Andmebaasi logo

PKI publikatsioonid

Selle valdkonna püsiv URIhttp://hdl.handle.net/10492/3348

Sirvi

Sirvi PKI publikatsioonid Autor "Alaux, Cedric" järgi

Nüüd näidatakse 1 - 4 4
  • Pisipilt
    Kirje
    Acute and chronic effects of agrochemicals, and their synergistic interactions, on bees: Deliverable D3.3
    (PoshBee, 2022) Barascou, Lena; Brown, Mark JF; Costa, Cecilia; de la Rúa, Pilar; de Miranda, Joachim; di Prisco, Gennaro; Forsgren, Eva; Gekière, Antoine; Hellström, Sara; Jürison, Margret; Le Conte, Yves; Linguadoca, Alberto; Mahmood, Ferozah; Mänd, Marika; Martínez-López, Vicente; Medrzycki, Piotr; Morrison, Morgan; Neumann, Peter; Onorat, Piero; Paxton, Robert; Sene, Deborah; Siviter, Harry; Straw, Edward A; Strobl, Verena; Yanez, Orlando; Alaux, Cedric
    Inter-individual differences in pesticide sensitivity may trigger variability in the risk posed by pesticides. Therefore, to better inform pesticide risk assessment for bees, we studied the variability of responses to several pesticides based on endogenous (developmental stage, genetic background, caste) and exogenous factors (pesticide co-exposure). We mainly investigated the toxicity of the insecticide sulfoxaflor, the fungicide azoxystrobin and the herbicide glyphosate. We first used LD50 tests to determine the acute oral and contact toxicity of these pesticides across the different bee species, developmental stages (larva vs adult in honey bees), castes (honey bee and bumble bee workers, queens and drones), and genetic backgrounds (honey bee subspecies). We then considered the risks posed by chronic and sublethal exposures to pesticides by implementing behavioural and reproductive endpoints in the screening of pesticide toxicity. Data showed that azoxystrobin and glyphosate under the test conditions were mildly toxic to bees. However, a large variability in bee sensitivity to sulfoxaflor was found, especially across species and individuals of different castes or sex. This variability is therefore important to consider for increasing the safety margin of the risk posed by insecticides in bees. Several effects induced by sublethal concentrations or doses of pesticides are also described, such as the occurrence of a Non-Monotonic Dose-Response (NMDR) and delayed effects in honey bees, impairment of reproductive performances in bumble bees, and a decreased longevity of Osmia adult females (although no effects were found on larval development). Finally, an interaction between pesticides was found when exposure was by contact, but not under oral exposure. In conclusion, the range of effects described here provides very useful insights for better understanding the toxicity of pesticides and therefore the risks they might pose to bees.
  • Pisipilt
    Kirje
    Improved protocols for testing agrochemicals in bees: Deliverable D3.2
    (PoshBee, 2021) Medrzycki, Piotr; Hellström, Sara; Straw, Edward; Linguadoca, Alberto; Jürison, Margret; Alaux, Cedric; Barascou, Lena; Brown, Mark; Costa, Cecilia; De la Rúa, Pilar; de Miranda, Joachim Rodrigues; di Prisco, Gennaro; Forsgren, Eva; Karise, Reet; Le-Conte, Yves; Mänd, Marika; Martínez-López, Vicente; Neumann, Peter; Onorati, Piero; Paxton, Robert; Sene, Deborah; Strobl, Verena; Yanez, Orlando
    Within the PoshBee Project, we have worked out precise protocols for testing the toxicological endpoints and metabolisation rate of agrochemicals on and in bees. Three agrochemical classes (insecticides, fungicides and herbicides) were tested on three bee groups (honey bees, bumble bees and solitary mason bees). The specific protocols, different for each combination of the pesticide class and bee group, were designed based on the existing toxicity testing methods and modified according to the specificities of the different bee groups, their castes and the different exotoxicological features of the compounds. Sulfoxaflor, Azoxystrobin, and Glyphosate were used respectively as examples of the three pesticide classes. Apis mellifera, Bombus terrestris and Osmia bicornis were chosen as the examples of the three bee groups. The protocols for honey bees and bumble bees were designed based on the official existing guidelines edited by OECD. Nevertheless, given that the OECD guidelines provide recommendations to fit with most agrochemicals, many of the parameters are defined with low precision in order to be flexible and adapt to different categories of molecules. While OECD has no guidelines for testing solitary bees, we used information from the unpublished ring test protocols for Osmia bicornis by the ICPPR non- Apis working group.
