• An analysis of aquatic invasive species management in the Niagara region of Ontario, Canada: establishment of a database to improve knowledge sharing

      Brown, Lyn; Vasseur, Liette (Regional Euro-Asian Biological Invasions Centre (REABIC), 2020)
      The UN Convention on Biological Diversity has declared invasive species a global threat and requested increased data sharing to prevent further impact. Existing worldwide and local databases mainly focus on distribution, abundance, identification, and impacts of invasive species, but very few record management activities. In the Niagara region of Ontario, Canada, no database focuses specifically on invasive species management. The goal of this study was to document current aquatic and riparian invasive species management activities in the Niagara region and develop a database that would become a tool to facilitate collaboration at the regional level. The objectives were to (1) inventory current invasive species detection and control activities in the Niagara region; (2) examine perceived efficacy of control techniques; and (3) develop a database integrated with a GIS mapping component. Seventy-one organizations involved in riparian/aquatic invasive species management in the Niagara region were contacted and 16 in-depth interviews were conducted. In 2017–2018, 35 separate control efforts were reported, involving 10 riparian invasive species and two aquatic invasive species, mostly concentrated along the Niagara River. Collaboration efforts were minimal, occurring for only six specific projects. Recommendations include develop a regional invasive species plan; increase control efforts along the Welland Canal and Lake Erie shoreline; adopt a wider variety of control techniques; and increase collaboration, information-sharing and resource-sharing among organizations. Overall, the newly developed database provides a baseline for the current state of aquatic and riparian invasive species management activities in the region. It can also help bridge the gap between invasive species science and decision-making by forming a tool to identify resource-sharing opportunities, management efficacy, priority areas, areas of improvement, and future resource needs. The database will enrich the global invasive species information network by providing Niagara-specific information. The database could also act as a model for tracking management activities of other invasive species and in other regions of North America.
    • Are Yellow Sticky Cards and Light Traps Effective on Tea Green Leafhoppers and Their Predators in Chinese Tea Plantations?

      Shi, Longqing; He, Haifang; Yang, Guang; Huang, Huoshui; Vasseur, Liette; You, Min-Sheng (MDPI, 2020)
      In Chinese tea plantations, yellow sticky cards and light traps are increasingly used to control insect pests, especially the tea green leafhopper . In this study, a 16-week open-field experiment with daily weather monitoring was designed to test the responses of tea green leafhopper, parasitoids and spiders to yellow sticky cards and three light traps with different wavelengths (covered with sticky cards). An exclosure experiment was also designed to further test the influence of the three light systems (without sticky card) on the same species. The results showed that all three light emitting diode (LED) light traps (white, green and yellow) and yellow sticky cards attracted many more male adults than females during the course of the open field experiment, with less than 25% of trapped adults being females. Parasitoids and spiders were also attracted by these systems. Weather variables, especially rainfall, influenced the trapping efficiency. In the exclosure experiment, the population of leafhoppers in the yellow sticky card treatment did not decline significantly, but the number of spiders significantly decreased. The green and white light treatments without sticky cards showed a significant control of and no obvious harm to spiders. These results suggest that yellow sticky cards and light traps have limited capacity to control tea green leafhoppers. However, light, especially green light, may be a promising population control measure for tea green leafhoppers, not as killing agents in the traps, but rather as a behavioral control system.
    • Climatic and Environmental Changes Affecting Communities in Atlantic Canada

      Vasseur, Liette; Thornbush, Mary; Plante, Steve (MDPI, 2017-07-27)
      Small rural coastal communities located in Atlantic Canada are vulnerable to the effects of climate and environmental changes. Major storms have impounded the coastline, causing much physical damage and affecting the socio-economics of these communities that are composed of an aging population. The current study relays findings based on interviews completed in 2011–2012, following the 2010 winter storms in Atlantic Canada. It portrays the physical and social–ecological impacts affecting 10 coastal communities located in the provinces of Québec, New Brunswick, and Prince Edward Island. Semi-structured interviews held in these provinces are the basis for the contributions of this research. The findings reveal physical changes related to coastal erosion from high-wave impacts and storm surge causing flooding of the coastal zone. Also considered are strategies preferred and actually implemented by residents, such as building of protection walls, although undesirable. Due to funding constraints, however, many of these large-scale flood protection projects are not possible without governmental support. Instead, it is suggested that development be controlled and some respondents in this study upheld that relocation be used to alleviate the situation. Finally, more work is required to improve emergency planning. Better concerted short- and long-term responses need to be coordinated by local authorities and higher up in the government in order to ensure the sustainability of these coastal communities.
    • Connecting Memories with Nature: Opportunities for Residents of Long-Term Care Facilities in Mid-Sized Cities

