The idea was fantastic. Instead of having to spray chemicals on your fields you simply planted a seed that contained a pesticide that would be inside every part of the plant as it grew. This stopped problems of sprays being blown away and so both cut down on costs and helped the environment in one easy move.
We now know that it is not that simple. The first real signs that there might be a problem came in France way back in 1994. Farmers growing sunflowers for their oil found that the neighbouring bee keepers experienced serious losses in their colonies. The hives themselves seemed healthy but the number of bees returning to the hive after collecting pollen was radically reduced which resulted in a lot of the colonies failing. Then problems emerged in the US. Once again large numbers of colonies collapsed.
But there wasn’t a simple and direct correlation between the planting of neonicitinoid seeds and the death of bee colonies. In many localities the seeds were being used without obvious problems whereas in others bees were dying when they weren’t.
So the companies producing these chemicals re-ran their tests and produced evidence that seemed to show that it was simply not possible for any bee to get a fatal dose of neonicitinoids in real life practical conditions.
This has resulted in huge controversy between environmental organisations claiming evil chemical corporations are killing our pollinators and others claiming that there was a lot of fuss about nothing.
The chemical companies had a point. It really is very hard to kill a bee by exposing it to levels of neonicitinoids that it might encounter collecting pollen from a variety of plants in the wild.
But we environmental campaigners have looked into it in more detail and the truth is rather more complex than the chemical companies want to admit. Bees don’t collect pollen at random. They usually specialise on one particular plant and keep going back to it. Fields of rapeseed can therefore result in an individual bee getting a larger dose than might be expected as it will show a strong tendency to get its food from one prime source.
Then there is the problem of how bee navigation systems work. In a high laboratory dose neonicitinoids kill bees outright. At a lower does they interfere with the bees navigation systems. It is hard enough in the wild for a bee to work out how to get home from up to two miles away, particularly when there are high winds to contend with. They rely on complex neurological systems to navigate using clues like the sun’s position. Even in the best of circumstances bees often get this wrong and return to a different hive.
A heavy enough dose of neonicitinoids causes drastic reductions in the numbers of bees returning and eventually kills the colony. This is why the chemical companies are mistaken. The dose received by a foraging bee can vary enormously depending on what is happening in the environment. In one time and one place you can plant neonicitinoid seeds and no harm at all will be done to the local bee population. At another time and in another place the circumstances will be different and the crop will weaken & kill local colonies.
An important recent study of actual events in the field found exactly this. Neonicitinoids really have damaged honeybees but not in every place at every time. The environmental conditions matter. This wasn’t a piece of research organised by environmental campaigners – it was paid for by the producers of neonicitinoids themselves and published in June in the journal Science.
Further worrying evidence emerged in August. The journal Nature Ecology and Evolution reported that it isn’t only honeybees that are being damaged by neonicitinoids. Bumblebees and other insects are also suffering. The pesticides interfere with their reproductive ability and could even eradicate species.
What is worse is that Neonicitinoids are very persistent. Any part of a living or dead plant which is blown or washed away contains the pesticides. They then concentrate in the soil at the edges of fields near hedgerows where so much of our wildlife lives. Doses much stronger than the concentration found in crops have frequently been detected in these important locations without anyone fully understanding the extent or the implications.
The soil in our fields contains billions of micro-organisims in every teaspoon which are vital for soil health and crop growth. No one has yet done the research into whether any damage is being done to them by neonicitinoid run off. The consequences could be horrific and even if we stopped using these pesticides tomorrow it will take decades for them to be removed from our environment.
The case is therefore proven clear and the UK government needs to put its full weight behind a complete and immediate ban.