Influence du paysage de bleuetières sur les communautés de pollinisateurs indigènes du Lac-St-Jean et évaluation du potentiel de pollinisation des pollinisateurs du bleuet nain

La pollinisation entomophile est un service écosystémique essentiel à la productivité de nombreuses cultures. Dans les agroécosystèmes, on observe généralement une diminution des pollinisateurs indigènes lorsqu'on s'éloigne des milieux naturels. Dans cette étude, nous avons évalué l'effet des milieux naturels et semi-naturels sur l'abondance et la richesse spécifique des pollinisateurs indigènes dans les bleuetières au Lac-St-Jean. Nos résultats démontrent que les pollinisateurs sont peu influencés par ces habitats, puisqu'ils sont majoritairement des nicheurs de sol, dépendant peu des zones boisées pour leur nidification. En revanche, on retrouve une abondance et une richesse spécifique supérieure en périphérie des bordures de forêt, étant donné qu'on y retrouve une disponibilité accrue en ressources nutritionnelles attrayantes pour ces insectes. De plus, ce projet a permis d'identifier des espèces possédant un meilleur potentiel de pollinisation, dû à leur grande capacité de transport de pollen et de leur spécificité vis-à-vis la fleur de Vaccinium angustifolium

Karshomyia caulicola (Diptera: Cecidomyiidae) Associated with Sclerotinia-Infected Soybean in the United States and Canada

The white-mold gall midge, Karshomyia caulicola Coquillett, was documented in association with soybean, Glycine max (L.) Merr., infected with the fungus Sclerotinia sclerotiorum (Lib.) de Bary. This mycetophagous cecidomyiid appears widespread in the northern soybean producing region, with confirmed detections from Minnesota, North Dakota and Québec. Though likely not a pest of soybean plants, the presence of K. caulicola in soybean fields may complicate identification, population assessment and decision making for soybean gall midge, Resseliella maxima Gagné, which is a recently described pest of soybean. Here, we provide an overview of the known biology and distribution of K. caulicola and descriptions to aid in distinguishing these two cecidomyiids

Palearctic flea beetle and pest of hops and Cannabis, Psylliodes attenuata (Coleoptera, Chrysomelidae, Galerucinae), new to North America

The univoltine leaf beetle Psylliodes attenuata (Koch, 1803) is a pest of Cannabis and Humulus (Cannabaceae) and native to the Palaearctic Region, known from eastern Asia to western Europe.First North American records are presented for P. attenuata from Canada: Ontario and Québec. Adult beetle feeding damage to hops Humulus lupulus L. (Cannabacaea) plants is recorded from Québec. Diagnostic information is presented to distinguish P. attenuata from other North American Chrysomelidae and a preliminary assessment of its potential to spread in North America is presented. While our climate analysis is limited by a lack of data, it appears P. attenuata is physiologically capable of persisting throughout the range of Humulus in North America.The United States of America and Canada are now known to be home to 71 or more species of adventive Chrysomelidae

Efficiency in pollen foraging by honey bees: Time, motion and pollen depletion on flowers of <i>Sisyrinchium palmifolium</i> Linnaeus (Asparagales: Iridaceae)

<p>Honey bees depend on flower resources (nectar and pollen) to supply individual and colony needs. Although behavioural studies already assessed optimum foraging patterns of bumblebees, honey bees foraging behavioural patterns have been poorly assessed. We used <i>Sysirinchium palmifolium </i>L. (Iridaceae), a low-growing, abundant and anthophilous grassland flower to test the hypotheses that <i>Apis mellifera </i>workers would i) spend more time, ii) visit a greater number of flowers, and iii) travel greater distances within patches of <i>S. palmifolium </i>which were newly opened or not been visited by other pollinators when compared to foraging on patches that were available to pollinators during its whole blooming period (only one day). In two different sunny days, we measured bee activities in an area opened for visitation during the whole anthesis (OP plot treatment) and another opened for visitation only half of anthesis (CL plot treatment). We observed bees spending more time, visiting more flowers and travelling more in <i>S. palmifolium</i> CL treatment than the OP plot treatment. Previous studies already showed bees alter their foraging behaviour in the lack of resources. Honey bees are able to remember the period of the day when resources are usually the higher, they probably detect the most promising period to gather resources on <i>S. palmifolium</i> flowers. Since <i>A. mellifera</i> is a pollinator with a wide-distribution and is considered an important cause of changes on native pollinator communities, we support additional studies evaluating its foraging behaviours to better understand how it explores flower resources.</p