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La crise des abeilles et la controverse entourant l’impact de l'usage des pesticides ont suscité un grand intérêt citoyen et médiatique au Québec de 2017 à 2020. Ce débat public a également révélé des problématiques au sein de certaines structures liées à la gouvernance des pesticides. Ces interrogations portent notamment sur les pratiques de gouvernance responsable et le rôle de l'industrie privée dans les décisions relatives à la gestion des pesticides. Plus précisément, ce travail de recherche développe une réflexion éthique autour de deux situations concrètes : la gouvernance au CÉROM et le double rôle des agronomes-vendeurs. On y évalue les situations de conflits d’intérêts potentiels et les pratiques de gouvernance qui peuvent influencer la gestion de l’usage des pesticides au Québec. Le premier cas examine la crise survenue au CÉROM, un centre de recherche principalement financé par des fonds publics, où en 2017, une enquête a révélé des pressions sur les chercheurs, les empêchant entre-autres de publier des travaux sur l’utilisation des néonicotinoïdes en grande culture. Cette recherche veut évaluer le conflit d’intérêts potentiel des administrateurs du centre, et l’impact de cette situation sur la gestion des pesticides. Elle examine également les implications d'autres enjeux connexes, tels que la diversité de l'expertise et la nécessité de suivis efficaces entre organisations. Le second cas aborde la dualité du rôle des agronomes-vendeurs, pris entre leur devoir de conseil impartial et leurs intérêts financiers dans la vente de pesticides aux agriculteurs. En 2018, un amendement réglementaire a exigé des agronomes une prescription qui vise à justifier la recommandation des néonicotinoïdes. Cette étude examine la présence de conflits d'intérêts chez les agronomes-vendeurs et l'influence de leur pouvoir de recommandation sur l’usage des pesticides. L'analyse se penche aussi sur l'approche en éthique organisationnelle adoptée par l'Ordre des Agronomes du Québ

"Le Québec est la principale province productrice de fraises au Canada. En 2018, la production de fraises était évaluée à un volume de plus de 15 millions de tonnes et représentait des revenus de 66 millions de dollars (Gouvernement du Québec, 2021). Malheureusement, dans les années à venir, les rendements de la culture pourraient être perturbés par les effets des changements climatiques. Parmi les nombreuses conséquences des changements climatiques, il pourrait y avoir une augmentation de la pression exercée sur les cultures de fraises par certains ravageurs ou agents pathogènes déjà présents au Québec, mais également une augmentation des introductions de nouveaux insectes ravageurs et de nouvelles maladies (Lehmann et al., 2020). Les changements climatiques ont une influence considérable sur ces insectes, car l’augmentation des températures favorise leur métabolisme et leur développement (Lehmann et al., 2020). Des températures plus élevées perturbent également les autres activités des insectes, comme l’alimentation, la reproduction, la croissance et les déplacements (Weintraub et al., 2019). Par conséquent, les hausses de température auront potentiellement pour effet d’accroître les densités de population d’insectes ravageurs dans les champs de fraises et augmenteront l’intensité des dommages ainsi que les pertes de rendements (Figure 1a). [...]"

The foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), and the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), are among the serious insect pests found in greenhouses. The efficacy of microbial control against these insects has been demonstrated and can be enhanced by the combination of different microbial agents. This study evaluated the efficacy of Bacillus pumilus Meyer and Gottheil PTB180 and Bacillus subtilis (Ehrenberg) Cohn PTB185, used alone and together, to control these two aphids both in the laboratory and in greenhouse on tomato, Solanum lycopersicum Linnaeus (Solanaceae), and cucumber, Cucumis sativus Linnaeus (Cucurbitaceae), plants. The results from the laboratory tests showed an increase in mortality induced by all biological treatments. In the greenhouse, all treatments induced mortality rates significantly higher than that of the control for A. solani. Similarly, all treatments performed better than the control against A. gossypii, significantly reducing its reproduction. Furthermore, we found no additive effects when mixing products nor negative interactions affecting survival for the bacteria investigated. These microorganisms therefore have potential for use in biological control., Les pucerons de la digitale, Aulacorthum solani (Kaltenbach) (Hemiptera : Aphididae), et du melon, Aphis gossypii Glover (Hemiptera : Aphididae), font partie des ravageurs les plus nuisibles en serres. L’efficacité de la lutte microbienne contre ces insectes a été démontrée et pourrait être améliorée par la combinaison de différents agents microbiens. Cette étude a évalué l’efficacité de Bacillus pumilus Meyer and Gottheil PTB180 et Bacillus subtilis (Ehrenberg) Cohn PTB185, utilisés seuls ou ensemble, pour lutter contre ces deux pucerons en laboratoire et en serre sur des plants de tomate, Solanum lycopersicum Linnaeus (Solanaceae), et de concombre, Cucumis sativus Linnaeus (Cucurbitaceae). En laboratoire, les résultats ont montré une augmentation de la mortalité induite par tous les traitements biologiques. En serres, pour A. solani, tous les traitements ont induit un taux de mortalité nettement supérieur au témoin. Tous les traitements ont aussi significativement réduit la reproduction de A. gossypii. De plus, nous ne montrons aucun effet additif lors du mélange des produits ni aucune interaction négative affectant la survie des bactéries. Ces microorganismes ont donc un potentiel intéressant pour la lutte biologique.

The foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), and the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), are among the serious insect pests found in greenhouses. The efficacy of microbial control against these insects has been demonstrated and can be enhanced by the combination of different microbial agents. This study evaluated the efficacy of Bacillus pumilus Meyer and Gottheil PTB180 and Bacillus subtilis (Ehrenberg) Cohn PTB185, used alone and together, to control these two aphids both in the laboratory and in greenhouse on tomato, Solanum lycopersicum Linnaeus (Solanaceae), and cucumber, Cucumis sativus Linnaeus (Cucurbitaceae), plants. The results from the laboratory tests showed an increase in mortality induced by all biological treatments. In the greenhouse, all treatments induced mortality rates significantly higher than that of the control for A. solani. Similarly, all treatments performed better than the control against A. gossypii, significantly reducing its reproduction. Furthermore, we found no additive effects when mixing products nor negative interactions affecting survival for the bacteria investigated. These microorganisms therefore have potential for use in biological control., Les pucerons de la digitale, Aulacorthum solani (Kaltenbach) (Hemiptera : Aphididae), et du melon, Aphis gossypii Glover (Hemiptera : Aphididae), font partie des ravageurs les plus nuisibles en serres. L’efficacité de la lutte microbienne contre ces insectes a été démontrée et pourrait être améliorée par la combinaison de différents agents microbiens. Cette étude a évalué l’efficacité de Bacillus pumilus Meyer and Gottheil PTB180 et Bacillus subtilis (Ehrenberg) Cohn PTB185, utilisés seuls ou ensemble, pour lutter contre ces deux pucerons en laboratoire et en serre sur des plants de tomate, Solanum lycopersicum Linnaeus (Solanaceae), et de concombre, Cucumis sativus Linnaeus (Cucurbitaceae). En laboratoire, les résultats ont montré une augmentation de la mortalité induite par tous les traitements biologiques. En serres, pour A. solani, tous les traitements ont induit un taux de mortalité nettement supérieur au témoin. Tous les traitements ont aussi significativement réduit la reproduction de A. gossypii. De plus, nous ne montrons aucun effet additif lors du mélange des produits ni aucune interaction négative affectant la survie des bactéries. Ces microorganismes ont donc un potentiel intéressant pour la lutte biologique.

The cyclamen mite (Phytonemus pallidus Banks; Acari: Tarsonemidae) has recently become a more important pest in Canadian strawberry (Fragaria × ananassa Duchesne ex Rozier; Rosaceae) production with the withdrawal of the pesticide endosulfan in 2016, yet its phenology under field conditions in Canada is poorly known. Moreover, while its biological control with predatory mites has shown potential, the effectiveness of this method has never been investigated under eastern Canadian field conditions. The objectives of this study were to 1) monitor populations of P. pallidus in strawberries for two consecutive years; and 2) evaluate the in-field potential of the predatory mite Neoseiulus cucumeris Oudemans (Acari: Phytoseiidae). Monitoring cyclamen mite populations in the field revealed new critical knowledge about its phenology in eastern Canada, such as activity until late November. The predator N. cucumeris was able to effectively suppress cyclamen mites the first year, but appeared to be too cold-sensitive to maintain adequate control toward the end of the season. Furthermore, the high rates of predator release required would most likely be cost prohibitive for commercial use. Control of the cyclamen mite in strawberries remains a complex issue that will require further research.

