La transfrontalièrité : le cas de la Turquie

Difficile à classer, la Turquie est à la fois un pays européen, balkanique, moyen-oriental, asiatique et méditerranéen, avec une façade importante sur la "mer nourricière". Elle porte en elle-même toute la diversité et les contradictions de ces aires auxquelles elle appartient géographiquement et culturellement. Elle est attirée, depuis plus d'un siècle, par trois pôles de "civilisation"; par l'Asie centrale, par ses liens culturels, affectifs et linguistiques; par le monde arabe, par ses att..

Le séisme en Turquie (compte rendu du colloque tenu au CERI)

La réunion organisée « à chaud » par le Centre d'études et de recherches internationales de la Fondation nationale des sciences politiques, a pour objectif de tenter une première approche, qui se veut pluridisciplinaire, des politiques, des pratiques, des faits et des perspectives en relation avec le récent séisme d'Izmit en Turquie (17 août 1999)

Reduced-risk insecticides in Neotropical stingless bee species: impact on survival and activity

Background: As honeybees are the main pollinator species subject to an intense research regarding effects of pesticides, other ecologically important native bee pollinators have received little attention in ecotoxicology and risk assessment of pesticides in general, and insecticides in particular, some of which are perceived as reduced-risk compounds. Here the impact of three reduced-risk insecticides – azadirachtin, spinosad, and chlorantraniliprole – was assessed in two species of stingless bees, Partamona helleri and Scaptotrigona xanthotrica, which are important native pollinators in Neotropical America. The neonicotinoid imidacloprid was used as a positive control.Results: Spinosad exhibited high oral and contact toxicities in adult workers of both species at the recommended label rates, with median survival times (LT50s) ranging from 1 to 4 h, whereas these estimates were below 15 min for imidacloprid. Azadirachtin and chlorantraniliprole exhibited low toxicity at the recommended label rates, with negligible mortality that did not allow LT50 estimation. Sublethal behavioral assessments of these two insecticides indicated that neither one of them affected the overall group activity of workers of the two species. However, both azadirachtin and chlorantraniliprole impaired individual flight take-off of P. helleri and S. xanthotrica worker bees, which may compromise foraging activity, potentially leading to reduced colony survival.Conclusion: These findings challenge the common perception of non-target safety of reduced-risk insecticides and bioinsecticides, particularly regarding native pollinator species.Keywords: behavioral impact; biopesticides; colony and individual level effects; native bee pollinators; sublethal effect

Imidacloprid-Induced Impairment of Mushroom Bodies and Behavior of the Native Stingless Bee Melipona quadrifasciata anthidioides

Declines in pollinator colonies represent a worldwide concern. The widespread use of agricultural pesticides is recognized as a potential cause of these declines. Previous studies have examined the effects of neonicotinoid insecticides such as imidacloprid on pollinator colonies, but these investigations have mainly focused on adult honey bees. Native stingless bees (Hymenoptera: Apidae: Meliponinae) are key pollinators in neotropical areas and are threatened with extinction due to deforestation and pesticide use. Few studies have directly investigated the effects of pesticides on these pollinators. Furthermore, the existing impact studies did not address the issue of larval ingestion of contaminated pollen and nectar, which could potentially have dire consequences for the colony. Here, we assessed the effects of imidacloprid ingestion by stingless bee larvae on their survival, development, neuromorphology and adult walking behavior. Increasing doses of imidacloprid were added to the diet provided to individual worker larvae of the stingless bee Melipona quadrifasciata anthidioides throughout their development. Survival rates above 50% were only observed at insecticide doses lower than 0.0056 µg active ingredient (a.i.)/bee. No sublethal effect on body mass or developmental time was observed in the surviving insects, but the pesticide treatment negatively affected the development of mushroom bodies in the brain and impaired the walking behavior of newly emerged adult workers. Therefore, stingless bee larvae are particularly susceptible to imidacloprid, as it caused both high mortality and sublethal effects that impaired brain development and compromised mobility at the young adult stage. These findings demonstrate the lethal effects of imidacloprid on native stingless bees and provide evidence of novel serious sublethal effects that may compromise colony survival. The ecological and economic importance of neotropical stingless bees as pollinators, their susceptibility to insecticides and the vulnerability of their larvae to insecticide exposure emphasize the importance of studying these species

«La Turquie du séisme». Séminaire de recherche Centre d'études et de recherches internationales (Fondation nationale des sciences politiques). 16 septembre 1999

Chartol-Gökaltay S., Rigoni Isabelle, Vaner Semih. «La Turquie du séisme». Séminaire de recherche Centre d'études et de recherches internationales (Fondation nationale des sciences politiques). 16 septembre 1999 . In: CEMOTI, n°28, 1999. Turquie Israël. pp. 333-342

«La Turquie du séisme». Séminaire de recherche Centre d'études et de recherches internationales (Fondation nationale des sciences politiques). 16 septembre 1999

Chartol-Gökaltay S., Rigoni Isabelle, Vaner Semih. «La Turquie du séisme». Séminaire de recherche Centre d'études et de recherches internationales (Fondation nationale des sciences politiques). 16 septembre 1999 . In: CEMOTI, n°28, 1999. Turquie Israël. pp. 333-342

Insecticide resistance and size assortative mating in females of the maize weevil (Sitophilus zeamais)

Random mating is a common assumption in studies of insecticide resistance evolution, but seldom tested despite its potential consequences. Therefore, the existing evidence of female choice and insecticide resistance in populations of the maize weevil (Sitophilus zeamais), a key pest of stored cereals, led to the assessment of mating preferences and their association with insecticide resistance in this species. Mixed lines of a maize weevil colony were established from field‐collected populations, which after 5 months of natural breeding were selected for deltamethrin resistance for five generations, reaching over 100‐fold resistance. Mating preference was significantly based on the partner size, measured as body mass (χ2 = 5.83, df = 1, P = 0.016). Susceptible females preferred heavier males for mating (χ2 = 5.83, df = 1, P = 0.015), a trait that was more frequently associated with deltamethrin resistance (χ2 = 7.38, df = 1, P = 0.007). Deltamethrin resistance compromised daily fertility, although the reduced offspring production observed in matings between susceptible females and resistant males was negligible. Susceptible female weevils prefer larger (and heavier) males to mate, a trait associated with deltamethrin resistance, favouring the maintenance and spread of the resistant phenotype in the population

Partis politiques en Turquie - Immigration

De nombreux immigrés d'origine variée (antillaise, indonésienne, méditerranéenne, turque...) vivent aux Pays-Bas et les pouvoirs publics ont pris diverses mesures pour permettre leur intégration et leur participation à la vie politique