Bee-killing pesticides in particular pose the most direct risk to pollinators. The main reasons for global bee-decline are linked to industrial agriculture, parasites/pathogens and climate change. The loss of biodiversity due to monocultures and the wide-spread use of bee-killing pesticides are particular threats for honeybees and wild pollinators. Although the relative role of insecticides in the global decline of pollinators remains poorly characterised, it is becoming increasingly evident that some insecticides, at concentrations applied routinely in the current chemical-intensive agriculture system, exert clear, negative effects on the health of pollinators Б both individually and at the colony level. The observed, sub-lethal, low-dose effects of insecticides on bees are various and diverse.
The European Food Safety Authority (EFSA) has carried out reviews of the neonicotinoid pesticides thiamethoxam, imidacloprid and clothianidin in order to assess the possible risks posed by these systemic insecticides to bees. These reviews helped underpin the decision by the European Commission to ban the three active ingredients from certain applications for a period of two years.

In particular, the reviews identified shortcomings and gaps in the available data which prevented an holistic and exhaustive risk assessment from being carried out. One key uncertainty identified by EFSA in each case related to the role of guttation fluid exuded by commercial…