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Canadian Entomology Research Roundup: September 2015 – January 2016

(version française)

As part of a continuing series of Canadian Entomology Research Roundups, here’s what some Canadian entomology grad students have been up to lately:

From the authors:

Finn Hamilton (University of Victoria)

It is now well known that the majority of insects host symbiotic bacteria that have profound consequences for host biology. In some cases, these symbioses can protect hosts against virulent parasites and pathogens, although in most cases it remains unclear how symbionts achieve this defense. In this paper, we show that a strain of the bacterium Spiroplasma that protects its Drosophila host against a virulent nematode parasite encodes a protein toxin. This toxin appears to attack the nematode host during Spiroplasma-mediated defense, representing one of the clearest demonstrations to date of mechanisms underpinning insect defensive symbiosis. Article link

Drosophila

This is a Drosophila falleni fly infected by the nematode, Howardula aoronymphium, which Spiroplasma protects against. Photo credit: Finn Hamilton.

Lucas Roscoe (University of Toronto)

The Emerald Ash Borer (Agrilus planipennis Fairmaire, EAB) is a buprestid pest of ash trees in North America. As part of the development of long-term management plans for EAB, several projects detailing the biology and ecology of poorly-known, yet indigenous parasitoids associated with EAB were initiated. One project concerned the mating sequences of the chalcidid parasitoid, Phasgonophora sulcata Westwood. Many insects undertake repeatable actions prior to mating. These are commonly mediated by pheromones. The results of this research were the description of the mating sequence of P. sulcata, and evidence of female-produced pheromones that initiate these actions. Article link

sulcata

Phasgonophora sulcata, an important parasitoid of the emerald ash borer. Photo credit: Lucas Roscoe.

Marla Schwarzfeld (University of Alberta)

The parasitic wasp genus Ophion (Hymenoptera: Ichneumonidae) is almost entirely unknown in the Nearctic region, with the vast majority of species undescribed. In this study, we published the first molecular phylogeny of the genus, based on COI, ITS2, and 28S gene regions. While focusing on Nearctic specimens, we also included representatives of most known species from the western Palearctic region and several sequences from other geographical regions. We delimited 13 species groups, most recognized for the first time in this study. This phylogeny will provide an essential framework that will hopefully inspire taxonomists to divide and conquer (and describe!) new species in this morphologically challenging genus. Article link

Ophion

A parasitoid wasp in the genus Ophion. Photo credit: Andrea Jackson

Seung-Il Lee (University of Alberta)

Seung-Il Lee and his colleagues (University of Alberta) found that large retention patches (> 3.33 ha) minimize negative edge effects on saproxylic beetle assemblages in boreal white spruce stands. Article link    Blog post

beetle

A saproxylic beetle, Peltis fraterna. Photo credit: Seung-Il Lee.

Paul Abram (Université de Montréal)

The relationship between insect body size and life history traits (e.g. longevity, fecundity) has been extensively studied, but the additional effect of body size on behavioural traits is less well known. Using the egg parasitoid Telenomus podisi Ashmead (Hymenoptera: Platygastridae) and three of its stink bug host species as a model system, we showed that body size differences were associated with a change in a suite of not only life history parameters (longevity, egg load, egg size), but also several behavioural traits (walking speed, oviposition rate, host marking speed). Our results highlight how the entire phenotype (behaviour and life history) has to be considered when assessing associations between body size and fitness. Article link

Telenomus

The parasitoid Telenomus podisi parasitizing eggs of the stink bug Podisus maculiventris. Photo credit: Leslie Abram.

Delyle Polet (University of Alberta)

Insect wings often have directional roughness elements- like hairs and scales- that shed water droplets along the grain, but why are these elements not always pointing in the same direction? We proposed that three strategies are at play. Droplets should be (1) shed away from the body, (2) shed as quickly as possible and (3) forced out of “valleys” formed between wing veins. A mathematical model combining these three strategies fits the orientation of hairs on a March fly wing (Penthetria heteroptera) quite well, and could readily be applied to other species or bioinspired materials. Article link

Winghairs

Hairs on a March fly (Penthetria heteroptera) wing. Photo credit: Delyle Polet.

In-brief research summaries

Taxonomy, Systematics, and Morphology

Thomas Onuferko from the Packer Lab at York University and colleagues carried out an extensive survey of bee species in Niagara Region, Ontario. Onuferko et al. collected over 50 000 bees and discovered 30 species previously not recorded in the area. Article link

Christine Barrie and colleague report the Chloropidae flies associated with common reed (Phragmites) in Canada. Article link

 Behaviour and Ecology 

Blake Anderson (McMaster University) and colleagues investigates the decoupling hypothesis of social behaviour and activity in larval and adult fruit flies. Article link

Susan Anthony from the Sinclair Lab at Western University, along with Chris Buddle (McGill University), determined the Beringian pseudoscorpion can tolerate of both cold temperatures and immersion. Article link

A study by Fanny Maure (Université de Montréal) shows that the nutritional status of a host, the spotted lady beetle (Coleomegilla maculata), influences host fate and parasitoid fitness. Article link

Is connectivity the key? From the Buddle and Bennett Labs at McGill University and the James Lab at (Université de Montréal), Dorothy Maguire (McGill University) and colleagues use landscape connectivity and insect herbivory to propose a framework that examines that tradeoffs associated with ecosystem services. Article link

 Alvaro Fuentealba (Université Laval) and colleague discovered that different host tree species show varying natural resistance to spruce budworm. Article link

Insect and Pest Management

Rachel Rix (Dalhousie University) et al. observed that mild insecticide stress can increase reproduction and help aphids better cope with subsequent stress. Article link

Lindsey Goudis (University of Guelph) and others found that the best way to control western bean cutworm is to apply lambda-cyhalothrin and chlorantraniliprole 4 to 18 day after 50 % egg hatch. Article link

Matthew Nunn (Acadia University) and colleague document the diversity and densities of important pest species of wild blueberries in Nova Scotia. Article link

Physiology and Genetics

Does heterozygosity improve symmetry in the Chilean bee, Xeromelissa rozeni? Margarita Miklasevskaja (York University) and colleague tested this hypothesis in their recent paper. Article link

Xeromelissa

A Chilean male Xeromelissa rozeni. Photo credit: Margarita Miklasevskaja.

Recent University of Alberta graduate Jasmine Janes and others explored the mating systems and fine-scale spatial genetic structure for effective management of mountain pine beetle. Article link

Also from the Sperling Lab at the University of Alberta, Julian Dupuis and Felix Sperling examined the complex interaction of hybridization and speciation. They characterized potential hybridization in a species group of swallowtail butterflies. Article link

Marina Defferrari (University of Toronto) and colleagues identified new insulin-like peptides in Rhodnius prolixus and that these peptides are involved in the metabolic homeostasis of lipids and carbohydrates. Article link

Techniques

Crystal Ernst (McGill University) and colleague sampled beetles and spiders in different northern habitats. They found that the diversity of beetles and spiders are affected by habitat and trap type. Article link

 


We are continuing to help publicize graduate student publications to the wider entomological community through our Research Roundup. If you published an article recently and would like it featured, e-mail us at entsoccan.students@gmail.com. You can also send us photos and short descriptions of your research, to appear in a later edition of the research roundup.

For regular updates on new Canadian entomological research, you can join the ESC Students Facebook page or follow us on Twitter @esc_students.

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Rassemblement de la recherche entomologique canadienne: Septembre 2015 – Janvier 2016

(English version here)

Cet article fait partie d’une série continue de rassemblement de la recherche entomologique canadienne (Canadian Entomology Research Roundups). Voici ce que les étudiants de cycle supérieur canadiens ont fait récemment:

De la part des auteurs:

Finn Hamilton (University of Victoria)

C’est bien connu que la majorité des insectes sont hôtes à des bactéries symbiotiques qui ont de profondes conséquences sur la biologie de l’hôte. Dans certains cas, ces symbioses peuvent protéger l’hôte contre de virulents parasites et pathogens, même si dans la plupart des cas planent encore un mystère sur la façon dont les symbionts réussissent à atteindre cette défense. Dans cet article, nous avons démontré qu’une souche de la bactérie Spiroplasma qui protège son hôte drosophile contre un nématode parasitaire virulent encode une toxine sous forme de protéine. Cette toxine semble attaquer l’hôte du nématode durant une défense induite par Spiroplasma. Ceci représente, à ce jour, une des démonstrations les plus claires des mécanismes sous-jacents de la symbiose promouvant la défense des insectes. Lien vers l’article

Drosophila

Voici une mouche Drosophila falleni infecté par le nematode, Howardula aoronymphium, dont Spiroplasma  la protège. Crédit phot: Finn Hamilton.

