EFSA confirms risks of neonicotinoids for bees
Since 2013, the use of some neonicotinoids (imidacloprid, clothianidin and thiamethoxam) is restricted because of risks for bees. On February 28, EFSA confirmed that the use of these systemic insecticides in general poses a risk for bees. This results from a new assessment evaluating a huge amount of available data. However, the words “in general” are important: according to EFSA, some uses do pose a risk and others don’t.
Distinctive uses mean different risks
In some cases, EFSA recognizes only a low risk for (honey) bees. An example is the seed coating in sugar and fodder beet. In this case, the exposure and, therefore, the risk for bees is only low. On the other hand, the authority considers that there is a high risk coming from dust drift and guttation water from coated maize seeds. In some cases, the risk couldn’t be determined. Then, EFSA says that a LOW risk wasn’t shown. This means that they use a principle of caution in the cases in which not enough data are available.
To determine a risk, the assessing scientists first determined the exposure routes, i.e. how bees could have contact with neonicotinoids. One is dust drift like in the photo above. In 2008, there were massive colony losses in the Upper Rhine Valley after sowing maize seeds coated with clothianidin. The reason was insufficient quality of the seed coatings – dust with this substance settled on flowering crops nearby, like oilseed rape or fruit trees. The bees foraged on contaminated nectar and pollen and beekeepers saw massive mortality in their colonies. Other, similar incidents happened due to guttation water, mostly on maize. Other exposure routes are residues in nectar and pollen or accumulation in the soil. EFSA assessed mostly data from honey bees.
For bumblebees and solitary bees they assessed much less data. However, the principle of caution applies also in these cases. It is still unclear, though, if there is a higher risk for wild bees due to their different life histories.
EFSA confirms risk – what are the consequences?
Though the overall conclusion is the confirmation of the risks for bees from seed coatings with neonicotinoids, EFSA doesn’t recommend a general ban of these substances. This is not in its authority. It is the responsibility of the European Commission and the risk managers of the Member States in the EU to determine the rules for future uses. This means that the process goes on – it may take some time until there is a final decision.