lovely depiction of multivariate data in 2-dimensions, as they show the frequency with which each host plant is consumed by herbivores, the herbivore abundance and the frequency of each interaction - and they present this for 9 standardized plant species, for each of the 11 guilds. Their research depicts “6818 feeding links between 224 plant species and 1490 herbivore species drawn from 11 distinct feeding guilds”. WOW! They also show that 251 species of herbivores are associated with each tree species within their study system. There are clearly a lot of different ways for herbivores to make a living.

This paper represents a major undertaking, and it is a bit sobering to see the results and see that despite the efforts, relatively few ‘generalities’ exist - that is to say, there are examples of extreme host specificity, extreme generalist feeding, and everything in between. Here’s a quote from that paper to illustrate that point:

“We documented a wide range of host specificity patterns among herbivorous guilds: host specificity measures spanned almost the full range of theoretically possible values from extreme trophic generalization to monophagy. These results demonstrate the importance of taxonomically and ecologically comprehensive studies, as no single guild can be designated as ecologically representative of all herbivores.”

Mealybugs: another type of herbivore. (c) C. Ernst, reproduced with permission

What’s the take-home message?

For me, this is a strong paper that depicts effectively the complexity of plant-herbivore food-webs and illustrates (once again!) that diversity in tropical forests is stunning. More than that, the work shows this diversity from a functional, food-web perspective, and illustrates how guilds behave differently. From a more practical perspective, this paper is forcing me to rethink how I view herbivores - i.e., they are more than leaf-chewing caterpillars and aphids. They are also root-feeders, fruit chewers, flower chewers, and specialized xylem suckers. Novotny et al. suggest researchers use their 24 guild system for classifying insect herbivores, and I agree - their classification system is still manageable, yet much more comprehensive than what many researchers use.

If the topic of food-webs, plant-insect interactions, and the biodiversity & ecology of tropical forests interests you, this is a must-read paper.

Reference:

Novotny, V., Miller, S., Baje, L., Balagawi, S., Basset, Y., Cizek, L., Craft, K., Dem, F., Drew, R., Hulcr, J., Leps, J., Lewis, O., Pokon, R., Stewart, A., Allan Samuelson, G., & Weiblen, G. (2010). Guild-specific patterns of species richness and host specialization in plant-herbivore food webs from a tropical forest Journal of Animal Ecology, 79 (6), 1193-1203 DOI: 10.1111/j.1365-2656.2010.01728.x

Professors take the summer off (another myth of Academia….)

/ Chris Buddle / 1 Comment

The academic term is over, and so are my teaching duties (until September). This is the time of year that I sometimes get asked how I am going to spend my summer off from work. Many people think that Professors teach University classes and then sit back and relax for four months every summer - Oh, we may wander in to work now and then, do some ‘critical thinking’, muse poetically about society and our place in it, but by in large, the summer is for leisure time, long lunches, vacation, and recovery after that tough eight months of teaching.

WRONG!

For a Professor at a University with a research focus in addition to teaching duties, the summer is for making significant progress on research. For a field biologist, such as myself, summer is often the busiest time of year. Studying animals outside (in Northern countries) means that we must cram a lot of work into four short months! Quite often we also work on grant applications (many of these are due in the early Autumn), and without grants, our research programs will fail. Yes, the summer offers some flexibility, but it certainly isn’t all leisure - a lot of work must get done and the expectations are high.

Dorothy showing off some excellent “single rope technique” for accessing maple tree canopies

In my laboratory this summer, Dorothy Maguire (who did pass her comprehensive examination successfully - congratulations, Dorothy) will be doing her second summer of field work on her PhD project about the effects of forest fragmentation on hebivory (by insects) in the Montérégie. This project is done in collaboration with Dr. Elena Bennett’s research team (and Elena is Dorothy’s co-supervisor). This work is very exciting and novel, in part because Dorothy is putting this work in the context of “ecosystem services” -i.e., the various services that humans get from ecosystems. Insects feed on trees, and trees are valuable to humans, so the linkages between insect herbivores and ecosystem services are important to study, especially in the context of fragmented forests of SW Quebec.

We also have a field team heading up to the Yukon Territory to finish some field collections in the context of the Northern Biodiversity Program. Katie, Crystal, and Laura will be collecting spiders, beetles, parasitoids (& more) along the Dempster Highway (one of the most beautiful places on the planet).

The Dempster Highway, Yukon.

To help us prepare for the summer, we must first clean up our messy lab. As is tradition in the Arthropod Ecology Laboratory, spring cleaning happened this past week. We put on a brave face, tackle all the dark corners of the laboratory, throw out unlabelled material, clean the desks and discover quite a number of surprises. A couple of lovely finds this year included an unlabeled 10 lb bag of soil at the bottom of a fridge (yikes!), and a colony of Collembola (springtails) from 2003!! (there was no evidence of life within that jar, yikes again!):

Crystal and Raphael laughing about the ‘unknown’ bag of soil.