Lucas Roscoe (University of Toronto)

L’agrile du frêne (Agrilus planipennis Fairmaire) est un buprestide ravageur s’attaquant aux frênes d’Amérique du Nord. Dans l’optique du développement de plans de gestion à long-terme de l’agrile du frêne, plusieurs projets détaillant la biologie et l’écologie de parasitoïdes indigènes peu étudiés auparavant ont été amorcés. Un des projets s’intéresse à la séquence de reproduction d’un parasitoïde, Phasgonophora sulcata Westwood. Plusieurs insectes entreprennent des actions répétées avant la reproduction qui sont souvent induites par des phéromones. Les résultats de cette étude sont la description de la séquence de reproduction de P. sulcata et la preuve que les phéromones produites par les femelles sont à la base de ses actions. Liens vers l’article

sulcata

Phasgonophora sulcata, un parasitoïde important de l’agrile du frêne. Crédit photo: Lucas Roscoe.

Marla Schwarzfeld (University of Alberta)

Les guêpes parasitiques du genre Ophion (Hymenoptera: Ichneumonidae) sont presqu’entièrement inconnu dans la région Néarctique, où la majorité des espèces ne sont pas décrites. Dans cette étude, nous publions la première phylogénie moléculaire de ce genre, basé sur les régions COI, ITS2, and 28S. Bien que nous mettions l’accent sur les spécimens Néarctique, nous avons aussi inclus des représentants des espèces les plus connus de de l’ouest de la région Paléarctique et plusieurs séquences d’autre régions géographiques. Nous avons délimités 13 groupes d’espèces, la plupart étant reconnu pour la première fois dans cette étude. Cette phylogénie nous fournit un cadre essentiel qui pourra, nous espérons, inspirer les taxonomistes à divisier et conquérir (et décrire!) de nouvelles espèces dans ce genre qui présente de grands défis morphologiques. Liens vers l’article

Ophion

A parasitoid wasp in the genus Ophion. Photo credit: Andrea Jackson

Seung-Il Lee (University of Alberta)

Seung-Il Lee et ses collègues (University of Alberta) ont trouvé que de larges territoires de rétention (> 3.33 ha) minimisent “l’effet de bordure” négatif sur les coléoptères saproxyliques dans les peuplements boréals d’épinette blanche. Liens vers l’article  Billet de blogue (EN)

beetle

Un coléoptère saproxylique, Peltis fraterna. Crédit photo: Seung-Il Lee.

Paul Abram (Université de Montréal)

La relation entre la taille des insectes et certains traits distinctifs (tel que la longévité, la fécondité, …) a été largement étudié, mais l’effet additionnel de la taille sur les traits comportementales sont moins bien connus. En utilisant le parasitoïde d’oeuf  Telenomus podisi Ashmead (Hymenoptera: Platygastridae) et trois de ses hôtes punaises comme système modèle, nous avons démontrés que la différence de taille était associé a un changement dans la plusieurs traits distinctifs (longévité, masse d’oeufs, taille des oeufs), mais aussi de certains traits comportementales (vitesse de marche, taux d’oviposition, taux de marquage des oeufs). Nos résultats mettent en relief comment la phénotype complet (comportement et traits distinctifs) doivent être considéré quand nous évaluons l’association entre la taille et la condition physique. Liens vers l’article

Telenomus

Le parasitoïde Telenomus podisi parasitisant les oeufs de la punaise Podisus maculiventris. Crédit photo: Leslie Abram.

Delyle Polet (University of Alberta)

Les ailes de insectes ont souvent des éléments directionnels rugueux – comme des poils et des écailles- qui perdent des gouttes d’eau dans le sens des éléments, mais pourquoi ces éléments ne pointent pas toujours dans la même direction? Nous avons proposé que trois stratégies sont en jeu. Les gouttes pourrait être (1) évacuer loin du corps, (2) être perdues aussi vite que possible et (3) évacuer de “vallées” formés entre les veines des ailes. Un modèle mathématique combinant trois de ces stratégies concorde avec l’orientation des poils sur un taon (Penthetria heteroptera) assez bien et pourrait être appliqué à d’autres espèces ou à des matériaux inspirés par la biologie. Liens vers l’article

Winghairs

Poils sur l’aile d’un taon (Penthetria heteroptera). Crédit photo: Delyle Polet.

Résumés bref de recherche

Taxonomie, Systématique, and Morphologie

Thomas Onuferko du laboratoire Packer à York University et ses collègues ont réalisé un vaste étude sur les espèces d’abeilles dans la région de Niagara, Ontario. Onuferko et al. ont collecté plus de 50 000 abeilles et ont découvert 30 espèces qui n’avait pas été rapporté dans la région. Liens vers l’article

Christine Barrie et ses collègues ont signalé que des mouches de la famille Chloropidae sont associés aux phragmites au Canada. Lien vers l’article

Comportment et écologie

Blake Anderson (McMaster University) et ses collègues ont étudié l’hypothèse du découplage du comportement social et de l’activité dans les mouches larvaires et adultes. Lien vers l’article

Susan Anthony du laboratoire Sinclair à Western University, ainsi que Chris Buddle (McGill University), ont déterminé que le pseudoscorpion de Béringie peut tolérer tant les basses températures et l’immersion. Lien vers l’article

Une étude par Fanny Maure (Université de Montréal) démontre que le status nutritionnel d’un hôte, la coccinelle maculée (Coleomegilla maculata), influence le destin de l’hôte et condition physique du parasitoïde. Lien vers l’article

Est-ce que la connectivité est la clé? Des laboratoires Buddles et Bennet à l’Université McGill et du laboratoire James à l’Université de Montréal, Dorothy Maguire (Université McGill) et ses collègues ont utilisé la connectivité du paysage et les insectes herbivores pour proposer un cadre pour examiner les compromis associés aux services ecosystèmiques. Lien vers l’article

 Alvaro Fuentealba (Université Laval) et ses collègues ont découvert que différentes espèces d’arbres hôtes montrent des variations à la résistance naturelle à la tordeuse du bourgeon de l’épinette. Lien vers l’article

Gestion des insectes ravageurs

Rachel Rix (Dalhousie University) et al. ont observé qu’un stress modéré induit par l’insecticide pour augmenter la reproduction et aider les pucerons a mieux se débrouiller avec le stress subséquent. Lien vers l’article

Lindsey Goudis (University of Guelph) et ses collègues ont découvert que la meilleure façon de contrôler Striacosta albicota (Smith) est d’appliquer de la lamba-cyhalothrine de la chlorantraniprole 4 à 18 jours après l’éclosion de 50% des oeufs. Lien vers l’article

Matthew Nunn (Acadia University) et ses collègues ont documenté la diversité et densité d’importantes espèces ravageuses des bleuets sauvages en Nouvelle-Écosse. Lien vers l’article

Physiologie et génétique

Est-ce que l’heterozygositie améliore la symétrie de Xeromelissa rozeni?  Margarita Miklasevskaja (York University) et ses collègues ont testé cette hypothèse dans leur plus récent article. Lien vers l’article

Xeromelissa

Un male Xeromelissa rozeni. Crédit photo: Margarita Miklasevskaja.

Jasmine Janes, récemment graduée de University of Alberta, et d’autres ont exploré les systèmes de reproduction et de structure génétique à petite échelle pour la gestion efficace du Dendroctone du pin ponderosa. Lien vers l’article

Du laboratoire Sperling à University of Alberta, Julian Dupuis et Felix Sperling ont examiné l’interaction complexe de l’hybridation et de la spéciation. Ils ont caractérisé le potentiel d’hybridation dans un groupe de Papilonidae. Lien vers l’article

Marina Defferrari (University of Toronto) et ses collègues ont identifié un nouveau peptide similair à l’insuline dans Rhodnius prolixus. Ses peptides sont impliqués dans l’homéostasie métaboliques des lipides et carbohydrates. Lien vers l’article

Techniques

Crystal Ernst (McGill University) et ses collègues ont collecté des coléoptères et des araignées dans différents habitats du Nord. Ils ont trouvé que la diversité des coléoptères et des araignées par habitat et type de trappes. Lien vers l’article


Nous continuous à aider à divulguer les publications des étudiants de cycle supérieur à la plus vaste communauté entomologique grâce aux rassemblement de recherche. Si vous avez publié un article récemment et souhaitez le divulguer, envoyez-nous un email à entsoccan.students@gmail.com.  Vous pouvez aussi nous envoyer des photos et une courte description de votre recherche dans le but apparaître dans notre prochain rassemblement de recherche.

