title: Quantification of imidacloprid uptake in maize crops.
abstract: The systemic imidacloprid is one of the most used insecticides in the world for field and horticultural crops. This neurotoxicant is often used as seed-dressing, especially for maize, sunflower, and rape. Using a LC/MS/MS technique (LOQ = 1 microg/kg and LOD = 0.1 microg/kg), the presence of imidacloprid has been measured in maize from field samples at the time of pollen shed, from less than 0.1 microg/kg up to 33.6 microg/kg. Numerous random samples were collected throughout France from 2000 to 2003. The average levels of imidacloprid measured are 4.1 microg/kg in stems and leaves, 6.6 microg/kg in male flowers (panicles), and 2.1 microg/kg in pollen. These values are similar to those found previously in sunflower and rape. These results permit evaluation of the risk to honeybees by using the PEC/PNEC ratios (probable exposition concentrations/predicted no effect concentration). PEC/PNEC risk ratios were determined and ranged between 500 and 600 for honeybees foraging on maize treated with imidacloprid by seed dressing. Such a high risk factor can be related to one of the main causes of honeybee colony losses.
authors.affiliation: Centre de biophysique moléculaire, CNRS (Centre National de la Recherche Scientifique) & Université d'Orléans, France. bonmantin@cnrs-orleans.fr
authors.forename: J M
authors.initials: JM
authors.lastname: Bonmatin
authors.forename: P A
authors.initials: PA
authors.lastname: Marchand
authors.forename: R
authors.initials: R
authors.lastname: Charvet
authors.forename: I
authors.initials: I
authors.lastname: Moineau
authors.forename: E R
authors.initials: ER
authors.lastname: Bengsch
authors.forename: M E
authors.initials: ME
authors.lastname: Colin
mesh_terms: D035264:Flowers / Q000737:chemistry; D007093:Imidazoles / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism*; D000073943:Neonicotinoids; D009574:Nitro Compounds; D018515:Plant Leaves / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D011058:Pollen / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry / Q000378:metabolism*
chemical_list: D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; C082359:imidacloprid