Springtime is therefore an exciting time in the lab, and as an Academic at McGill, it’s an important period of transition from a teaching focus to a research focus. I certainly do take my official vacation time in the summer, but in addition to that time, the summer months are busy and (hopefully) productive. Remarkably, I can also find time to use a microscope again - this is a rare event, as this post describes. Want proof? Here you go:

Chris Buddle actually doing laboratory work. Wonders never cease.

Is the Emerald Ash Borer in Montreal a real threat?

/ Chris Buddle / 2 Comments

You may have heard about the latest insect pest to invade Quebec - it’s a small beetle, known as the Emerald Ash Borer (Agrilus planipennis), that feeds on ash trees. The species has been detected in about 15 trees on the Island of Montreal, and it has made headlines in the local French and English press. In this post I wanted to provide some perspectives and context to this invasion, and ask whether this is a real threat, or mass hysteria.

The short answer: yes, the Emerald Ash Borer is a real threat to Ash trees, and it is VERY important for people to watch for this species.

Emerald Ash Borer, Photo from Forestry Images, Copyright: Debbie Miller, USDA Forest Service, Bugwood.org

The long answer: There is a lot of information on the Internet about this species, and I will not repeat it all here. Instead, I will try to stick to the main facts, and highlight some of the recent research that has been published about the species. I do recommend people spend time on the Canadian Food Inspection Agency’s (CFIA) website devoted to the species.

History of Introduction:

The Emerald Ash Borer is native to parts of Asia, and for that reason, it is considered as an Introduced species (or alien, or exotic) in North America. Many people use the word ‘invasive’ to describe the species -but this term should be paired with the word Introduced, as this species is invasive in the sense of spreading fairly quickly to new regions and introduced in the sense of not being indigenous to North America.

The Emerald Ash Borer probably arrived in North America in the 1990s (or even 1980s) but was not officially detected until the early 2000s, and that detection was in Michigan, and then almost simultaneously in Windsor, Ontario. It is believed that the species was introduced by accident through wood packing material - this is a very common route of introduction for a host of species, notably wood-boring beetles. Since the first detection, the species has been found in many regions of Ontario, Gatineau (Quebec), and it has been in Montreal for over a year (the first detection in Quebec was in Carignan, south of Montreal). It is likely that the introduction to Montreal was a separate (but related) introduction from elsewhere in Ontario or the USA - e.g., via movement of wood debris, firewood. It is unlikely that the Emerald Ash Borer came to Montreal through its own dispersal - if so, it certainly would have been detected in may regions between Montreal and SW Ontario.

Appearance, Habits, & Hosts:

The adult form of the beetle is quite attractive - the adults are rather small (about 8-14 mm in length - this is about the length of my own pinky finger-nail), metallic green, and its head is somewhat flattened and shield-like. It is fairly distinctive and I don’t think it is easily confused with any native species. It is in the family Buprestidae, which have the common name of “metallic wood boring beetles” - many Buprestids share a similar body shape (or habitus) to the Emerald Ash Borer. The larvae of the species is ‘grub-like’ in some ways (see below), and the larvae are the most active feeding stage -it’s at this stage that they feed underneath the bark of Ash trees, and can slowly kill the tree through their feeding activities (they essentially girdle the tree). It may take several years for tree mortality to occur.

The different life stages of the Emerald Ash Borer. Photo from Forestry Images, copyright, Debbie Miller, USDA Forest Service, Bugwood.org

The adults lay eggs on the host tree, and the larvae burrow into the bark, make “feeding galleries” (serpentine shaped), moult, grow, and eventually pupate and exit the tree through a ‘d-shaped’ exit hole - after pupation, the adults will eat leaves, fly around, mate, and the process starts again. Adults usually appear from mid-May until the early summer. Although not ‘vigorous’ flyers, the Emerald Ash borer can disperse many kilometres.

Galleries made by the larvae of the Emerald Ash Borer, photo from Forestry Images, (c) Michigan Department of Agriculture, Bugwood.org

The hosts of the Emerald Ash borer, as recorded in North America so far, are trees within the genus Fraxinus - i.e., ash trees. These are extremely common trees as both an ‘urban’ tree on streets and in parks within the city, but also occur naturally in local forests (e.g., the Morgan Arboretum). There is sometimes confusion about the “Mountain Ash” trees - this is not a ‘true’ ash, so it is not a host for the Emerald Ash borer.

Many species of wood-feeding beetles generally prefer to feed on, and complete their life cycles, on recently dead, weakened, and/or decaying trees. However, the Emerald Ash borer is different: it will feed upon and lay its eggs in healthy trees as well as weakened/damaged trees, and this is certainly one of the reasons why the species is of significant concern.