Pour des mises à jour régulières sur la nouvelle recherche entomologique canadienne, vous pouvez joindre la page Facebook de ESC Students ou nous suivre sur Twitter @esc_students (EN) ou @esc_students_fr (FR).

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Canadian Entomology Research Roundup: June 2015 – September 2015

As part of a continuing series of Canadian Entomology Research Roundups, here’s what some Canadian entomology grad students have been up to lately:

Ecology and Evolution

Rasoul Bahreini (University of Manitoba) found that honeybee breeding can improve tolerance to Varroa mites which can help minimize colony losses in the winter and improve overwintering performance (Article link). Rasoul also found that reducing ventilation may be an effective way to manage Varroa mite infestation in overwintering honeybee colonies (Article link), and that Nosema infection restrained Varroa removal success in bees (Article link).

A setup to study the effects of Nosema on Varroa mite removal in honeybees (Photo: Rasoul Bahreini)

A setup to study the effects of Nosema on Varroa mite removal in honeybees (Photo: Rasoul Bahreini)

A novel method based on agar-polydimethylsiloxane devices to quantitatively investigate oviposition behaviour in Drosophila melanogaster was described by Jacob Leung and colleagues (York University) (Article link).

Paul Abram (Université de Montréal) and his colleagues found that a predatory stink bug has control of egg colouration, depending on whether it is laying on the top or underside of leaves.  The pigment protects developing embryos against UV radiation (Article link). See also a related post on the ESC blog, an article in the New York Times, and a dispatch article in Current Biology.

A spined soldier bug female, with the range of egg colours she is capable of laying (Photo: Leslie Abram/Paul Abram/Eric Guerra)

A spined soldier bug (Podisus maculiventris) female, with the range of egg colours she is capable of laying (Photo: Leslie Abram/Paul Abram/Eric Guerra)

Philippe Boucher and colleagues (Université du Québec à Rimouski/Chicoutimi) found that ant colonization of dead wood plays a role in nitrogen and carbon dynamics after forest fires (Article link).

Did you know that ground squirrels have lice – and males have more than females? Neither did we, but Matt Yunick and colleagues (University of Manitoba) recently published an article in The Canadian Entomologist describing their findings (Article link).

Boyd Mori and Dana Sjostrom (University of Alberta) were part of a group of researchers that found that pheromone traps are less effective at high densities of forest tent caterpillars because of competition for pheromone plumes (Article link).

Parasitoid memory dynamics are affected by realistic temperature stress. As part of a collaboration with the University of Palermo (Italy), Paul Abram (Université de Montréal) and colleagues discovered that both hot and cool temperature cycles prevent wasps (Trissolcus basalis) from forgetting. (Article link).

Trissolcus basalis (Hymenoptera: Platygastridae) parasitizing the eggs of its host Nezara Viridula (Hemiptera: Pentatomidae). These parasitoids can detect their host's

Trissolcus basalis (Hymenoptera: Platygastridae) wasps (left panel) parasitizing the eggs of their host stink bug Nezara viridula (Hemiptera: Pentatomidae; mating couple shown in right panel). These parasitoids can detect their host’s “chemical footprints”, and even commit them to memory! (Photos: Antonino Cusumano)

Crisia Tabacaru and Sarah McPike (University of Alberta) studied Dendroctonus ponderosae and other bark and ambrosia beetles and found that competition between the beetles may limit post-fire colonization of burned forest stands (Article link).

Marla Schwarzfeld (University of Alberta) found that tree-based (GMYC and PTP) species delimitation models were less reliable in delimiting test species, and the Nearctic Ophion (Hymenoptera: Ichneumonidae) fauna is much larger than previously thought (Article link).

Where have all the mosquitoes gone? Emily Acheson and colleagues (University of Ottawa) found spatial modelling reveals mosquito net distributions across Tanzania do not target optimal Anopheles mosquito habitats (Article link).

Tyler Wist and colleagues (University of Alberta) found that a native braconid parasitoid (Apanteles polychrosidis) uses host location cues induced by feeding damage on black ash but not on green ash (Article link). Also check out the author’s recent post on the ESC Blog!

Fig. 2 Female Apanteles polychrosidis Viereck (Hymenopetra: Braconidae)

Fig. 2 Female Apanteles polychrosidis Viereck (Hymenopetra: Braconidae) (Photo: Tyler Wist).

Agriculture

Sharavari Kulkarni and colleagues (University of Alberta) discovered that reducing tillage could increase the amount of weed seeds consumed by carabid beetles (Article link).

Physiology and Genetics

Sebastien Boutin and colleagues (Université Laval) are beginning to decode the genetic basis of honeybee hygenic behaviour (Article link).

Investigating the cold tolerance of different Sierra leaf beetle life stages, Evelyn Boychuk and colleagues (University of Western Ontario) found that adults are freeze tolerant, the eggs and pupae are freeze-avoidant, and the larvae are chill susceptible (Article link).

From the Authors:

Shaun Turney, Elyssa Cameron, and Chris Cloutier had this to say about their new article published in PeerJ:

Our supervisor, Prof. Chris Buddle, has always emphasized the importance of voucher specimens for our entomology research. He explained that voucher specimens make our work replicable and verifiable. We wondered how widespread the practice of making voucher specimens among those practicing arthropod-based research. We investigated the frequency of voucher deposition in 281 papers, and the factors which correlated to this frequency. Surprisingly, vouchers were deposited less than 25% of the time! Our paper highlights the need for a greater culture of voucher deposition and we suggest ways in which this culture can be cultivated by researchers, editors, and funding bodies.

Voucher specimens: an important component of arthropod-based research (Photo provided by Shaun Turney, Elyssa Cameron, and Chris Cloutier)

Voucher specimens: an important component of arthropod-based research (Photo provided by Shaun Turney, Elyssa Cameron, and Chris Cloutier)

From Ikkei Shikano, on two of his recently published articles:

Parents that experience a stressful environment can equip their offspring to fare better in a similar environment. Since this can be energetically expensive for the parent, we asked if parents are exposed to two stressors (nutritional stress and a pathogen), would they equip the offspring for both stressors or would they select one over the other? Cabbage looper moths exposed to a pathogen and poor food quality produced offspring that were highly resistant to that same pathogen. Parents that were given poor food produced offspring that developed faster on poor food. When the parents experienced both stressors, they produced offspring that were resistant to multiple pathogens but did not grow faster on a poor diet (Article link).

Herbivorous insects unavoidably eat large and diverse communities of non-entomopathogenic microbes, which live on the surface of their host plants. Previous studies suggest that consuming non-entomopathogenic bacteria may induce a costly immune response that might decrease the risk of infection by pathogens. But isn’t it wasteful for an insect upregulate a costly immune response to non-pathogens that it ingests with every meal? Within an appropriate ecological context, we show that cabbage looper, Trichoplusia ni, larvae do not induce a costly immune response, indicating that they are adapted to consuming non-pathogenic bacteria that are commonly found on the surface of their host plants (Article link).

From Kate Pare, on an article published by a group of undergraduates taking the Arctic Ecology field course at the University of Guelph:

Our study focused on changes in ant diversity in the area surrounding Churchill, Manitoba between the historic collections made by Robert E. Gregg in 1969 and collections made by students and instructors of the Arctic ecology field course in 2012. Seven ant species were collected in 2012 compared to the five species recorded from 1969. This increase in species richness in the 2012 collection is more likely a result of cryptic molecular diversity that was overlooked in the collection made in 1969 (Article Link, post on the ESC blog).

Members of the Arctic Ecology Field course 2015 (Photo: Eric Scott)

Members of the Arctic Ecology Field course 2015 (Photo: Eric Scott).


The ESC Student Affairs Committee will be continuing to help publicize graduate student publications to the wider entomological community through our Research Roundup. If you published an article recently and would like it featured, e-mail us at entsoccan.students@gmail.com.

For regular updates on new Canadian entomological research, you can join the ESC Students Facebook page or follow us on Twitter @esc_students.

