Common Pesticides Put Bees at Risk

EU says commonly used pesticides, known as neonicotinoids, have serious effects on bee.

Published on: Jan 21, 2013

A report released by the European Food Safety Authority has linked commonly used pesticides, known as neonicotinoids, to serious effects on bee populations. EFSA indicates "high risks" in the use of neonicotinoids and stresses that there are major gaps in available data. These gaps raise fundamental questions about the ability of current safety testing to assess risks posed by pesticides on the environment and health, said Greenpeace.

EFSA scientists report they have identified a number of risks posed to bees by three neonicotinoid insecticides. The Authority was asked by the European Commission to assess the risks associated with the use of clothianidin, imidacloprid and thiamethoxam as seed treatment or as granules, with particular regard to: their acute and chronic effects on bee colony survival and development; their effects on bee larvae and bee behavior; and the risks posed by sub-lethal doses of the three substances. In some cases EFSA was unable to finalize the assessments due to shortcomings in the available data.

The European Food Safety Authority (EFSA) indicates "high risks" for bees in the use of neonicotinoids but stresses that there are major gaps in available data.
The European Food Safety Authority (EFSA) indicates "high risks" for bees in the use of neonicotinoids but stresses that there are major gaps in available data.

The risk assessments focused on three main routes of exposure: exposure from residues in nectar and pollen in the flowers of treated plants; exposure from dust produced during the sowing of treated seeds or application of granules; and exposure from residues in guttation fluid produced by treated plants.

*Exposure from pollen and nectar

Only uses on crops not attractive to honey bees were considered acceptable.

*Exposure from dust

A risk to honey bees was indicated or could not be excluded, with some exceptions, such as use on sugar beet and crops planted in glasshouses, and for the use of some granules.

*Exposure from guttation

The only risk assessment that could be completed was for maize treated with thiamethoxam. In this case, field studies show an acute effect on honey bees exposed to the substance through guttation fluid.

EFSA's conclusions contain tables listing all authorized uses for seed treatment and as granules of the three substances in the EU and indicating for each route of exposure: where a risk has been identified; where a low risk has been identified; or where an assessment could not be finalized because of a lack of data.