About the lab
We are an entomology lab. We work on agricultural and ecological questions on beneficial arthropods (pollinators, predatory mites, etc.) and pests. Our research topics include the potential of arthropods as biological control agent for crop protection, the biodiversity of wild bees and other pollinators in various crops and settings and the health of the honey bee related to various environmental stress.
You can find our website here: https://valeriefournierlab.weebly.com/
You can find our website here: https://valeriefournierlab.weebly.com/
Featured projects (1)
To determine the impact of urban beekeeping competition on wild bees in Montreal. To determine if floral resources can influence these competitive interactions. To determine the impact of urban heat islands on wild bee communities.
Featured research (7)
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.
Cannabis (Cannabis sativa L. [Rosales: Cannabaceae]) is a newly legalized crop and requires deeper insights on its pest communities. In this preliminary study, we identified a thrips species affecting indoor grown cannabis in Canada and tested its impact on plant yield. We used three levels of initial infestation (zero, one, and five thrips) on individual plants grown in two growing mediums: conventional substrate or substrate containing the biostimulant Bacillus pumilus Meyer and Gottheil [Bacillales: Bacillaceae]. We found that the onion thrips (Thrips tabaci (Lindeman) [Thysanoptera: Thripidae]) is proliferating in indoor grown cannabis. Furthermore, our results showed that fresh yields were higher for the plants that initially received zero thrips compared to those that initially received five thrips. Moreover, the biostimulant only marginally helped reduce the impact of thrips. We highlight the importance for growers to carefully monitor thrips infestations in indoor grown cannabis. Finally, we emphasize the need for more research related to the impact of pests on cannabis yields and safe means of pest control for this strictly regulated crop.
Abstract Bumble bees 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 weight 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 brought back to colonies decreased with the proportion of flowering crops and varied according to the proportion of intensive crops interacting with local floral resources. Our work contributes to generalize the more restrictive conclusion of local‐scale, crop‐specific studies that intensive crop farming undermines bumble bee colony development and that it may thus play a role in the large‐scale population decline of these insects.
Bumble bee communities are strongly disrupted worldwide through the population decline of many species; a phenomenon that has been generally attributed to landscape modification, pesticide use, pathogens, and climate change. The mechanisms by which these causes act on bumble bee colonies are, however, likely to be complex and to involve many levels of organization spanning from the community down to the least understood individual level. Here, we assessed how the morphology, weight and foraging behavior of individual workers are affected by their surrounding landscape. We hypothesized that colonies established in landscapes showing high cover of intensive crops and low cover of flowering crops, as well as low amounts of local floral resources, would produce smaller workers, which would perform fewer foraging trips and collect pollen loads less constant in species composition. We tested these predictions with 80 colonies of commercially reared Bombus impatiens Cresson placed in 20 landscapes spanning a gradient of agricultural intensification in southern Québec, Canada. We estimated weekly rate at which workers entered and exited colonies and captured eight workers per colony over a period of 14 weeks during the spring and summer of 2016. Captured workers had their wing, thorax, head, tibia, and dry weight measured, as well as their pollen load extracted and identified to the lowest possible taxonomic level. We did not detect any effect of landscape habitat composition on worker morphology or body weight, but found that foraging activity decreased with intensive crops. Moreover, higher diversity of local floral resources led to lower pollen constancy in intensively cultivated landscapes. Finally, we found a negative correlation between the size of workers and the diversity of their pollen load. Our results provide additional evidence that conservation actions regarding pollinators in arable landscapes should be made at the landscape rather than at the farm level.
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.
- Department of Phytology
About Valérie Fournier
- I am full professor at Laval University and my research focuses on agricultural entomology and ecology of insects and mites. I am interested in wild pollinators’ biodiversity, honeybee’s health, beneficial insects’ conservation, crop protection and biological control. My work is often linked with pesticides, either assessing their impacts or developing tools to reduce their use. I supervised more than 30 graduate students, led more than 20 projects and published in high impact journals.