The nature of receptor binding by imidacloprid is of fundamental importance for risk assessment. If, as Bayer and Syngenta-sponsored scientists now infer, receptor binding is reversible, the toxicity of imidacloprid would be concentration-dependent only, and there would likely be a threshold
concentration below which there would be no adverse effects. However, studies of the Universities of Utrecht and Nijmegen showed that the pollution of surface water with imidacloprid quantitatively correlated with decline of invertebrates and insects-dependent bird species. Moreover, research in the National Park Dwingelderveld, The Netherlands, and in a nature reserve in Krefeld, Germany, showed that, since the introduction of imidacloprid in the mid-1990’s, at least three-quarters of the ground beetles and flying insects have disappeared. The fact of the matter is that irreversible receptor binding and associated time-reinforced toxicity resulting from prolonged exposure to infinitesimal imidacloprid concentrations in the environment would explain the observed correlations with decline of invertebrates and insects-dependent bird species. Environmental contamination with neonicotinoids appears to be a major factor in catastrophic insect decline observed since their introduction in the mid-1990s.
Henk A Tennekes. Imidacloprid and the Druckrey-Küpfmüller Equation - The Fundamental Importance of the Nature of Receptor Binding and Associated Adverse Effects. Open Acc J of Toxicol. 2018; 3(5): 555623. DOI: 10.19080/OAJT.2018.03.555623