      Vasseur, Liette; Fullerton, Christopher; Jacklin, Marcie; Pickering, Kerrie (Evergreen, 2018)
      Canada, like other Western countries, is facing the challenge of providing care for an increasingly large elderly population. Indeed data suggest that the Canadian elderly population will double by 2036 (Statistics Canada 2006). In Ontario, this means that the population of people over 65 years old may increase from 1.8 million in 2009 (i.e., 13.7% of the population) to 4.2 million or 23.4% by 2036 (Ontario 2009). Society encourages elderly people to stay in their homes for as long as they can, but this often becomes impossible unless constant personal care can be provided by a parent or personal caretaker. The current economic and time constraints facing children of elderly people make it difficult for them to be able to consider full-time care of an elderly parent. In most cases, and especially for individuals suffering from dementia, placement in a long-term care (LTC) facility is often the only solution. While residents in some of these facilities may have gradual levels of independencies, in many of them residents have limited mobility. Residents in LTC facilities have a decreased sense of well-being compared to their counterparts living in other types of housing, such as their own homes or retirement facilities (Cummings 2002).
    • CRISPR/Cas9-Mediated Vitellogenin Receptor Knockout Leads to Functional Deficiency in the Reproductive Development of Plutella xylostella

      Peng, Lu; Wang, Qing; Zou, Ming-Min; Qin, Yu-Dong; Vasseur, Liette (Frontiers Media, 2020)
      The vitellogenin receptor (VgR) belongs to the low-density lipoprotein receptor (LDLR) gene superfamily and plays an indispensable role in Vg transport, yolk deposition, and oocyte development. For this reason, it has become a promising target for pest control. The involvement of VgR in Vg transport and reproductive functions remains unclear in diamondback moths, Plutella xylostella (L.), a destructive pest of cruciferous crops. Here, we cloned and identified the complete cDNA sequence of P. xylostella VgR, which encoded 1805 amino acid residues and contained four conserved domains of LDLR superfamily. PxVgR was mainly expressed in female adults, more specifically in the ovary. PxVgR protein also showed the similar expression profile with the PxVgR transcript. CRISPR/Cas9-mediated PxVgR knockout created a homozygous mutant of P. xylostella with 5-bp-nucleotide deletion in the PxVgR. The expression deficiency of PxVgR protein was detected in the ovaries and eggs of mutant individuals. Vg protein was still detected in the eggs of the mutant individuals, but with a decreased expression level. However, PxVg transcripts were not significantly affected by the PxVgR knockout. Knockout of PxVgR resulted in shorter ovarioles of newly emerged females. No significant difference was detected between wild and mutant individuals in terms of the number of eggs laid in the first 3 days after mating. The loss of PxVgR gene resulted in smaller and whiter eggs and lower egg hatching rate. This study represents the first report on the functions of VgR in Vg transport, ovary development, oviposition, and embryonic development of P. xylostella using CRISPR/Cas9 technology. This study lays the foundation for understanding molecular mechanisms of P. xylostella reproduction, and for making use of VgR as a potential genetic-based molecular target for better control of the P. xylostella.
    • Differential Profiles of Gut Microbiota and Metabolites Associated with Host Shift of Plutella xylostella

