The homing flight method to assess the effect of sublethal doses of plant protection products on the honey bee in field conditions: results of the ring tests

The evaluation of the potential effects of plants protection products on honeybee behavior is considered as part of the risk assessment according to Regulation (EC) No 1107/2009 and the EFSA Guidance document (EFSA 2013). But no standardized and validated method is still available. With current revisions of plant protection product risk assessment on the honeybee, a European ring test is conducted since 2015 with 11 voluntary laboratories to test a methodology assessing the effects of sublethal doses of a plant protection product administered in controlled conditions on the homing capacity of forager bees in the field. Homing success is measured by monitoring free-ranging honey bees with radio-frequency identification (RFID) tagging technology

Long-term field-realistic exposure to a next-generation pesticide, flupyradifurone, impairs honey bee behaviour and survival

10openInternationalInternational coauthor/editorThe assessment of pesticide risks to insect pollinators have typically focused on short-term, lethal impacts. The environmental ramifications of many of the world’s most commonly employed pesticides, such as those exhibiting systemic properties that can result in long-lasting exposure to insects, may thus be severely underestimated. Here, seven laboratories from Europe and North America performed a standardised experiment (a ring-test) to study the long-term lethal and sublethal impacts of the relatively recently approved ‘bee safe’ butenolide pesticide flupyradifurone (FPF, active ingredient in Sivanto®) on honey bees. The emerging contaminant, FPF, impaired bee survival and behaviour at field-realistic doses (down to 11 ng/bee/day, corresponding to 400 µg/kg) that were up to 101-fold lower than those reported by risk assessments (1110 ng/bee/day), despite an absence of time-reinforced toxicity. Our findings raise concerns about the chronic impact of pesticides on pollinators at a global scale and support a novel methodology for a refined risk assessmentopenTosi, Simone; Nieh, James C; Brandt, Annely; Colli, Monica; Fourrier, Julie; Giffard, Herve; Hernández-López, Javier; Malagnini, Valeria; Williams, Geoffrey R; Simon-Delso, NoaTosi, S.; Nieh, J.C.; Brandt, A.; Colli, M.; Fourrier, J.; Giffard, H.; Hernández-López, J.; Malagnini, V.; Williams, G.R.; Simon-Delso, N

Docosahexaenoic acid-containing choline phospholipid modulates LPS-induced neuroinflammation in vivo and in microglia in vitro

BACKGROUND: Neuroinflammatory processes are considered a double-edged sword, having both protective and detrimental effects in the brain. Microglia, the brain's resident innate immune cells, are a key component of neuroinflammatory response. There is a growing interest in developing drugs to target microglia and control neuroinflammatory processes. In this regard, docosahexaenoic acid (DHA), the brain's n-3 polyunsaturated fatty acid, is a promising molecule to regulate pro-inflammatory microglia and cytokine production. Several works reported that the bioavailability of DHA to the brain is higher when DHA is acylated to phospholipid. In this work, we analyzed the anti-inflammatory activity of DHA-phospholipid, either acetylated at the sn-1 position (AceDoPC, a stable form thought to have superior access to the brain) or acylated with palmitic acid at the sn-1 position (PC-DHA) using a lipopolysaccharide (LPS)-induced neuroinflammation model both in vitro and in vivo. METHODS: In vivo, adult C57Bl6/J mice were injected intravenously (i.v.) with either AceDoPC or PC-DHA 24 h prior to LPS (i.p.). For in vitro studies, immortalized murine microglia cells BV-2 were co-incubated with DHA forms and LPS. AceDoPC and PC-DHA effect on brain or BV-2 PUFA content was assessed by gas chromatography. LPS-induced pro-inflammatory cytokines interleukin IL-1β, IL-6, and tumor necrosis factor (TNF) α production were measured by quantitative PCR (qPCR) or multiplex. IL-6 receptors and associated signaling pathway STAT3 were assessed by FACS analysis and western-blot in vitro. RESULTS: In vivo, a single injection of AceDoPC or PC-DHA decreased LPS-induced IL-6 production in the hippocampus of mice. This effect could be linked to their direct effect on microglia, as revealed in vitro. In addition, AceDoPC or PC-DHA reduced IL-6 receptor while only AceDoPC decreased IL-6-induced STAT3 phosphorylation. CONCLUSIONS: These results highlight the potency of administered DHA-acetylated to phospholipids-to rapidly regulate LPS-induced neuroinflammatory processes through their effect on microglia. In particular, both IL-6 production and signaling are targeted by AceDoPC in microglia.Metabolism in human of a structured phospholipid from marine origin and neural effec

Recherche méthodologique pour évaluer les effets des pesticides chez l'abeille : enregistrement du comportement individuel à l'aide de puces électroniques

National audiencePour étudier l'impact des pesticides sur le comportement de l'abeille domestique, les techniques classiques n'offrent qu'un suivi simultané pour un nombre limité d'individus, et cela sur une durée d'observation de quelques heures seulement. Pourtant des outils modernes de télédétection et d'identification peuvent s'appliquer en écotoxicologie comportementale. A cet égard, les puces électroniques RFID (Radio Fréquency Identification Device) permettent de suivre automatiquement un grand nombre d'insectes, enregistrés de façon simultanée. La lecture très rapide (millisecondes) s'effectue à travers plusieurs barrières physiques (propolis, colle, plastique, bois...). Le travail mené ici montre l'intérêt de cette technique d'enregistrement du comportement individuel des abeilles avec la problématique des pesticides pouvant affecter leurs traits d'histoire de vie

Effect of an omega-3/antioxidants supplemented diet on emotional and cognitive alterations and neuroinflammatory processes associated with obesity

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Effect of an omega-3/antioxidants supplemented diet on emotional and cognitive alterations and neuroinflammatory processes associated with obesity

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Effet d'une diète enrichie en acides gras polyinsaturés n-3 et en antioxydants sur les altérations émotionnelles et cognitives associées à l'obésité

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Honeybee tracking with microchips: a new methodology to measure the effects of pesticides

International audienceLosses of foraging bees are sometimes attributed to altered flight pattern between a meliferous plant treated with an insecticide and the hive. Only a limited number of studies has investigated the impact of pesticides on homing flight due to the difficulty of measuring the flight time between the food source and the hive. Monitoring the flights of the foraging bees needs their individual identification. The number of bees monitored simultaneously and the time span during which observations can be made limit most of the monitoring techniques. However, techniques of automatic tracking and identification of individuals have the potential to revolutionize the study of the ecotoxicological effects of xenobiotics on the bee behaviors. Radio Frequency Identification (RFID) offer numerous advantages such as an unlimited number of codes, a large number of simultaneous recording, and a quick reading, especially through materials (e.g., wood). The aim of this study was to show how the RFID device can be used to study the effects of pesticides on both the behavioral traits and the lifespan of bees. In this context, we have developed a method under tunnel to automatically record the displacements of foragers individualized with RFID tags and to detect the alteration of the flight pattern between an artificial feeder and the hive. Fipronil was selected as test substance due to the lack of information on the effects of this insecticide on the foraging behavior of free-flying bees. We showed that oral treatment of 0.3 ng of fipronil per bee (LD50/20) reduced the number of foraging trips. The strengths of our approach were briefly discussed