Neonicotinoid pesticides, often used as seed coatings, is likely cause of bee colony deaths being seen in many countries.
Quote from study:
Overall neonicotinoid residues were detected infrequently and rarely exceeded 1.5 ng g−1 (w/w). As such, direct mortality effects caused by exposure to high concentrations of neonicotinoids are likely to be rare (table S12). However, our results suggest that exposure to low levels of neonicotinoids may cause reductions in hive fitness that are influenced by a number of interacting environmental factors. Such interacting environmental factors can amplify the impact of honey bee worker losses (e.g., through sublethal toxicity effects) and reduce longer-term colony viability.
Neonicotinoids were developed by Shell and Bayer as a safer pesticide because they have less effects on birds and mammals. Long suspected to be behind the honey bee colony collapse disorder, they were restricted by the EU in 2013.
We can't abandon the concept of pesticides/fungicides/herbicides soon enough.
