Neonicotinoids (neonics) are a relatively new type of insecticide, used in the last 20 years to control a variety of pests, especially sap-feeding insects, such as aphids on cereals, and root-feeding grubs.
Neonics are systemic pesticides. Unlike contact pesticides, which remain on the surface of the treated foliage, systemics are taken up by the plant and transported to all the tissues (leaves, flowers, roots and stems, as well as pollen and nectar). Products containing neonics can be applied at the root (as seed coating or soil drench) or sprayed onto crop foliage. The insecticide toxin remains active in the plant for many weeks, protecting the crop season-long.
Neonicotinoids in Agriculture
In the UK, five neonicotinoid insecticides are authorised for use in agriculture: acetamiprid; clothianidin; imidacloprid; thiacloprid; and thiamethoxam. They are used as:
- seed treatments for cereals and sugar beet (the widest use)
- soil treatment for pot plants in the ornamental sector
- treatment for turf in the amenity sector
- foliar sprays on apples, pears and a range of glasshouse crops
Neonicotinoids, especially seed treatments of imidacloprid, clothianidin and thiamethoxam on arable crops, have become of increasing concern to beekeepers and bee researchers in recent years with many of them suspecting that they may be connected to current bee declines.
Risk to Bees and Other Pollinators
In 2013, the European Union’s pesticide risk assessors revised their conclusions to recognise that use of these three neonics on flowering crops can pose a high risk to bees. Since then, EU countries have implemented a partial ban on imidacloprid, clothianidin and thiamethoxam use, prohibiting most uses on crops attractive to bees. These include oilseed rape, maize, sunflowers, and products sold to the public. Uses in greenhouses, winter sown cereals and as foliar sprays on crops after flowering are still permitted, while there are no restrictions on another two neonics, acetamiprid and thiacloprid.