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Differential parasitism and ash tree volatile organic chemicals

By Tyler Wist  

The ash leaf cone roller, Caloptilia fraxinella (Ely) (Lepidoptera: Gracillaridae) (Fig. 1) started to get noticed in the cities of the Western Canadian prairies in 1998, well, in Saskatoon, SK at least. I know this because that summer the green ash, Fraxinus pennsylvanica (Oleaceae), in my front yard was covered in cone rolled leaflets and had not been prior to that year. I had just started working for the City of Saskatoon’s Pest Management Program that year and one of our mandates was urban forest insects…not that there was any budget to control them, but it piqued my interest in urban forest entomology.

Fig. 1 The ash leaf coneroller, Caloptilia fraxinella (Ely) (Lepidoptera: Gracillaridae) adult, pupal exuvium and cocoon.

Fig. 1 – The ash leaf coneroller, Caloptilia fraxinella (Ely) (Lepidoptera: Gracillaridae) adult, pupal exuvium and cocoon.

The following year, Chris Saunders with the City of Edmonton’s Pest Management Program, contacted us in Pest Management and asked if we had seen this cone roller on our ash trees because they had just noticed it on the ash trees in Edmonton. Greg Pohl had identified this leaf miner/leaf roller that year on all species of horticultural Fraxinus in Edmonton and published the identification and some life history of the moth in a 2004 paper (Pohl et al. 2004) along with a brief identification of several parasitoids that were reared from larvae and pupae. The lone braconid, identified to the genus Apanteles and found to be all one species by Darryl Williams of the Canadian Forest Service in Edmonton seemed to be the dominant parasitoid in this complex, but without a species designation not much else about the wasp could be gleaned from the literature.

Chris Saunders suggested that I study the ash leaf cone roller as a master’s project but I digressed from urban forest entomology for a few years into pollination of a nutraceutical/agricultural crop. By this time, the ash leaf cone roller had spread to every ash tree in both cities and often rolled 100% of the leaflets on a single tree. I finally followed Chris’ advice and started a PhD project in Maya Evenden’s lab at the University of Alberta, which was the only lab in Canada that was working on the ash leaf cone roller problem (Evenden 2009). The Apanteles sp. was still the dominant parasitoid and so, along with studies on the chemical ecology of the moth (Wist et al. 2014), I also studied the third trophic level in this system (Wist and Evenden 2013). Of course, I couldn’t go through my studies without knowing what the species designation was for the dominant parasitoid wasp. Fortunately, Jose Fernandez-Triana had just begun his study of the genus Apanteles at the CNC in Ottawa and once Henri Goulet passed along the Apanteles specimens that I had sent for identification he quickly determined that this parasitoid was Apanteles polychrosidis Viereck (Hymenopetra: Braconidae) (Fig. 2).

Fig. 2 Female Apanteles polychrosidis Viereck (Hymenopetra: Braconidae)

Fig. 2  – Female Apanteles polychrosidis Viereck (Hymenopetra: Braconidae)

Apanteles polychrosidis kills the ash leaf cone roller larvae before they can chew their emergence “window” that they use to escape the cone rolled leaflet as adults. This behaviour gives a fairly reliable visual cue that a cone rolled leaflet without a “window” has been parasitized by A. polychrosidis because the other parasitoids in the complex emerge after the cone roller has pupated and created its escape route “window”. Unrolling the leaflet confirms the presence of A. polychrosidis if its telltale “hammock-like” cocoon is present (Fig. 3). This type of cocoon is thought to be a defense against hyper-parasitism but as we found (Wist and Evenden 2013) it doesn’t always work out for A. polychrosidis!

Fig. 3 Apanteles polychrosidis Viereck (Hymenopetra: Braconidae) adult above its cocoon and beside the leaflet cone rolled by Caloptilia fraxinella (Ely) (Lepidoptera: Gracillaridae). Note the emergence hole in the side of the leaflet that the wasp chewed to escape.

Fig. 3 – Apanteles polychrosidis Viereck (Hymenopetra: Braconidae) adult above its cocoon and beside the leaflet cone rolled by Caloptilia fraxinella (Ely) (Lepidoptera: Gracillaridae). Note the emergence hole in the side of the leaflet that the wasp chewed to escape.

To assess the percentage of parasitism by this dominant parasitoid I adapted a method that Chris Saunders and I had discussed years earlier for assessing the parasitism of Apanteles sp. on individual trees. For the initial experiment in our paper (Wist et al. 2015) I sampled leaflets to estimate the density of cone rollers on the tree and estimated the percentage of parasitism by A. polychrosidis on two of the common urban species of ash in Edmonton. Apanteles polychrosidis parasitism was higher on black ash, F. nigra, at all sites than it was on green ash, F. pennsylvanica, which can be called differential parasitism and it seems to be common when host larvae develop on two or more host plants, but had not been well studied on trees. When host density and parasitism were graphed, the relationship of parasitism to host density could be visualized by the slope of the regression line, and on black ash, parasitism was independent of host density on black ash, but was negatively density dependent on green ash. In other words, on black ash parasitism is always high but on green ash, parasitism declines as the density of C. fraxinella increases. I ran the same experiment on green and black ash trees in Saskatoon with the same results but we chose to leave them out of the final version of the manuscript.

I was already studying the chemical ecology of C. fraxinella so this was where we looked for an answer to the differential parasitism in the field. I ran a y-tube olfactometer experiment with black and green ash plant material as the attractive source of volatile organic chemicals (VOCs) and this turned out to be rather tricky. I had three treatments that I wanted to test; undamaged leaflets, leaflets damaged by C. fraxinella and leaflets that were mechanically damaged.

First, I tried to bag small seedlings as the source of the plant smell but I couldn’t seal the system well enough to get reliable airflow through the y tube chamber. I had to switch to using leaflets alone which raises the issue of the smell of the leaflets changing once they have been removed from the tree which could be a problem especially in the “undamaged” treatment. I also needed enough female A. polychrosidis hunting for hosts to give me a decent sample size so I had to collect and emerge as many “un-windowed” cone-rolled leaflets as I could in the summer, and hope that they would actually mate and want to oviposit into host larvae at this point in their lives. Another issue was that I couldn’t coax my summer emerged C. fraxinella to lay eggs on ash seedlings to create leaf-mined treatments. Fortunately, a subset of the local population of C. fraxinella had developed a second generation on the new ash leaves that a dying ash tree puts out in July in an effort to save itself. These leaflets became my leaf-mined treatment. Over two seasons with a lot of juggling and timing of three species I was able to gather enough experimental data with the olfactometer to discover that female A. polychrosidis were differentially attracted to the volatile odour cues from each ash species. In green ash tests, they were attracted to the smell of green ash alone but in black ash tests, they were not attracted unless the leaflets were attacked by its host. The “icing on the manuscript cake” was the GC-EAD results by co-authour Regine Gries that showed that 13 compounds in the volatile profile of ash could be sensed by the antennae of A. polychrosidis, and some of them are known to increase in response to herbivore damage.

I’d say that this manuscript is a starting point for further studies on this interesting parasitism system and could accommodate projects from chemical ecology and landscape ecology perspectives at the very least. In fact, Danielle Hoefele and Sarah McPike have already begun projects in Maya’s lab on the FraxinusCaloptilia-Apanteles system. In case you’d like to know more, here is the link to our manuscript published in Arthropod-Plant Interactions.

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From inquiring students to published authors: an adventure in the Arctic

by Amanda Boyd and Kate Pare

The field course in Arctic Ecology (BIOL*4610), offered periodically by the University of Guelph, explores ecological relationships in a sub-arctic environment. Based out of the Northern Studies Research Center, the 2-week course takes place in Churchill Manitoba and the surrounding area. That was what we, the students, knew going into the course. What we didn’t know was that course would be, for many of us, a once in a lifetime experience!

Students in the Arctic Ecology field course learning from Hymenopterist extraordinaire Alex Smith

Students in the Arctic Ecology field course learning from hymenopterist extraordinaire Alex Smith. (Photo by Eric Scott) 

There are only three ways of travelling to Churchill, Manitoba: by boat, by plane or by train. Since we wouldn’t be taking the boat route, two options were left: an hour and forty-minute flight, or a three-day journey by rail. The latter is where most of our adventures began (particularly when some of us didn’t purchase a sleeper ticket). There is much to be learned from a long northward trek, from changing ecosystems and changing cultural environments to increasing price tags. Eventually though, the journey’s end came with a comfortable bus ride and an incredibly delicious meal at the Northern Studies Centre. From there on out, it was down to business.

