Bijensterfte, oorzaken en gevolgen

The European Beekeeping Coordination (EBC), a task force of professional beekeeping associations from across the EU, is calling for an urgent revision of the way pesticides and their active substances are authorised in the EU. In a leaked memo EPA scientists state that “information from standard tests and field studies, as well as incident reports involving neonicotinoids insecticides (e.g., imidacloprid) suggest the potential for long-term toxic risk to honey bees and other beneficial insects” and they criticise existing approvals research as deficient and request additional tests “for additional chronic testing on bee hive activity (e.g., effects to queen, larvae, etc.).”

Traditionally, pesticides have been sprayed directly onto the plants. But pesticides are now also applied in a systemic way by coating the seeds with a toxic mixture of insecticides and fungicides, injecting pesticides into the soil, irrigating crops with water containing pesticides or by injecting the pesticides directly into the plant. As a result, the plant either soaks up the pesticides during its development or the pesticides are spread directly throughout the whole plant, including the flowers.

Insects feeding on the pollen, the nectar or the plant, or drinking pesticide-treated water, are thereby exposed little by little to the pesticides, that remain in the plant over long periods. Even if the concentrations do not kill them instantly, the repeated exposure to small amounts of pesticides can have serious impacts on the bees‟ health. In addition, systemic pesticides build up in the hive‟s food reserves (made up of nectar, water and pollen, meaning that members of the colony that stay inside the hive are also exposed to the pesticides, not just the bees collecting the food.

So far, the impact of this chronic exposure to contaminated food and water sources on bees and their colonies has been completely ignored in safety assessments. Only acute toxicity, considered as the adverse effects of a pesticide resulting either from a single direct exposure (or from multiple exposures in a short space of time, usually less than 24 hours), and in certain cases the toxicity for larvae has been evaluated. In addition, the methodologies used to assess the impact on adult bees and the colony as a whole do not take account of the long-lasting presence of pesticides in the environment.

In a leaked memo US government scientists warn that bees and other non-target invertebrates are at risk from a new neonicotinoid pesticide licence and that tests in the approval process are unable to detect environmental damage. In the leaked memo the EPA scientists state that “information from standard tests and field studies, as well as incident reports involving other neonicotinoids insecticides (e.g., imidacloprid) suggest the potential for long-term toxic risk to honey bees and other beneficial insects” and they criticise existing approvals research as deficient and request additional tests “for additional chronic testing on bee hive activity (e.g., effects to queen, larvae, etc.).”

Source: Corporate Europe Observatory and the European Beekeeping Coordination, November 2010
http://www.biobees.com/library/background_theory_research/CEO_Neonics_In...

Recent scientific papers on toxicity
– Tennekes H. A. (2010) The Significance of the Druckrey-Kupfmuller Equation for Risk Assessment – The Toxicity of Neonicotinoid Insecticides to Arthropods is Reinforced by Exposure Time. Toxicology. 276 (1), 1-4
– Tennekes H. A. (2011) The Significance of the Druckrey-Kupfmuller Equation for Risk Assessment – The Toxicity of Neonicotinoid Insecticides to Arthropods is Reinforced by Exposure Time: Responding to a Letter to the Editor by Drs. C. Maus and R. Nauen of Bayer CropScience AG. Toxicology (in press)

Full leaked EPA document - http://www.panna.org/sites/default/files/Memo_Nov2010_Clothianidin.pdf