Personne :
Samson-Robert, Olivier

En cours de chargement...
Photo de profil
Adresse électronique
Date de naissance
Projets de recherche
Structures organisationnelles
Nom de famille
Université Laval. Faculté des sciences de l'agriculture et de l'alimentation
Identifiant Canadiana

Résultats de recherche

Voici les éléments 1 - 8 sur 8
  • Publication
    Accès libre
    Commercial bumble bee (Bombus impatiens) hives under exclusion netting systems for apple pollination in orchards
    (Cambridge University Press, 2020-08-20) Normandeau Bonneau, Mélanie; Fournier, Valérie; Samson-Robert, Olivier; Chouinard, Gérald
    Exclusion netting systems are effective in various contexts and are increasingly used to control crop pests. However, factors affecting pollination management under nets are poorly known. The pollination effectiveness of commercial bumble bee hives of Bombus impatiens Cresson (Hymenoptera: Apidae) was studied for apple production under exclusion netting systems in a research orchard located in Quebec, Canada during 2016–2017. Sixteen single-row plots of apple trees (plot length: 18.5 m, cultivar GingerGold) were subjected to one of the following four treatments during bloom: (1) introduction of a bumble bee hive placed at the end of the row, under nets; (2) introduction of a bumble bee hive placed in the middle of the row, under nets; (3) negative control with no pollinators, under nets and (4) agronomic control with nearby bee hives (<50 m), without nets. Resulting post-harvest fruit quality (e.g., fruit weight, size, number and distribution of seeds) was evaluated, as well as correlations between bumble bee visitation rates and fruit quality parameters were evaluated. Results suggest that bumble bees provided adequate pollination under exclusion netting systems and that resulting fruit quality was equivalent to that of apple fruit conventionally pollinated by honey bees and wild bees community (bumble bees and other bees) in the orchard environment. Positioning bumble bee hives in the middle of the row provided better fruit load homogeneity in pollinated trees. Additional discussion on bumble bees as apple pollinators and on pollen distribution methods is also included.
  • Publication
    Accès libre
    Planting of neonicotinoid-coated corn raises honey bee mortality and sets back colony development
    (PeerJ Inc., 2017-08-14) Fournier, Valérie; Labrie, Geneviève; Samson-Robert, Olivier; Chagnon, Madeleine
    Worldwide occurrences of honey bee colony losses have raised concerns about bee health and the sustainability of pollination-dependent crops. While multiple causal factors have been identified, seed coating with insecticides of the neonicotinoid family has been the focus of much discussion and research. Nonetheless, few studies have investigated the impacts of these insecticides under field conditions or in commercial beekeeping operations. Given that corn-seed coating constitutes the largest single use of neonicotinoid, our study compared honey bee mortality from commercial apiaries located in two different agricultural settings, i.e. corn-dominated areas and corn-free environments, during the corn planting season. Data was collected in 2012 and 2013 from 26 bee yards. Dead honey bees from five hives in each apiary were counted and collected, and samples were analyzed using a multi-residue LC-MS/MS method. Long-term effects on colony development were simulated based on a honey bee population dynamic model. Mortality survey showed that colonies located in a corn-dominated area had daily mortality counts 3.51 times those of colonies from corn crop-free sites. Chemical analyses revealed that honey bees were exposed to various agricultural pesticides during the corn planting season, but were primarily subjected to neonicotinoid compounds (54% of analysed samples contained clothianidin, and 31% contained both clothianidin and thiamethoxam). Performance development simulations performed on hive populations’ show that increased mortality during the corn planting season sets back colony development and bears contributions to collapse risk but most of all, reduces the effectiveness and value of colonies for pollination services. Our results also have implications for the numerous large-scale and worldwide-cultivated crops that currently rely on pre-emptive use of neonicotinoid seed treatments.