The first week of our course was spent roaming the rugged landscape, learning about the diverse ecosystems the region has to offer while simultaneously trying to prevent ourselves from being carried off by the swarms of (seemingly) abnormally-sized horse flies. We visited sphagnum bogs, fens, the coast (which may have involved kayaking with belugas), a cranberry-laden moraine and the northern extent of the boreal forest. We explored Krummholtz and bluffs, learned that sedges have edges and learned to always be on the lookout for polar bears (at least 2 bear guards please!). The second week however, allowed us the liberty of designing and conducting our own studies.

As a real world example of scientific research in action, the first day of week-two was spent sampling in the footsteps of Robert E. Gregg and collecting ants from his original 1969 study sites (Gregg 1972). Armed with basic instructions on the identification of the 1969 sampled ant species and genera, we visited a total three sites: Cape Merry, the Churchill Welcome Sign, and Goose Creek Bog. At each site, we spent approximately three hours actively searching for ants, breaking open woody debris and digging into moss hummocks. This was true for all but the Goose Creek site where our (brand new bus) tire sprung a leak and we had no choice but to wait there (which may have resulted in a thoroughly sampled population of Odonates) until Alex Smith, one of the instructors walked into town to radio the Churchill Northern Studies Centre for Plan-B transportation. From there it was back to the lab for a crash course on identifying ants to morphospecies, and for many of us, a valuable lesson that all individuals of a species do not look the same (due to individual variation and cryptic diversity). The rest of week-two was spent with groups of students at every site chasing a variety of six-legged, sub-arctic mysteries. Of course, as students of the natural world, no curiosity was overlooked and no opportunity for fun either! Many an hour was spent bluff jumping, polar bear sighting, investigating the Ithaca shipwreck, and in the case of some students, completing a partial reconstruction of an arctic fox skeleton. Needless to say, it was a very short two weeks that passed with discovery and awe.

One of the many species collected - an ant in the Leptothorax muscorum complex, collected at Cape Merry (Photo by Chelsie Xavier-Blower)

One of the many species collected – an ant in the Leptothorax muscorum complex, collected at Cape Merry (Photo by Chelsie Xavier-Blower)

Going into our field course, I’m not sure any of us thought we would come out of it as published authors. For many of us that participated, the Arctic Ecology field course provided the first real opportunity to actively participate in research outside of the university. The idea that a few days’ worth of collections could be turned into a scientific paper was almost unimaginable. The resulting paper was the first publication that any of us had contributed to. It was exciting to receive the manuscript drafts, and then paper proofs and to know that even aspiring researchers like us could contribute to the knowledge of the scientific community.

During the course, we took high-resolution panoramic GigaPan photographs of the areas we sampled (Smith et al 2013) – you can explore those here. All the DNA barcodes we generated during the course are publicly available for download and exploration. Finally, we wrote about using GigaPans in our Churchill adventures in an article for GigaPan Magazine.

Members of the Arctic Ecology Field course 2015

Students of the Arctic Ecology Field course (now published authors!)(Photo by Eric Scott)

Acknowledgements

We would like to thank LeeAnn Fishback and the staff of the Churchill Northern Studies Centre (https://www.churchillscience.ca/) for all their hospitality and help in Churchill. Support from the CREATE Lab Outreach Program at Carnegie Mellon University, the Learning Enhancement Fund of the University of Guelph (http://www.lef.uoguelph.ca/) and the Fine Foundation helped provide funds for GigaPan-ing and DNA barcoding during the course. Support from the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI) to Alex Smith and Sarah Adamowicz provided support and infrastructure.

References

Gregg, R.E. 1972. The northward distribution of ants in North America. The Canadian Entomologist, 104: 1073–1091

Smith, M. Alex, S. Adamowicz, Amanda Boyd, Chris Britton-Foster, Hayley Cahill, Kelsey Desnoyers, Natalie Duitshaever, Dan Gibson, Steve James, Yurak Jeong, Darren Kelly, Eli Levene, Hilary Lyttle, Talia Masse, Kate Pare, Kelsie Paris, Cassie Russell, Eric Scott, Debbie Silva, Megan Sparkes, Kami Valkova (2013) “Arctic Ecology” GigaPan Magazine Vol 5 Issue 1. www.gigapanmagazine.org/vol5/issue1/  (students ordered alphabetically)

Smith, M. Alex, Amanda Boyd, Chris Britton-Foster, Hayley Cahill, Kelsey Desnoyers, Natalie Duitshaever, Dan Gibson, Steve James, Yurak Jeong, Darren Kelly, Eli Levene, Hilary Lyttle, Talia Masse, Kate Pare, Kelsie Paris, Cassie Russell, Eric Scott, Debbie Silva, Megan Sparkes, Kami Valkova S. J. Adamowicz  (2015) The northward distribution of ants forty years later: re-visiting Gregg’s 1969 collections in Churchill, Manitoba, Canada. The Canadian Entomologist. http://dx.doi.org/10.4039/tce.2015.53

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When you’re a spined soldier bug laying eggs, they can be “Any Colour You Like”

By Paul Abram
PhD Student, Université de Montréal

When Pink Floyd recorded their epic, psychedelic instrumental “Any Colour You Like” for the classic album Dark Side of the Moon, were they inspired by a predatory stink bug?

Three spined soldier bugs happily eating a mealworm.  Their voracious appetite makes them a widely-used biological control agent of insect pests (Photo credit: Andrea Brauner).

Three spined soldier bugs happily eating a mealworm. Their voracious appetite makes them a widely-used biological control agent of many different insect pests (Photo credit: Andrea Brauner).

Well … probably not.

The spined soldier bug (Podisus maculiventris), can’t actually lay any colour of egg it likes – but the real range of possibilities is pretty impressive.

The range of possible egg colours that can be laid by a single female spined soldier bug (Photos: Paul Abram/Eric Guerra)

The range of possible egg colours that can be laid by the spined soldier bug (Photo credit: Paul Abram/Eric Guerra)

Almost three years ago, when I started working with stink bugs and their parasitoid wasps, I noticed this astounding variation in the colour of the eggs of the spined soldier bug. I was surprised to find that nobody had looked into the cause of this variation or its potential functions. In fact, the function of insect egg colouration seems to have been a bit neglected in general. While I was initially hesitant to start on the dangerous path towards a PhD “side-project” (code for “I would like to take much longer to finish my degree, please”), I eventually caved.

In 2013, I was visiting a colleague’s lab where newspapers are used as a laying substrate for these bugs, and I noticed that there seemed to be a loose correspondence between the colour of the egg masses and the darkness of the paper, especially in high-contrast places like crossword puzzles. I wondered – could stink bugs actually adjust the coloration of their eggs to match the darkness of the laying surface? If so, this would be the first case of an animal able to selectively control the colouration of its eggs.

Back in Montreal a few months later, I started working on this question with an undergraduate summer student, Marie-Lyne Desprès-Einspenner. We did the simple experiment of putting individual females in Petri dishes painted white, black, or black on one side and white on the other.

Petri dishes housing spined soldier bug females, along with a mate, prey, and some green bean.  Everything a stink bug needs! (Photos: Paul Abram)

Painted dishes housing spined soldier bug females [right], along with a mate, prey, and some green bean [opened dish shown on the left]. (Photos: Paul Abram)

To our surprise and excitement, we got some nice results. First of all, it was clear that individual stink bugs could lay eggs across the whole spectrum of egg colours, and that the egg colour variation wasn’t just a result of advancing egg development. Additionally, stink bugs tended to lay darker eggs in the black petri dishes than the white ones; and, in the bi-coloured dishes, overall darker eggs on the black side than the white side. These effects were subtle, though, compared to the most important and unexpected factor: where the eggs were laid. Eggs tended to be lighter when laid on the underside of the lid (which was lit up from above) than when laid on the side or the bottom of dishes.

So, individual stink bugs can lay eggs of a range of colours, depending on where they are laying. Our next question was: how does this capability express itself on natural laying surfaces? We did some experiments using soybean plants, and figured out what seems to be the key to this whole thing: the stink bugs have a very strong tendency to lay darker-coloured egg masses on the tops of leaves (which have a relatively low surface brightness, like our black dishes), and lighter-coloured masses on leaf undersides (which have a high surface brightness due to light passing through from above, similar to the lids of our white dishes).

Light eggs laid on a leaf underside (upper panel), and dark eggs laid on a leaf top (lower panel). Photo credit: Leslie Abram.

A light egg mass laid on a leaf underside (upper panel), and a dark egg mass laid on a leaf top (lower panel). Photo credit: Leslie Abram.

