Neonicotinoids - Bad for Bees

In December of this year the two year moratorium on the use of three Neonicotinoid pesticides comes to an end. Unless action is taken these chemicals will be used again, releasing them into the environment.

How do these pesticides work?

Neonicotinoids (neonics) are a group of pesticides which work as neurotoxins, attacking the nervous system of the insect. They are systemic, so can be taken up by the crop plant from the soil and transported to all parts of the plant. They are extremely effective at killing the targeted pest, but evidence is growing that they are bad for bees.

Neonics have been in use since the 90's and were seen by many as a useful alternative to the organophosphates of the seventies and eighties and all the problems that went with them.

What's the problem?

In 1994 a pesticide produced by the chemical giant Bayer, under the trade name of 'Gaucho', the active ingredient of which is a neonic called Imidacloprid, became widely used in France as a seed dressing for the sunflower crop which was becoming more commonly grown. Shortly afterwards massive losses of honey bees in the area were reported. Bees were seen to be disorientated and resting for longer periods than normal. Within a few years the National Union of French Beekeepers (UNAF) reported a loss of up to a third of the registered 1.5 million honey bee colonies.

Various studies were undertaken to look at the link between bee losses and neonics. Those undertaken by Bayer did not show a link. Those performed by the French Ministry of Agriculture, under laboratory conditions, however, showed that a small amount of Imidocloprid - a few parts per million - could impair the bees learning performance. 'Gaucho' was suspended from use until more studies could be carried out.

Unfortunately, various other neonicotinoids were being introduced onto the market and so 'Gaucho' was replaced by the chemical company BASF who brought out 'Regent' with the active ingredient Fipronil. After numerous studies and legal battles 'Regent' and various other products which were based on Fipronil were withdrawn.

In 2006-7 honey bee colony losses returned to a more acceptable level at 10%. The following year chemical giant Syngenta introduced 'Cruiser' with the neurotoxin Thiamethoxam. Losses again rose to 60%.


Professor Dave Goulson, (of Sussex University and the founder of the Bumble Bee Conservation Trust) has been looking into Bumble bee decline in this country and has shown that bumbles are effected by neonics leading to reduced colony survival.

He has also studied chemical persistence in the ground. Neonics have been found in soil up to five years after the chemical was last used. There is evidence that these chemicals move with water in the soil and are then taken up by surrounding vegetation.

Evidence of the link between neocotinoids and danger to bees is growing. A Harvard study in 2014 replicated an earlier study, strengthening the link between neonicotinoids and collapse of honey bee colonies. And a study published in Nature on 22 April this year found that bees may become addicted to nicotine-like pesticides in the same way humans get hooked on cigarettes.

Neonicotinoids are used in a vast number of products from the chemical that is used to control fleas on cats and dogs to a large number of over the counter garden products. The moratorium which ends in December covers only three chemicals, Clothianin, Imidocloroprid, and Thametoxam, and only for the specific use on seed treatments.

Over the last twenty years not only have we seen a decline in the number of bee species and pollinators but also our song birds, and small mammals. Is there a link with the use of these chemicals? If a link in a food chain is broken or damaged, the repercussions can be severe.

What can we do?

The chemical companies have been working hard to lift the ban. Theirs is a business worth billions.
Our present government does not support the European ban, so please write to your MP asking for the moratorium to become a ban and for the widespread use of other neonics to be carefully studied.

And when you buy flowering plants for your garden ask how they were produced. Take note of what chemicals were used.

Simon O'Sullivan, professional grower/ gardener, bee keeper.