      Yang, Fei-Ying; Saqib, Hafiz Sohaib Ahmed; Chen, Jun-Hui; Ruan, Qian-Qian; Vasseur, Liette; He, Wei-Yi; You, Min-Sheng (MDPI, 2020)
      Evolutionary and ecological forces are important factors that shape gut microbial profiles in hosts, which can help insects adapt to different environments through modulating their metabolites. However, little is known about how gut microbes and metabolites are altered when lepidopteran pest species switch hosts. In the present study, using 16S-rDNA sequencing and mass spectrometry-based metabolomics, we analyzed the gut microbiota and metabolites of three populations of : one feeding on radish (PxR) and two feeding on peas (PxP; with PxP-1 and PxP-17 being the first and 17th generations after host shift from radish to peas, respectively). We found that the diversity of gut microbes in PxP-17 was significantly lower than those in PxR and PxP-1, which indicates a distinct change in gut microbiota after host shift. Kyoto Encyclopedia of Genes and Genomes analysis revealed that the functions of energy metabolism, signal transduction, and xenobiotics biodegradation and metabolism were increased in PxP-17, suggesting their potential roles in host adaptation. Metabolic profiling showed a significant difference in the abundance of gut metabolites between PxR and PxP-17, and significant correlations of gut bacteria with gut metabolites. These findings shed light on the interaction among plants, herbivores, and symbionts, and advance our understanding of host adaptation associated with gut bacteria and metabolic activities
    • Ecological Risk Assessment of Soil Heavy Metals and Pesticide Residues in Tea Plantations

      He, Haifang; Shi, Longqing; Yang, Guang; You, Minsheng; Vasseur, Liette (MDPI, 2020)
      Tea plantations have used many synthetic chemicals to ensure performance and control of pests. This has led to increased contamination of soils and reduced tea growth. We assessed the levels of heavy metals, including Cd, Cr, Pb, Cu, Ni, Zn, Hg, As, and pesticide residues, such as HCHs, biphenyl chrysanthemum ester, methamidophos, imidacloprid, permethrin, in the soil of tea plantations of Taiwan, Tibet, Guangdong, and Fujian. The Potential Ecological Risk Index and the Nemerow comprehensive pollution index were used to analyze the data. The results showed that risk indices in Tibet, Guangdong and Fuzhou were considered as moderate ecological harm level. Ecological risk assessment index of Anxi organic and Anxi conventional tea gardens suggested a "low" risk level. The Nemerow comprehensive pollution indices for soil pesticide residues in the tea plantations of Taiwan, Tibet, Anxi organic and Anxi conventional were considered mild. Guangdong and Fuzhou had values suggesting "slight pollution” levels. According to National Soil Environmental Quality Standard (GB15618-1995), soil in tea plantations in Taiwan, Tibet, and Anxi conventional matched the national first grade of soil quality and those from Guangdong, Fuzhou, and Anxi organic tea garden matched the national second grade.
    • Enjeux d’éducation aux changements climatiques auprès des communautés

      Vasseur, Liette (2020)
      Bien que les acteurs locaux soient les premiers à subir les conséquences des changements climatiques, il ne leur est pas toujours facile de comprendre les phénomènes en cause et de faire des choix d’actions pertinents. En se basant sur des études menées au Canada et en Équateur, cet article montre à quel point il est important de connaître les besoins de formation des différentes communautés et d’adopter des approches et stratégies éducatives appropriées. Certaines approches permettent non seulement d’informer, mais aussi de favoriser l’apprentissage social, d’éclairer la prise de décision et de stimuler l’engagement. En particulier, nous proposons une approche d’adaptation aux changements climatiques basée sur les écosystèmes et la gouvernance écosystémique. Les stratégies éducatives que nous avons associées à une telle approche incluent la vulgarisation des connaissances scientifiques, la participation active des citoyens permettant le partage des savoirs locaux et le développement d’outil de visualisation sur le web.
    • From the Book Review Editor of the Special Issue on Climate Change

      Vasseur, Liette (Nighthawks Open Institutional Repository, 2021)
      Climate change is affecting the lives of many communities and how to prepare for these changes is not always easy to define. To enhance community engagement in both mitigation and adaptation to climate change, there is a need to better assess how the complexity of climate change is affecting not only humans but the ecosystem where they live and the interactions among nature and people. This means also understanding how politics, policies, and other issues may help (or not) to improve engagement of communities in moving from discourse to action.
    • Host Plant-Derived miRNAs Potentially Modulate the Development of a Cosmopolitan Insect Pest, Plutella xylostella