Because leaves are excellent filters of ultraviolet (UV) radiation from the sun (protecting most insect eggs, which are usually laid on leaf undersides), and dark pigmentation often acts as a ‘sunscreen’ in nature, we wondered if dark colouration would protect developing stink bug eggs from a lethal sunburn when they are laid on the tops of leaves. Eric Guerra-Grenier (another undergraduate researcher in the lab) and I tested this in the lab by exposing differently coloured eggs to different doses of sun-mimicking UV radiation.

The results were crystal clear – darker eggs are better-protected from UV radiation than light eggs, with a strong dose-dependency with respect to UV radiation intensity and egg colouration.

This was an exciting find, but begged the question: what is the pigment that makes eggs dark, anyway? The clear answer was that it must be melanin, which is responsible for most dark animal pigmentation, including in us humans, and is also really good at protecting against UV radiation damage.

Eric and I did the obvious thing, sending hundreds of (freezer-killed) stink bug eggs to two melanin biochemists in Japan. Our collaborators ran a suite of tests to confirm that the egg pigment was melanin. But…it turned out that the egg pigment wasn’t melanin! Right now, we simply don’t know what this “mystery pigment” is (maybe something totally new to science?).

As is common in research, we are left with more questions than answers. What is the physiological mechanism that allows stink bugs to selectively apply pigment to eggs? In evolutionary terms, why lay eggs on UV-exposed leaf tops in the first place? And why still lay some light eggs on leaf undersides? Could the pigment also have a role in camouflage, thermoregulation, or water retention? Do other, closely related (or why not distantly-related) insect species also have this capacity? We’re currently working on some of these questions, and I hope that we get to try to answer all of them eventually.

If you’d like, you can find a lot more details about our findings, including the answer to “does UV radiation affect the control of egg colour?”, in a newly published paper (remember to listen to the accompanying song while reading) – and stay tuned for more results in the coming months.

In the meantime, fellow entomologists and naturalists, look closely at insect eggs – is there anything interesting about how they’re coloured/patterned?

A spined soldier bug female having a drink and contemplating the future of insect egg colour research (Photo credit: Leslie Abram)

A spined soldier bug female having a drink and contemplating the future of insect egg colour research (Photo credit: Leslie Abram)


Postscript:

I would like to suggest additional Pink Floyd song/entomology paper pairings (feel free to suggest your own!):

“Breathe” //  “Active Regulation of Insect Respiration”

“Run Like Hell” //  “Mechanics of a rapid running insect: two-, four- and six-legged locomotion”

“Mother” // “Parental care trade-offs and the role of filial cannibalism in the maritime earwig, Anisolabis maritima

“Echoes” // “The adaptive significance of host location by vibrational sounding in parasitoid wasps”

“Time” // “Short interval time measurement by a parasitoid wasp”

“Us and Them” // “Boundary disputes in the territorial ant Azteca trigona: effects of asymmetries in colony size”

“Comfortably Numb” // ”Effects of carbon dioxide anaesthesia on Drosophila melanogaster

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The flight of the backswimmer: dispersal behaviour in a freshwater insect

By Celina Baines

Have you ever thought about what a pond-dwelling insect might do if it doesn’t like the pond it lives in? People generally assume that these insects are stuck where they are, but actually, many freshwater insects have wings and can fly. This movement between ponds is an example of a process known as dispersal.

Backswimmers, for example, are insects that live in ponds and streams (and sometimes even swimming pools!). Backswimmers have a characteristic way of swimming – on their backs, just under the surface of the water, using their hind legs to propel themselves. It makes them look a little like they are doing the backstroke (hence their common name!). But they also have wings, and can fly between ponds.

A top view of a backswimmer swimming. Backswimmers can often be seen swimming just under the surface of the water, ventral side up. Photo credit: Shannon McCauley.

A top view of a backswimmer swimming. Backswimmers can often be seen swimming just under the surface of the water, ventral side up. Photo credit: Shannon McCauley.

We know from observing these insects that not all backswimmers make the same decisions about whether to disperse. Some individuals spend their whole lives in the ponds they are born in, and some individuals move to new ponds. So why do some individuals stay and some leave? One factor that could influence dispersal decisions is the quality of the pond. Pond “quality” could depend on many things, including the risk of being eaten by predators like fish. Dispersing can be a great way for organisms to avoid habitats that will be bad for them or their offspring.

Once a backswimmer has decided that it wants to disperse, it then has to decide whether it is strong and healthy enough to fly. This could be another factor that determines whether an individual decides to stay or go.

In the summer of 2013, I conducted a field experiment to learn more about how backswimmers make dispersal decisions. I wanted to test whether dispersal was induced by fish. I also wanted to test whether body condition (basically, the general strength and health of an organism) influences dispersal decisions.

I started by collecting backswimmers from a pond at the Koffler Scientific Reserve. That’s a research site owned by the University of Toronto, where I’m a graduate student.

This is me collecting backswimmers from a pond at the Koffler Scientific Reserve. Photo credit: Chris Thomaidis.

This is me collecting backswimmers from a pond at the Koffler Scientific Reserve. Photo credit: Chris Thomaidis.

I brought the backswimmers back to a lab at the University of Toronto. Because I wanted to test the effects of body condition on dispersal, I first had to manipulate the backswimmers so that they had different levels of body condition. I did this by carefully controlling how much food each backswimmer got to eat.

Backswimmers are carnivores, and they aren’t very picky. For this experiment, I fed them fruit flies, because it’s really easy to get lots and lots of fruit flies. So, in what turned out to be one of the most back-breakingly tedious jobs I’ve ever performed for science, I (and many uncomplaining assistants) counted out thousands of individual fruit flies to feed to the backswimmers. Each backswimmer was housed in its own little cup, and received a specific (and carefully counted) number of fruit flies to eat every day. Here’s what the hundreds of drink cups looked like, colour coded and full of bugs.

Left: Cups housing backswimmers at the University of Toronto. Right: A backswimmer in its cup.

Left: Cups housing backswimmers at the University of Toronto. Right: A backswimmer in its cup.

After a few weeks of controlling the backswimmers’ diets, it was time to bring them outside to see if they would fly. I set up some artificial ponds in a big field. These “ponds” are actually just watering tanks that farmers use for cows and horses, but I added algae and artificial plants to make them more like natural ponds. Since I also wanted to test whether backswimmers are scared away by fish, I added a fish to half of the tanks. I put the fish in cages, and that way, the backswimmers could tell there was a fish in the tank (they could see and smell the fish), but the fish couldn’t actually eat the backswimmers.

This is me, checking the artificial ponds for backswimmers. Photo credit: Betty Dondertman.

This is me, checking the artificial ponds for backswimmers. Photo credit: Betty Dondertman.

Then I put the bugs in the tanks, and waited. After a couple days, I went back to the tanks and checked to see which backswimmers were still in the tanks, and which ones had flown away.

Firstly, I found that backswimmers are scared away by fish; they are more likely to disperse when a fish is in their pond.

I also found that the backswimmers with high body condition are more likely to fly, probably because they are strong fliers and have the best chance of successfully finding a new pond.

Both of these results were really cool and answered some questions for us about how backswimmers make dispersal decisions. But they might also tell us a little about how other organisms move around in natural ecosystems. Dispersers are the only individuals that can find new ponds and start new populations. If dispersers tend to be the strongest and healthiest individuals, that’s great for native species that we want to encourage to start new populations. But having strong, healthy individuals from exotic species start new populations is probably bad news. Dispersal can therefore have important consequences, which is why we need to understand more about how and why organisms disperse.

For more information about my study, check out the recent publication:

Baines, C. B., McCauley, S. J., & Rowe, L. (2015). Dispersal depends on body condition and predation risk in the semi‐aquatic insect, Notonecta undulata. Ecology and Evolution 5(12): 2307–2316

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Canadian Entomology Research Roundup: April – June 2015

As a graduate student, publishing a paper is a big deal. After spending countless hours doing the research, slogging through the writing process, soliciting comments from co-authors, formatting the paper to meet journal guidelines, and dealing with reviewer comments, it’s nice to finally get that acceptance letter and know that your work is getting out there. The ESC Student Affairs Committee is happy to be posting a fourth roundup of papers authored by Canadian graduate students. Stay tuned to the ESC blog for some full length guest posts from some of the students below in the coming weeks!

Have a look at what some entomology grad students in Canada have been up to recently! Articles below were published online from April through June 2015.