  • Pisipilt
    Kirje
    Manuscript of toxicokinetics of three agrochemicals in three model bee species: Deliverable D3.1
    (PoshBee, 2022) Costa, Cecilia; Di Prisco, Gennaro; Alaux, Cedric; Onorati, Piero; Jürison, Margret; Karise, Reet; Mänd, Marika; Hellström, Sara; Medrzycki, Piotr
    As part of the activities foreseen by the POSHBEE project, we performed experiments to verify the toxicokinetics of three pesticides (the insecticide sulfoxaflor, the fungicide azoxystrobin and the herbicide glyphosate) in the bodies of social bees (Apis mellifera and Bombus terrestris) and solitary bees (Osmia bicornis). For each species all castes and sexes were studied. Based on the results from dose-response assays, sublethal doses were used to treat individuals, which were exposed to the chosen pesticides orally and by contact. Bees were then sampled at multiple time points post- exposure, to capture the breakdown of the active ingredients in the bodies of the organisms. Results of the chemical analyses on bee samples were used for the evaluation of the dynamics of the oral and contact acute exposure in the three species. Overall, the active ingredients sulfoxaflor, azoxystrobin and glyphosate degrade in all species, sex or caste. Nevertheless, there were some exceptions: in honey bee workers, glyphosate administered topically and azoxystrobin administered via the oral route seemed to remain stable in the bees’ bodies even 10 days after exposure (11% and 13% of degradation rate, respectively). We also observed a low degradation of sulfoxaflor following topical exposure in bumble bee queens (26% of degradation rate) and in Osmia bee females (22% of degradation rate). In bumble bees exposed topically to glyphosate degradation was lower than 50% for all sexes and castes. These results deserve further attention by researchers to understand the destiny of these molecules in the bee body and their effects therein.
  • Pisipilt
    Kirje
    Synthesising the toxicokinetics and toxicodynamics of agrochemicals on bees: Deliverable D3.4
    (PoshBee, 2022) Jürison, Margret; Alaux, Cedric; Barascou, Lena; Brown, Mark JF; Costa, Cecilia; de la Rúa, Pilar; de Miranda, Joachim; di Prisco, Gennaro; Forsgren, Eva; Gekière, Antoine; Hellström, Sara; Le Conte, Yves; Linguadoca, Alberto; Karise, Reet; Mahmood, Ferozah; Mänd, Marika; Martínez- López, Vicente; Medrzycki, Piotr; Morrison, Morgan; Neumann, Peter; Onorat, Piero; Paxton, Robert; Sene, Deborah; Siviter, Harry; Straw, Edward A; Strobl, Verena; Yanez, Orlando
    Within the PoshBee Project we have tested three bee species – honey bees Apis mellifera, bumble bees Bombus terrestris and solitary bees Osmia bicornis – for their sensitivity to pesticides and analysed the clearance of pesticides from bees. For each species, all castes and sexes were studied. We synthesised the mortality data (LD50 or results of limit tests) with the toxicokinetic patterns and analysed this against the background of inter- and intraspecific variation in life-histories of the tested bees. The clearance of sulfoxaflor is relatively similar across all bee species tested and in females after contact treatment it tends to be retained. The toxicity increases over time independently of the clearance from the body. The clearance of azoxystrobin was rapid in Osmia and bumble bees, as well as in honey bee queens, but in honey bee workers there was very little clearance. Similar to sulfoxaflor the toxicity increased over time, although the residues were detected at very low levels. Glyphosate tended to be retained in bumble bees after contact treatment but cleared rapidly after oral treatment. For Osmia bees only in males after contact treatment was the glyphosate almost lost. The toxicity of a pesticide is dependent on the exact dosage, but also the exposure route and time, as well as the speed of detoxification and clearance from a body. The assessment for the hazard that a less toxic pesticide might pose, can be largely dependent on the exposure route. The effects of pesticide toxicity can increase even after the molecules have been cleared out of the body.