      Zhang, Ling-Ling; JIng, Xiao-Dong; Chen, Wei; Wang, Yue; Lin, Jun-Han; Zheng, Ling; Dong, Yu-Hong; Zhou, Li; Li, Fei-Fei; Yang, Fei-Ying; et al. (MDPI, 2019)
      Plant microRNAs (miRNAs) have recently been reported to be involved in the cross-kingdom regulation of specific cellular and physiological processes in animals. However, little of this phenomenon is known for the communication between host plant and insect herbivore. In this study, the plant-derived miRNAs in the hemolymph of a cruciferous specialist were identified by small RNAs sequencing. A total of 39 miRNAs with typical characteristics of plant miRNAs were detected, of which 24 had read counts ≥ 2 in each library. Three plant-derived miRNAs with the highest read counts were validated, and all of them were predicted to target the hemocyanin domains-containing genes of . The luciferase assays in the S2 cell demonstrated that miR159a and novel-7703-5p could target and respectively, possibly in an incomplete complementary pairing mode. We further found that treatment with agomir-7703-5p significantly influenced the pupal development and egg-hatching rate when reared on the artificial...
    • How Ecosystem-Based Adaptation to Climate Change Can Help Coastal Communities through a Participatory Approach

      Vasseur, Liette (MDPI, 2021)
      Coastal rural communities worldwide face many challenges not only related to climate change but also extreme events, environmental degradation, population growth or aging, and conflict usage of the ecosystem. Historically, the economies of coastal communities have been based on the exploitation of natural resources, thus shaping its socioeconomic development. This has led to some limitations in the way these communities can now adapt to climate change. In Canada, coastal communities are increasingly dealing with climate change consequences. Sea level rise, coastal erosion, and increasing frequency in storm surges threaten the fragility of both natural and human systems. Various approaches have been used to try to reduce the vulnerability and improve adaptive capacity of communities. One approach, promoted by many organizations including the United Nations, is ecosystem-based adaptation. This approach is part of the series of nature-based solutions that help social–ecological systems become more resilient; by promoting biodiversity conservation and ecosystem services, this approach also relates to principles of community engagement and supports adaptive governance and social inclusion. This paper describes and analyzes these principles and considers strategies for ensuring community engagement. Combining ecosystem-based adaptation with a strong community engagement can enhance the long-term sustainability of the social-ecological system.
    • Identification of Halloween Genes and RNA Interference-Mediated Functional Characterization of a Halloween Gene shadow in Plutella xylostella

      Peng, Lu; Wang, Lei; Zou, Ming-Min; Vasseur, Liette; Chu, Li-Na; Qin, Yu-Dong; Zhai, Yi-Long (Frontiers Media, 2019)
      Ecdysteroids play an essential role in controlling insect development and reproduction. Their pathway is regulated by a group of enzymes called Halloween gene proteins. The relationship between the Halloween genes and ecdysteroid synthesis has yet to be clearly understood in diamondback moth, Plutella xylostella (L.), a worldwide Lepidoptera pest attacking cruciferous crops and wild plants. In this study, complete sequences for six Halloween genes, neverland ( nvd ), shroud ( sro ), spook ( spo ), phantom ( phm ), disembodied ( dib ), shadow ( sad ), and shade ( shd ), were identified. Phylogenetic analysis revealed a strong conservation in insects, including Halloween genes of P. xylostella that was clustered with all other Lepidoptera species. Three Halloween genes, dib , sad , and shd were highly expressed in the adult stage, while nvd and spo were highly expressed in the egg and pupal stages, respectively. Five Halloween genes were highly expressed specifically in the prothorax, which is the major site of ecdysone production. However, shd was expressed predominantly in the fat body to convert ecdysone into 20-hydroxyecdysone. RNAi-based knockdown of sad , which is involved in the last step of ecdysone biosynthesis, significantly reduced the 20E titer and resulted in a longer developmental duration and lower pupation of fourth-instar larvae, as well as caused shorter ovarioles and fewer fully developed eggs of P. xylostella . Furthermore, after the knockdown of sad , the expression levels of Vg and VgR genes were significantly decreased by 77.1 and 53.0%. Meanwhile, the number of eggs laid after 3 days was significantly reduced in sad knockdown females. These results suggest that Halloween genes may play a critical role in the biosynthesis of ecdysteroids and be involved in the development and reproduction of P. xylostella . Our work provides a solid basis for understanding the functional importance of these genes, which will help to screening potential genes for pest management of P. xylostella.
    • Impacts of Smooth Pigweed (Amaranthus hybridus) on Cover Crops in Southern Ontario