Forestry

Seehausen et al. found that parasitism of hemlock looper Lambdina fiscellaria (Guenée) (Lepidoptera: Geometridae) pupae was significantly reduced in plots with high partial cutting intensities (40%). To sustain parasitism rates in forest stands vulnerable to hemlock looper defoliation at naturally high levels, it is recommended to refrain from high intensity partial cutting. Article link

Apechthis Ontario parasitizing a hemlock looper pupa (Photo credit: Lukas Seehausen)

Apechthis ontario parasitizing a hemlock looper pupa (Photo credit: Lukas Seehausen)

During its recent outbreak starting in the early 2000s, the mountain pine beetle destroyed huge areas of lodge pole pine forests in BC and Alberta while also expanding its geographic range east and north. More recently, the beetle has been confirmed to be attacking and reproducing in a novel host, jack pine, which is distributed from Alberta to the Atlantic coast. New research by Taft et al. looks at how specific chemicals in jack pine trees that affect mountain pine beetle vary in jack pine across its range. Article link

Another study from the Erbilgin lab at University of Alberta by Karst et al. revealed that stand mortality caused by prior beetle attacks of mature pines have cascading effects on seedling secondary chemistry, growth and survival, probably mediated through effects on below-ground mutualisms. Article link

Physiology and Genetics

Proshek, Dupuis, et al. found the genetic diversity of Mormon Metalmark species complex are more diverse than traditional morphological characters. Article link

A Lange Metalmark butterfly (Photo: Wikimedia Commons)

Oudin, Bonduriansky, and Rundle at the University of Ottawa found the amount of sexual dimorphism present in antler flies is condition-dependent. Article link

Nearby at Carleton University, Webster et al. studied the edge markings on moths to show they can provide camouflage by breaking up their body outline. Article link

Another study from Carleton University, from Hossie et al., showed that predator-deterring eyespots tend to appear on larger-bodied caterpillars and that smaller species are better off remaining undetected. Check out the detailed blog post about this study on the lead author’s blog, and a great photo gallery of caterpillars with eyespots! And here’s the link to the Article.

Jakobs, Gariepy, and Sinclair established that adult phenotypic plasticity is not sufficient to allow Drosophila suzukii to overwinter in temperate habitats. Article link

Insect Management

Part of the PhD work of Angela Gradish focused on the White Mountain arctic butterfly (WMA), a very rare butterfly occurring only on the alpine zone of Mts. Washington and Jefferson in New Hampshire. Despite its threatened status, little was known of the WMA’s population structure, distribution, and behaviour. So Gradish grabbed a net and headed up Mt. Washington, where she spent part of two summers collecting WMA samples for genetic analyses while performing a mark-release-recapture study on the population. She was the first to use genetic analyses to study the WMA, the results of which are presented here.  Find the results of the mark-release-recapture study here.

Angela Gradish collecting

Collecting butterflies on Mount Washington (photo credit: Angela Gradish).

Marshall and Paiero, from the Marshall lab at University of Guelph, gives a new record of a Palaearctic leaf beetle, Cassida viridis, which has been present in Ontario since 1974. Article link

Maguire et al., from the Buddle lab at McGill University, found destructive insect herbivores can positively or negatively impact ecosystem services depending on outbreak conditions. Article link

Biodiversity

Ernst and Buddle discovered that the diversity and assemblage structure of northern carabid beetles show strong latitudinal gradients due to the mediating effects of climate, particularly temperature. Article link

Behaviour and Ecology

The Luong lab at University of Alberta observed that ectoparasitic mites have deleterious effects on host flight performance of Drosophila species. Article link

Therrien et al. from the Erbilgin lab at the University of Alberta found that bacteria can influence brood development of bark beetles in host tissue. Article link

Desai, Kumar, and Currie from the Currie lab at the University of Manitoba conducted the first major baseline study of viruses in Canadian honey bees to show that deformed wing virus has the highest concentration among worker bees. Article link

Baines, McCauley, and Rowe from the Rowe lab at University of Toronto showed that dispersal is a positive function of body condition in backswimmers, but not interactive with predation risk. Article link

Backswimmers can often be seen swimming just under the surface of the water, ventral side up (Photo credit: Shannon McCauley).

Backswimmers can often be seen swimming just under the surface of the water, ventral side up (Photo credit: Shannon McCauley).

Strepsiptera is a peculiar and enigmatic insect order. All are entomophagous endoparasitoids. Unusually for parasitoids, they possess a very broad host range, encompassing 7 orders and 34 families of insects, in various habitats worldwide. Despite their broad host range, and cosmopolitan distribution, surprisingly little is known about their biology. The gaps in knowledge of this group has led to many generalizations about their biology and behaviour. Only recently are studies beginning to uncover a hitherto unforeseen diversity in reproductive strategies. In this review, Kathirithamby, Hrabar, and colleagues discuss the reproductive biology of Strepsiptera: what is known, and what mysteries remain to be solved. Article link

In the Sargent lab at University of Ottawa, Russell-Mercier and Sargent investigated herbivore-mediated differences in floral display traits and found that they impacted pollinator visitation behaviour, but not in female reproductive success. Article link

Techniques

Can you use gut content DNA analysis of a staphilinid beetle to track predation of spotted wing drosophila? Here’s what Renkema et al. found.

Rosati et al., from the Vanlaerhoven lab at University of Windsor, discuss using ImageJ software to quantify blow fly egg deposition in a non-destructive manner. Article link

We are continuing to help publicize graduate student publications to the wider entomological community through our Research Roundup. Find the previous edition here: http://escsecblog.com/2015/05/04/canadian-entomology-research-roundup-march-2015-april-2015/. If you published an article recently and would like it featured, e-mail us at entsoccan.students@gmail.com. You can also send us photos and short descriptions of your research, to appear in a later edition of the research roundup.

For regular updates on new Canadian entomological research, you can join the ESC Students Facebook page or follow us on Twitter @esc_students

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Canadian Entomology Research Roundup: March 2015 – April 2015

As a graduate student, publishing a paper is a big deal.  After spending countless hours doing the research, slogging through the writing process, soliciting comments from co-authors, formatting the paper to meet journal guidelines, and dealing with reviewer comments, it’s nice to finally get that acceptance letter and know that your work is getting out there. The ESC Student Affairs Committee is happy to be posting a third roundup of papers authored by Canadian graduate students. Stay tuned to the ESC blog for some full length guest posts from some of the students below in the coming weeks!


Here’s what some entomology grad students in Canada have been up to recently (Articles published online in March and April, 2015):

Ecology and Evolution

All species are variable and are constantly evolving but we simply do not know how ecologically important this is. Nash Turley and colleagues at the University of Toronto Mississauga showed that genetic variation and evolution over the course of a month in a rapidly reproducing insect herbivore (green peach aphid) plays large roles in shaping the growth of plants they feed on. This suggests that genetic and ongoing evolutionary processes are important to consider when trying to understand the ecological effects of interactions among species. Article link

Top: Different genotypes of the green peach aphid; Bottom: A field experiment to test the effect of contemporary aphid evolution on plants

Top: Different genotypes of the green peach aphid; Bottom: A field experiment to test the effect of contemporary aphid evolution on plants (photos provided by Nash Turley)

Emsen Hamiduzzaman (University of Guelph) and colleagues compared viral infection rates between honey bee colonies with high and low rates of parasitic mite population growth. Article link

Many of the 5,000+ bark beetle species produce acoustic signals to communicate with the opposite sex, but the question that has never before been answered is, what are they trying to say? Amanda Lindeman and Jayne Yack (Carleton University) determined that these signals likely communicate the signaller’s fitness and are the proverbial password that encourages a female to step aside and grant a male admittance to her gallery. Article link

A male red turpentine beetle at the entrance to a female’s gallery. Female is visible blocking the gallery entrance

A male red turpentine beetle at the entrance to a female’s gallery. Female is visible blocking the gallery entrance (photo provided by Amanda Lindeman).

Mating experience matters! Joanna Konopka (Western Univeristy) found that Western bean cutworm moth females with more than one mating experience are ready to go again sooner, with a shorter refractory period and earlier onset of calling. Article link

‘Bee hotels’ are nesting habitat analogues of cavity-nesting bees and wasps. These devices are great research and monitoring tools, but more recently, concern for declining bee populations has led to their commercialization and conveyance as a means to ‘save the bees’ and house native pollinators. In a study conducted by Scott MacIvor (University of Toronto), 600 bee hotels were used to sample populations and found that 50% of colonizers were wasps and another 25% were exotic bees. Further, native bees were parasitized significantly more often than exotic bees. Many native bees use bee hotels but communicating the diversity of occupiers is needed to avoid ‘bee-washing’. Article link

Nestbox JSM

A ‘bee hotel’ nest box (photo provided by Scott MacIvor).