(Local) Management of the Emerald Ash Borer:

The city of Montreal (together with the CFIA) is taking the threat for the Emerald Ash Borer very seriously, including monitoring, targeted use of a bio-pesticide, and in providing information to the public, especially about movement and disposal of branches / firewood / yard scraps, etc. In some areas, a Ash-tree removal program has been used to stop the spread, with mixed results.

Education is extremely important with this pest: early detection is important to stop the spread, but so is limiting movement of any wood. Ash trees are not as recognizable as other species, and for that reason, when you have wood debris around, the city is asking you to call 311 for proper wood disposal. For further details, you can call you local municipally or click here for details. Again, the ability to detect the species will provide the best chances for limiting further spread and further damage. You ALL are invited to become an entomologist! Study the photographs of the Emerald Ash Borer and develop a search image - if you see the species in your yard, call 311, or your local municipal office and have the experts determine the best course of action.

Recent Research on the Emerald Ash Borer:

This has been a rather dramatic increase in the number of papers that have been published on Agrilus planipennis. Using that species name as a search term, you can see the increase in scientific interest based on the following graph pulled from Web of Science:

Number of publications, by year, on the Emerald Ash Borer, from Web of Science

I am pleased to report that a biological control program has been started in the USA - parasitic wasps that use the Emerald Ash Borer as a host have been released, and are showing some potential at helping to control the pest - some good details are available here. Duan et al, have just published a paper reporting the incidence of parasitism for many hymenopteran parasitoids, and have also shown that woodpeckers account for a lot of mortality of the Emerald Ash Borer larvae, and ‘undetermined factors’ (includes diseases, potential host plant resistance) can also cause significant mortality (by the way, increased woodpecker activity on Ash trees could be a sign of an infestation).

Sobek-Swant et al. published a paper in January 2012 - they were curious about whether the species might be limited by cold winter temperatures - this is an important mechanism to test, especially at our (relatively) northern latitudes. However, under laboratory conditions, the authors found that the Emerald Ash Borer will unlikely be limited by ‘climatic’ factors, and instead, the presence of its host trees will be the most important factor. In other words: the species may eventually be found throughout the range of its host.

About a year ago, Ryall et al. published a very important paper on the Emerald Ash Borer. In this work, the researchers point out that the species is difficult to detect at low population levels, mainly because it make take several years before really noticeable mortality of Ash trees occurs. In other words, the larvae are ‘cryptic’ and may be doing damage before we can fully detect either the species or the damage to the tree. Detection methods can be destructive (e.g., stripping bark) so the authors propose using a relatively non-destructive branch-clipping technique to do monitoring for the species. This is something recommended to cities so that they can do broader areas of monitoring without destructive sampling. This can help significantly in pinpointing where the species is, and can help inform the best management strategy.

In 2011, Mercader et al. also published a paper of practical importance. In this work, the researchers simulated three management options for the Emerald Ash Borer to see which was most effective. Their three scenarios were: (i) removing the host tree (ii) girdling (killing) ash trees to attract ovipositing female beetles and destroying the trees before the larvae develop (this is a type of ‘trap tree’, i.e., you attract the species to a location and then trap and kill them) and (iii) applying a systemic insecticide. Their results suggest that the best way to stop or reduce the spread of Emerald Ash Borer is through the use of a systematic insecticide.

Outlook:

I am pessimistic that we will see success in eradicating the species from Montreal and surrounding areas, but slowing the spread is important and could allow for researchers to develop and fine tune other management options. Again, please educate yourself and learn what the Emerald Ash Borer looks like, and please do not move around wood and branches from your property to another location.

Emerald Ash Borer, on pin. Image from Forestry Images, (c) Pest and Diseases Image Library, Bugwood.org

References:

Duan, J., Bauer, L., Abell, K., & Driesche, R. (2011). Population responses of hymenopteran parasitoids to the emerald ash borer (Coleoptera: Buprestidae) in recently invaded areas in north central United States BioControl, 57 (2), 199-209 DOI: 10.1007/s10526-011-9408-0

Sobek-Swant, S., Crosthwaite, J., Lyons, D., & Sinclair, B. (2011). Could phenotypic plasticity limit an invasive species? Incomplete reversibility of mid-winter deacclimation in emerald ash borer Biological Invasions, 14 (1), 115-125 DOI: 10.1007/s10530-011-9988-8

Ryall, K., Fidgen, J., & Turgeon, J. (2011). Detectability of the Emerald Ash Borer (Coleoptera: Buprestidae) in Asymptomatic Urban Trees by using Branch Samples Environmental Entomology, 40 (3), 679-688 DOI: 10.1603/EN10310

Mercader, R., Siegert, N., Liebhold, A., & McCullough, D. (2011). Simulating the effectiveness of three potential management options to slow the spread of emerald ash borer populations in localized outlier sites
Canadian Journal of Forest Research, 41 (2), 254-264 DOI: 10.1139/X10-201

(thanks to Chris MacQuarrie for helping me with this post)