Bumblebees are essential, efficient pollinators of numerous crops, and scientists are increasingly concerned about their global decline. Although several potential causes have been put forward, the concurrent modification of landscape structure and pesticide use by agriculture are often pointed out as the main drivers of the decline. Yet, the mechanisms through which these factors cause species to decline remain elusive. Most field studies have been conducted at the individual level and the few studies that addressed higher levels of organization only covered narrow ecological conditions. We undertook a field experiment in spring 2016 to overcome these limitations by placing four commercial Bombus impatiens colonies in each of 20 sites located along a gradient of agricultural intensity in Southern Québec, Canada. We hypothesized that landscape habitat composition and configuration, as well as local floral resources, would affect colony development. We expected colonies surrounded by low intensity and/or flowering crops in heterogeneous landscapes to develop better and live longer, partly linked to more abundant and diversified food resources, than colonies embedded in landscapes dominated by high intensity crops. Colonies were weighed once a week, and workers were captured to assess pollen load diversity. Final colony weight, queen production and presence of depredators (Aphomia sociella, Lepidoptera: Pyralidae) were also recorded. Landscape habitat composition and configuration were characterized within 1 km of colonies. Local availability of floral resources was assessed within 100 m of colonies every two weeks. As predicted, colony weigh and longevity decreased with the proportion of intensive crops and increased with the amount of flowering crops, but queen production and the occurrence of A. sociella were not affected by landscape composition. Contrary to our prediction, local availability of floral resources also did not affect colonies. The pollen richness br

Commercial lowbush blueberry (Vaccinium angustifolium Ait.) and cranberry (Vaccinium macrocarpon Ait.) crops benefit from the presence of honey bee (Apis mellifera L.) for pollination. Unfortunately, beekeepers are observing negative impacts of pollination services on honey bee colonies. In this study, we investigated three beekeeping management strategies (MS) and measured their impact on honey bee colony health and development. Experimental groups (five colonies/MS) were: A) Control farmland honey producing MS (control MS); B) Blueberry pollination MS (blueberry MS); C) Cranberry pollination MS (cranberry MS) and D) Double pollination MS, blueberry followed by cranberry (double MS). Our goals were to 1) compare floral abundance and attractiveness of foraging areas to honey bees between apiaries using a Geographic Information System, and 2) compare honey bee colony health status and population development between MS during a complete beekeeping season. Our results show significantly lower floral abundance and honey bee attractiveness of foraging areas during cranberry pollination compared to the other environments. The blueberry pollination site seemed to significantly reduce brood population in the colonies who provided those services (blueberry MS and double MS). The cranberry pollination site seemed to significantly reduce colony weight gain (cranberry MS and double MS) and induce a significantly higher winter mortality rate (cranberry MS). We also measured significantly higher levels of Black queen cell virus and Sacbrood virus in the MS providing cranberry pollination (cranberry MS and double MS).

The growth of the commercial pollination industry raises important concerns regarding honey bee (Apis mellifera Linnaeus; Hymenoptera: Apidae) health and development. While providing such services, honey bees are often exposed to undiversified pollen sources that may contribute to nutritional deficiencies, notably in protein and amino acids. To understand how honey bees are affected during provision of pollination services, we compared honey bee colonies that pollinated lowbush blueberry (Vaccinium angustifolium Aiton; Ericaceae) and/or cranberry (Vaccinium macrocarpon Aiton; Ericaceae) crops (management strategies) with control colonies in a diversified farmland environment. We identified the floral species of pollen collected by honey bee colonies in those crops compared to pollen collected by control colonies. We also analysed the protein and essential amino acid content of collected pollen and bee bread and measured the nutritional impact of pollination services on honey bee colonies. We found that honey bees providing blueberry and/or cranberry pollination services are exposed to a less diversified pollen diet than colonies located in a farmland environment, especially in a cranberry field. There was a significantly lower proportion of crude protein content in collected and stored pollen during provision of blueberry pollination services, which led to a smaller brood population. Many nutritional deficiencies were measured with regards to essential amino acids.