      VanVolkenburg, Heather; Guinel, Frederique C.; Vasseur, Liette (MDPI, 2020-04-08)
      Amaranthushybridus is anoxious weed in Ontario, with demonstrated allelopathic properties that can lead to decreased agricultural production. We tested the germination and growth of five cover crop species exposed to A. hybridus extracts, and to dried or fresh materials in soil. A germination index was calculated, and the dry weight of plant organs were measured to quantify responses to treatments. All species had reduced germination (≤29%) in 100% extract. Trifolium pratense had significant root weight reductions in extract (52%) and dried (72%) treatments, whereas shoot weight only decreased (48%) in dried treatment. Medicagosativa shoot weight decreased (52%) in 20g fresh treatment, while root weight decreased (62%) in dried treatment. Shoot weight of Raphanus sativus increased (32%) at mid-extract concentrations, while root weight increased (33%) only with dried treatment; however, both its shoot and root weight decreased (>40%) in fresh treatment. Only the shoot weight of Loliummultiflorum increased (41% in 75% extract and 55% in dried treatment). Both Cichorium intybus shoot and root weights decreased (~50%) in fresh treatment. Crop responses to A. hybridus are complex, and material and species-dependant. Further testing in the field may provide a more comprehensive understanding of how to improve the management of A. hybridus.
    • Is It Time to Shift Our Environmental Thinking? A Perspective on Barriers and Opportunities to Change

      Daigle, Christine; Vasseur, Liette (MDPI, 2019)
      In 2015, the United Nations General Assembly unanimously adopted the 2030 Agenda for Sustainable Development and Sustainable Development Goals. In 2019, the release of the global assessment report of the United Nations’ Intergovernmental Platform on Biodiversity and Ecosystem Services unfortunately demonstrated that our planet may be in more trouble than expected. The main drivers have been identified for many years and relate to human activities such as over-exploitation of natural resources leading to land degradation, deforestation, ocean and atmospheric pollution, and climate change. Despite international agreements and conventions, we are gradually reaching the planet’s boundaries. In this commentary, we present an analysis of the current worldview, discuss the humanist roots of this view, and the barriers to be able to move forward with the transformative changes that are needed for sustainability. We suggest that for these transformative changes to happen, there is a need to reconnect humans with nature, and we propose that some solutions could be devised in areas like education and social media. Changing our mindsets and worldviews are the most urgent courses of action we must undertake to avoid the inevitable
    • Mechanism and consequences for avoidance of superparasitism in the solitary parasitoid Cotesia vestalis

      Chen, Wen-Bin; Vasseur, Liette; Zhang, Shuai-Qi; Zhang, Han-Fang; Mao, Jun; Liu, Tian-Sheng; Zhou, Xian-Yong; Wang, Xin; Zhang, Jing; You, Min-Sheng; et al. (Nature Research, 2020)
      A parasitoid's decision to reject or accept a potential host is fundamental to its fitness. Superparasitism, in which more than one egg of a given parasitoid species can deposit in a single host, is usually considered sub-optimal in systems where the host is able to support the development of only a single parasitoid. It follows that selection pressure may drive the capacity for parasitoids to recognize parasitized hosts, especially if there is a fitness cost of superparasitism. Here, we used microsatellite studies of two distinct populations of Cotesia vestalis to demonstrate that an egg laid into a diamondback moth (Plutella xylostella) larva that was parasitized by a conspecific parasitoid 10 min, 2 or 6 h previously was as likely to develop and emerge successfully as was the first-laid egg. Consistent with this, a naive parasitoid encountering its first host was equally likely to accept a healthy larva as one parasitized 10 min prior, though handling time of parasitized hosts was extended. For second and third host encounters, parasitized hosts were less readily accepted than healthy larvae. If 12 h elapsed between parasitism events, the second-laid egg was much less likely to develop. Discrimination between parasitized and healthy hosts was evident when females were allowed physical contact with hosts, and healthy hosts were rendered less acceptable by manual injection of parasitoid venom into their hemolymph. Collectively, these results show a limited capacity to discriminate parasitized from healthy larvae despite a viability cost associated with failing to avoid superparasitism.
    • Molecular Characterization and the Function of Argonaute3 in RNAi Pathway of Plutella xylostella