  • Publication
    Accès libre
    Increased acetylcholinesterase expression in bumble bees during neonicotinoid-coated corn sowing
    (2015-07-30) Fournier, Valérie; Labrie, Geneviève; Samson-Robert, Olivier; Mercier, Pierre-Luc; Chagnon, Madeleine; Derome, Nicolas
    While honey bee exposure to systemic insecticides has received much attention, impacts on wild pollinators have not been as widely studied. Neonicotinoids have been shown to increase acetylcholinesterase (AChE) activity in honey bees at sublethal doses. High AChE levels may therefore act as a biomarker of exposure to neonicotinoids. This two-year study focused on establishing whether bumble bees living and foraging in agricultural areas using neonicotinoid crop protection show early biochemical signs of intoxication. Bumble bee colonies (Bombus impatiens) were placed in two different agricultural cropping areas: 1) control (≥3 km from fields planted with neonicotinoid-treated seeds) or 2) exposed (within 500 m of fields planted with neonicotinoid-treated seeds) and maintained for the duration of corn sowing. As determined by Real Time qPCR, AChE mRNA expression was initially significantly higher in bumble bees from exposed sites, then decreased throughout the planting season to reach a similar endpoint to that of bumble bees from control sites. These findings suggest that exposure to neonicotinoid seed coating particles during the planting season can alter bumble bee neuronal activity. To our knowledge, this is the first study to report in situ that bumble bees living in agricultural areas exhibit signs of neonicotinoid intoxication.
  • Publication
    Accès libre
    Supplying honey bees with waterers : a precautionary measure to reduce exposure to pesticides
    (Springer Berlin, 2021-01-05) McCune, Frédéric; Rondeau, Sabrina; Fournier, Valérie; Samson-Robert, Olivier
    Water is essential for honey bees (Apis mellifera L.), but contaminated sources of water in agricultural environments represent a risk of exposure to potentially harmful contaminants. Providing clean water to honey bees could be an efficient and cost-effective measure for beekeepers to reduce bee mortality associated with pesticides and improve the health of their colonies. The main goal of this study was to design a waterer prototype to fulfill the water requirements of honey bees and to evaluate the potential of this waterer in improving colonies’ health in agricultural settings, through mitigating the possible impact of an exposure to pesticides from puddle water. We tested the preference of honey bees regarding water composition and waterer prototypes, among which honey bees showed a strong preference for salted water and a poultry-type waterer. Our waterer models were quickly adopted and intensively used through the season in both the context of honey production in field crops and pollination services in cranberry crops. However, in neither context did the use of waterers reduce worker mortality nor increase overall colony weight. Our waterers provided bees with water containing fewer pesticides and were associated with reduced risks of drowning compared to natural sources of water. Our study suggests that the use of waterers fulfills an important requirement for honey bees and represents an interesting and convenient precautionary measure for beekeepers.
  • Publication
    Accès libre
    Chronic exposure to neonicotinoids reduces honey bee health near corn crops
    (American Association for the Advancement of Science, 2017-06-30) Tsvetkov, Nadejda; Fournier, Valérie; Samson-Robert, Olivier; Sood, Ramesh Kumar; Patel, Harshilkumar; Malena, D. A.; Gajiwala, P. H.; Maciukiewicz, Philip; Zayed, Amro
    Experiments linking neonicotinoids and declining bee health have been criticized for not simulating realistic exposure. Here we quantified the duration and magnitude of neonicotinoid exposure in Canada’s corn-growing regions and used these data to design realistic experiments to investigate the effect of such insecticides on honey bees. Colonies near corn were naturally exposed to neonicotinoids for up to 4 months—the majority of the honey bee’s active season. Realistic experiments showed that neonicotinoids increased worker mortality and were associated with declines in social immunity and increased queenlessness over time. We also discovered that the acute toxicity of neonicotinoids to honey bees doubles in the presence of a commonly encountered fungicide. Our work demonstrates that field-realistic exposure to neonicotinoids can reduce honey bee health in corn-growing regions.