A molecular phylogeny of Taeniapterini (Stilt-legged flies, Micropezidae) created by Morgan Jackson and colleagues (University of Guelph) leads to a reclassification of the large genus Taeniaptera and the resurrection two genera. Article link

Aaron Hall (University of Toronto) and colleagues found that recreational boating pressure affects dragonfly/damselfly community composition and can impact conservation planning. Article link

Thomas Onuferko and colleages (Brock University) found that warmer climate leads to earlier nest initiation and lengthening of the flight season, but not to colony social organisation or queen-worker reproductive skew in a eusocial sweat bee. Article link

Gwylim Blackburn and colleagues at the University of British Columbia investigated the mating strategies of Habronattus americanus jumping spiders by documenting the movements, hunting activity, and social interactions of more than 100 individuals in their natural habitat. Males did not display directly to each other to compete for female mates. Instead, they traveled widely, eating nothing and displaying to every female they met. Females traveled significantly less than males and spent more time hunting. They also appeared picky when choosing mates, rejecting nearly every courting male that they encountered. These findings point to female mate choice as a potentially strong source of selection on male sexual displays. Article link

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An adult male Habronattus americanus jumping spider travels through beach habitat in British Columbia, Canada. The bright coloration on his face and legs is presented to females during elaborate courtship dances. Photo credit: Sean McCann.

Agriculture

With no natural enemies in North America, 4-5 generations per year, and early- and late-emerging phenotypes, local swede midge populations can overwhelm established management tactics and cause significant damage to broccoli, cauliflower, and other Brassica crops.  Laboratory experiments by Braden Evans, and his colleagues at the University of Guelph, showed that native (Ontario) strains of the entomopathogenic nematodes Heterorhabditis bacteriophoraSteinernema carpocapsae and Steinernema feltiae,and the entomopathogenic fungus Metarhizium brunneum all infected swede midge larvae, pupae and pre-pupal cocoons and all three nematode species successfully reproduced inside swede midge larval hosts.  Field experiments showed some suppression of adult emergence from the soil, suggesting that entomopathogens may hold some potential as a swede midge management tactic for conventional and organic producers. Article link

Adult swede midge, Contarinia nasturtii. Photo credit: D.K.B. Cheung

Adult swede midge, Contarinia nasturtii. Photo credit: D.K.B. Cheung

Haley Catton (UBC-O and AAFC Lethbridge) and colleagues found out that a controversial biocontrol weevil with low host specificity rarely attacks non-target plants in the field. Article link

Rassol Bahreini (University of Manitoba) found that differential Varroa mite removal of different honey bee stocks was possible under low temperature. Article link

Lygus lineolaris is the dominant mirid species in soy, navy, and pinto bean fields in Manitoba, reports Tharshi Nagalingam at the University of Manitoba. Article link

Ground beetles aren’t just important generalist predators – they eat weed seeds! A new review by Sharavari Kulkami (University of Alberta) and colleagues here: Article link

Physiology and Genetics

Genes encoding the peritrophic matrix of Mamestra configurata (Lepidoptera: Noctuidae) were expressed in the midgut of feeding larvae and the results were used to update a model on the lepidopteran peritriphic membrane. This work was conducted in part by Umut Toprak at the University of Saskatchewan. Article link

Christina Hodson, Phineas Hamilton and colleagues (University of Victoria) co-authored a review article by on the major consequences of uniparental transmission of mitochondria, and an unusual case of extreme sex ratio distortion in a booklouse. Article link

Two genes from the mitochondria genome have potential as genetic markers for examining the population genetics and phylogeography of black legged ticks reports Chantal Krakowetz and colleagues at the University of Saskatchewan. Article link

Harvir Hans and Asad Lone (McMaster Unviersity) found hormetic agents like metformin may derive significant trade-offs with life extension in crickets, whereas health and longevity benefits may be obtained with less cost by agents like aspirin that regulate geroprotective pathways. Article link

Work conducted by Litza Coello Alvarado and colleagues from the Sinclair lab at Western, found that increased tolerance of chilling is associated with improved maintenance of ion and water homeostasis in the cold for Gryllus crickets. Article ink


We are continuing to help publicize graduate student publications to the wider entomological community through our Research Roundup.  Find the first two editions here and here. If you published an article recently and would like it featured, e-mail us at entsoccan.students@gmail.com.  You can also send us photos and short descriptions of your research, to appear in a later edition of the research roundup.

For regular updates on new Canadian entomological research, you can join the ESC Students Facebook page or follow us on Twitter @esc_students

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Costly colouration in a forest moth: the tale of a ten-year research project

As part of the Canadian Entomology Research roundup (the first two posts can be found here and here), we will be sharing more detailed posts from the grad students involved in the published research.

Below is a post from Jessica Ethier, sharing her research experience that spanned an undergraduate and PhD degree.


I just published a paper in Entomologia Experimentalis et Applicata. From start to finish, the work only took a decade.

Ten years ago, in the summer of 2005, I had just finished my first year as an undergraduate student at Concordia University. I had no plans yet for what I would do after graduating; really, I was just glad I’d survived that first year. But across the country, unbeknownst to me, traps were being set, insects were being collected, and by the time I was starting my second year of university here in Montreal, a student at the University of Alberta was busy pulling the wings off a bunch of dead moths.

A horrific sight to innocent insect passers-by.

A horrific sight to innocent insect passers-by.

That student was Kevin Lake. He was doing his undergraduate research project on the effects of population density on wing size and colour in the Malacosoma disstria moth with Maya Evenden and Brad Jones. Fast-forward one year to the fall semester of 2006, and I had now transformed (one might say, metamorphosed) into a seasoned third year undergrad dabbling in research for the very first time. In Emma Despland’s lab, I had a freezer-ful of more dead moths just waiting to be de-winged and studied, and (thanks to Maya and Emma) the protocols Kevin used for wing removal and colour scoring. One thing led to another, and before I knew it, it was 2009 and I had just fast-tracked to a PhD from a Master’s for my research on colour polymorphism and wing melanization in the M. disstria moth.

One of the aims of my graduate research as a whole was to try and figure out why there was always so much individual variation in colour within the genetically-based phenotypes. Emma and I developed an experiment for spring of 2010 to see if limiting dietary protein in the larval stage limited the expression of colour in the adult moth. I even had my very own undergraduate student for the project, Michael Gasse, to rear the insects, process the wings, and collect the colour data. But it wasn’t all rainbows and puppies and pulling wings off dead moths. First we had to get the insects from somewhere.

As luck would have it, there was a forest tent caterpillar outbreak about an hour away from the city that year (for some reason, the landowners – maple syrup producers – were not nearly as gleeful about this infestation of their sugar maple forests as all the members of the Despland lab were). So off we trooped in the middle of February, tree clippers, binoculars, and plastic lunchboxes in hand, to go collect as many egg masses as we could get our mitts on.

You thought the lunchboxes were for lunches? Photo by Alison Loader

You thought the lunchboxes were for lunches? Photo by Alison Loader

Then it was back to school, to spend most of April, May, and June in the sub-basement dungeon lab, slaves to the needs of the exponentially-growing, insatiable eating and pooping machines that we called our experimental subjects.

First instar M. disstria colonies in 30mL hatching cups with artificial diet. Those cups are basically the little plastic shot glasses you see at dollar stores. By the time they reach the final instar, the caterpillars are typically longer than those cups are tall. Photo by Alison Loader.

First instar M. disstria colonies in 30mL hatching cups with artificial diet. Those cups are basically the little plastic shot glasses you see at dollar stores. By the time they reach the final instar, the caterpillars are typically longer than those cups are tall. Photo by Alison Loader.

We all survived another research season, and Mike moved on to wing-pulling and colour scoring a few hundred moths. Time flew by, as time will do, but in 2012 I finally finished and submitted my article on nitrogen availability and wing melanization in the Malacosoma disstria moth!

It was rejected.

Undeterred, I chose another journal and submitted again. And again. And again. After the fourth or fifth rejection, I stopped resubmitting. Not because I was giving up, but because I had to write my thesis and graduate. Once that little matter was taken care of, I went back to my pesky paper. Looking at it with fresh eyes, I realized that the two sections I had divided my paper into just did not complement each other, despite being based on the same experiment. Then I had an epiphany. One of the reasons for forest tent caterpillars to suffer nitrogen limitation in real life is high population density.

And the rest, as they say, is history.