      Hameed, Muhammad Salman; Wang, Zhengbing; Vasseur, Liette; Yang, Guang (MDPI, 2018-04-01)
      Argonaute (Ago) protein family plays a key role in the RNA interference (RNAi) process in different insects including Lepidopteran. However, the role of Ago proteins in the RNAi pathway of Plutella xylostella is still unknown. We cloned an Argonaute3 gene in P. xylostella ( PxAgo3 ) with the complete coding sequence of 2832 bp. The encoded protein had 935 amino acids with an expected molecular weight of 108.9 kDa and an isoelectric point of 9.29. It contained a PAZ (PIWI/Argonaute/Zwile) domain and PIWI (P-element-induced whimpy testes) domain. PxAgo3 was classified into the Piwi subfamily of Ago proteins with a high similarity of 93.0% with Bombyx mori Ago3 (BmAgo3). The suppression of PxAgo3 by dsPxAgo3 was observed 3 h after treatment and was maintained until 24 h. Knockdown of PxAgo3 decreased the suppression level of PxActin by dsPxActin in P. xylostella cells, while overexpression of PxAgo3 increased the RNAi efficiency. Our results suggest that PxAgo3 play a key role in the double stranded RNA (dsRNA)-regulated RNAi pathway in P. xylostella .
    • New pathways for teaching and learning: the posthumanist approach

      Blaikie, Fiona; Daigle, Christine; Vasseur, Liette (Canadian Commission for UNESCO, 2020)
      “How does one “posthuman” teach another? Applying a posthumanist approach to education involves rethinking pedagogy, knowledge production and dissemination. If there is a need to understand the world differently, we must “defamiliarize [our] mental habits” (Braidotti 2019, 77) by moving away from a humanist worldview. This worldview has not only shaped our thoughts, but also our institutions. Universities and education systems are structured around binaried teacher-learner relationships, as well as seeing disciplines and school subjects as discrete entitites with their own objects and methods of study and practices. What changes must we bring about so that we can imagine and understand the world and ourselves in new ways? A posthuman approach can change the way we value ourselves, other species, the planet, and beyond. It requires thinking about the system as a whole instead of each agent as a perfect independent entity; it requires valuing all agents and their relationality.”
    • De nouvelles voies pour l’enseignement et l’apprentissage : l’approche posthumaniste

      Blaikie, Fiona; Daigle, Christine; Vasseur, Liette (Commission canadienne pour l’UNESCO, 2020)
      La pédagogie, c’est-à-dire la méthode et la pratique de l’enseignement, est relationnelle et complexe, et elle dépend des conditions du moment. Si l’enseignement à distance en ligne peut sembler judicieux, le fait d’y recourir de façon systématique pour remplacer l’enseignement indique une vision étroite de l’éducation que l’on considère, à tort, comme étant une simple transmission de contenu. Selon la logique à l’œuvre dans la crise actuelle, puisque le contenu ne peut être diffusé en classe, les enseignants et leurs élèves peuvent rapidement adopter d’autres outils technologiques pour assurer l’enseignement et l’apprentissage à distance. Cette approche exige des élèves qu’ils apprennent dans une sorte de vide, et leurs parents, tuteurs ou gardiens doivent assumer le rôle des éducateurs, souvent sans avoir accès au matériel nécessaire ni à l’Internet, ou sans avoir la capacité, le temps et l’intérêt nécessaires pour faciliter l’apprentissage (Cerna, 2020; ONU, 2020).
    • Rewilding for human health

      Andrade, Angela; Zambrana-Torrelio, Carlos; Vasseur, Liette; Nelson, Cara; Carver, Steve (The Resurgence Trust, 2020)
      Exploring the connections between zoonotic diseases, human health and well-being, ecosystem degradation and biodiversity loss.
    • Strengthening our connection to nature and building citizens of the Earth

      Vasseur, Liette; Daigle, Christine (UNESCO, 2020-01-28)
      The authors elaborate on the dangers of rampant consumerism and attempt to explain why most humans are disconnected from the realities of our depleting planet and are not taking action to instigate change to ensure a more sustainable future. They argue that education for sustainable development will play a key role in transforming citizens of this Earth to assume fully their roles as environmental stewards.