  • Publication
    Accès libre
    Suivi d’abeilles domestiques et de pollinisateurs indigènes lors des semis de cultures traitées aux néonicotinoïdes
    (2014) Samson-Robert, Olivier; Fournier, Valérie; Labrie, Geneviève
    Les insecticides néonicotinoïdes, qui sont omniprésents en agriculture, sont un des principaux facteurs impliqués dans le déclin des populations d’abeilles domestiques et d’autres pollinisateurs sauvages. Dans cette étude, nous avons évalué les impacts des traitements de semences néonicotinoïdes sur le niveau de mortalité des abeilles domestiques, l’intoxication du bourdon fébrile (par le suivi d’un biomarqueur, acétylcholinestérase ou AChE) ainsi que sur la contamination de l’eau. Les résultats démontrent qu’à proximité des semis de maïs traités à l’insecticide le niveau de mortalité des colonies d’abeilles domestiques est quadruplé et le niveau d’AChE des bourdons est également plus élevé. Le projet a également permis de confirmer que les flaques d’eau à la surface des champs sont une nouvelle voie d’intoxication potentielle pour les abeilles. Ces résultats démontrent les nombreux impacts de l’utilisation massive des traitements de semences néonicotinoïdes et met en évidence le rôle essentiel qu'ils jouent dans l’actuel déclin des pollinisateurs.
  • Publication
    Accès libre
    Neonicotinoid-contaminated puddles of water represent a risk of intoxication for honey bees
    (Public Library of Science, 2014-12-01) Labrie, Geneviève; Samson-Robert, Olivier; Chagnon, Madeleine; Fournier, Valérie
    In recent years, populations of honey bees and other pollinators have been reported to be in decline worldwide. A number of stressors have been identified as potential contributing factors, including the extensive prophylactic use of neonicotinoid insecticides, which are highly toxic to bees, in agriculture. While multiple routes of exposure to these systemic insecticides have been documented for honey bees, contamination from puddle water has not been investigated. In this study, we used a multi-residue method based on LC-MS/MS to analyze samples of puddle water taken in the field during the planting of treated corn and one month later. If honey bees were to collect and drink water from these puddles, our results showed that they would be exposed to various agricultural pesticides. All water samples collected from corn fields were contaminated with at least one neonicotinoid compound, although most contained more than one systemic insecticide. Concentrations of neonicotinoids were higher in early spring, indicating that emission and drifting of contaminated dust during sowing raises contamination levels of puddles. Although the overall average acute risk of drinking water from puddles was relatively low, concentrations of neonicotinoids ranged from 0.01 to 63 µg/L and were sufficient to potentially elicit a wide array of sublethal effects in individuals and colony alike. Our results also suggest that risk assessment of honey bee water resources underestimates the foragers' exposure and consequently miscalculates the risk. In fact, our data shows that honey bees and native pollinators are facing unprecedented cumulative exposure to these insecticides from combined residues in pollen, nectar and water. These findings not only document the impact of this route of exposure for honey bees, they also have implications for the cultivation of a wide variety of crops for which the extensive use of neonicotinoids is currently promoted.
  • Publication
    Accès libre
    The impacts of two protein supplements on commercial honey bee (Apis mellifera L.) colonies
    (Taylor & Francis, 2019-08-02) Giovenazzo, Pierre; Lamontagne-Drolet, Marianne; Fournier, Valérie; Samson-Robert, Olivier
    Honey bees (Apis mellifera L.) are pollinators of major importance for crop production. In recent years, colony management has become more difficult due to multiple problems such as pesticide exposure, exotic parasites, pathogens and nutritional deficiencies. The latter has incited beekeepers to provide protein supplements to their colonies to make up for the lack of pollen resources in the environment. However, their efficiency varies depending on their composition and the surrounding landscape. In this field study, we provided two different protein supplements (Global Patties® and Ultra Bee®) to colonies with either limited or unlimited access to natural pollen to assess their impacts on various colony and individual bee parameters. We used 50 colonies distributed among three sites in the Montérégie area, in Quebec, Canada. We found that supplemented colonies limited in pollen collection were able to raise the same amount of brood than control colonies. Nurse bees in supplemented colonies also had a higher protein content compared to control bees. However, bees from supplemented colonies displayed shorter lifespan, which casts a doubt on the suitability of these products for honey bee nutrition. The supplement containing natural pollen, Global Patties®, was the most consumed and the most beneficial of the two for the colonies. Finally, colonies from the apiary surrounded by the highest proportion of cultivated land in a 5-km radius performed better toward the end of the season, which could be due to the presence of nutritionally interesting plants specific to the agricultural landscape at that time of the year.