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 impatiensCresson (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: 18.5m, 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 (less than 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. 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

The ectoparasitic mite Varroa destructor Anderson & Trueman is a major pest of the honey bee Apis mellifera L. (Hymenoptera: Apidae) and its control is one of the most important challenges that beekeepers have to face. In this study, we investigated the use of the predatory mite Stratiolaelaps scimitus (Womersley) for the biological control of varroa mites in Eastern Canada, as part of an integrated pest management strategy. Our study aimed to evaluate the effectiveness of S. scimitus in controlling varroa populations in early and late fall in comparison with untreated colonies and two currently used organic treatments: Thymovar and oxalic acid. Performing weekly mite drop monitoring, we first compared the effectiveness of two introduction rates of S. scimitus (≈6,250 or 12,500 mites/colony) during a fall treatment (September) and, as we detected no differences of effectiveness between these two treatment types, we used the dosage currently recommended by biocontrol suppliers (≈6,250 mites) in a complementary treatment test (November). Results showed that S. scimitus did not succeed in controlling varroa populations in honey bee colonies when introduced either in early or in late fall according to current suppliers’ recommended rates and application method. On the other hand, our results demonstrated that Thymovar and oxalic acid remain effective options for controlling varroa mite populations during fall in Quebec, Canada.

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.

The conservation of bee populations for pollination in agricultural landscapes has attracted a lot of recent research interest, especially for crop industries undergoing expansion to meet increased production demands. In Canada, much growth has been occurring with commercial cranberry production, a field crop which is largely dependent on bee pollination. Wild bee pollinators could be negatively impacted by losses of natural habitat surrounding cranberry fields to accommodate increased production, but growers have little insight on how to manage their lands to maximize the presence of wild bees. Here, we described a 2-yr study where bee diversity and species composition were investigated to better understand the dynamic between natural habitat and cranberry fields. Bees were sampled using pan-traps and hand netting both within cranberry fields and in one of the three adjacent natural habitat types once a week during the crop flowering period. We found that bee community composition among cranberry fields did not differ based on the respective adjacent habitat type, but fields bordered by meadows were marginally less diverse than fields bordered by forest. As one would expect, field and natural habitat communities differed in terms of species composition and species richness. There was no evidence that one type of natural habitat was more favorable for the bees than another. Future agrobiodiversity studies should simultaneously examine bee diversity comprised in both crop fields and adjacent natural environments to better understand the species dynamics essential to the preservation of pollination services.

Access to a rich diversity of flowering plants is very important for the development of honey bee colonies introduced in crops for pollination. The aim of this observational study was to determine the impact of surrounding pollen diversity on the health of honey bee colonies introduced in lowbush blueberries (Vaccinium angustifolium) in June and cranberries (V. macrocarpon) in July. The results suggest that monocultures of lowbush blueberries are not suitable for optimal brood rearing. In the blueberry environments we studied, the dominant pollen collected by honey bees were Alnus spp. and Taraxacum officinale, which are deficient in some essential amino acids. Significant reduction of brood rearing during bees’ stay in blueberry monocultures in June may therefore be explained by nutritional deficiencies. In July, the polliniferous flora in the vicinity of cranberry monocultures was poorer, but of better nutritional quality. Pollen analysis allowed the identification of Brassicaceae, Trifolium spp. and V. macrocarpon as the three dominant taxa collected by bees during this period. The complete lists of plant taxa foraged by honey bees for pollen during the pollination of lowbush blueberries and cranberries are provided., L’accessibilité à une flore diversifiée est très importante pour le développement des colonies d’abeilles domestiques introduites dans une culture pour le service de pollinisation. Notre étude observationnelle visait à déterminer l’impact de la diversité florale environnante sur la santé des colonies d’abeilles introduites dans les cultures de bleuets nains (Vaccinium augustifolium) en juin et de canneberges (V. macrocarpon) en juillet au Québec (Canada). Les résultats suggèrent que les monocultures de bleuets nains n’offrent pas une flore adéquate pour l’élevage optimal du couvain. Les plantes qui furent le plus butinées pour le pollen dans cet environnement, Alnus spp. et Taraxacum officinale, sont déficientes en certains acides animés essentiels à l’abeille. La diminution significative de la surface de couvain dans les monocultures de bleuets en juin pourrait donc être expliquée par des carences alimentaires. Dans l’environnement de la canneberge, les grains de pollen récoltés par les abeilles furent moins taxonomiquement variés que dans l’environnement du bleuet mais étaient de meilleures qualités nutritionnelles. Les taxons dominants récoltés par les abeilles furent les Brassicacées, Trifolium spp. et V. macrocarpon. Les listes complètes des taxons des plantes butinées pour le pollen pendant la pollinisation du bleuet nain et de la canneberge sont fournies.