Neonicotinoids (neonics for short), are a class of potent insecticides, so potent that only tiny amounts are required to kill insects – including our beloved bees.
Such a powerful chemical cannot be used or licenced as a chemical spray. The primary application method is via seed dressing, where adhesive is used to stick the neonic chemical to the seed before it is provided to the farmer. When the farmer drills the field (plants the seed), and the seed germinates, it takes up some insecticide and renders the plant toxic to sucking or nibbling insects – in other words, it is a systemic poison.
Ever since these chemicals arrived on the market, they have become more and more popular with growers. Even though the dressed seed is more expensive, it circumvents the need for more insecticide spraying, saving on costs and labour.
This sounds good but is it true? Evidence has been emerging that small amounts can be present in the pollen and nectar of flowering crops such as oilseed rape (OSR) and field bean. It can be taken up by the roots of the flowering weed and will be toxic in the same way. Runoff from the seed can pollute rivers and streams.
In January this year, the UK government overturned a ban on neonics that has been in place since 2018. The UK had supported this EU-wide measure banning the three main neonics: clothianidin, imidacloprid and thiamethoxam.
“The weight of evidence now shows the risks neonicotinoids pose to our environment, particularly to the bees and other pollinators which play such a key part in our £100 billion food industry, is greater than previously understood.”Michael Gove 2017 (as environment secretary)
In addition, he said, “I believe this justifies further restrictions on their use. We cannot afford to put our pollinator populations at risk.” See also Evidence for pollinator cost and farming benefits of neonicotinoid seed coatings on oilseed rape.
At the time Gove wrote in the Guardian that, “Unless the evidence base changes again, the government will keep these restrictions in place after we have left the EU.”
The evidence against neonics has only been increasing. Yet despite this, in January, the government went back on its policy when it caved into demands of the NFU and British Sugars and lifted the ban. It has permitted the use, as a seed dressing, of the very neonic that Gove condemned – thiamethoxam.
“In the light of these new studies, continuing to claim that use of neonicotinoids in farming does not harm bees is no longer a tenable position. In my view we should also consider the bigger picture; the current model of farming based on huge monocultures treated with dozens of pesticides is causing devastating environmental harm, undermining vital ecosystem services that keep us all alive.”David Goulson, Professor of Biology at University of Sussex
The Government statement says it is an “emergency authorisation” for the treatment of sugar beet. Sugar beet is being badly affected by beet yellow virus and the pesticide is intended to control the aphid that spreads the virus between plants.
The emergency authorisation has been said to be a loophole that has been used by a number EU countries to allow applicants to get around the legislation. In this case, the NFU and the British Sugars seem to be using the same tactic.
Victoria Prentis, Under-Secretary for Environment, Food and Rural Affairs (DEFRA) said the authorisation was very specific, and “targeted at a non-flowering crop, which bees are not attracted to”.
A great deal of research into neonics has been done and the effect on the environment, the results were often confusing and inconclusive. There seems to be a correlation between neonic use and insect reduction. But is this due to the increased application of this chemical, or is it another of the manifestations of climate change? Over the last few years, it has gradually become clearer that neonics are devastating insect and aquatic life.
It appears that as little as 5% of the pesticide may be absorbed by the target plant and the rest leaches into the soil, where it is taken up by weeds or pollutes water courses and damages aquatic life. A flowering weed could expose pollinating insects to the toxin via its nectar and pollen. Therefore, a herbicide weed control needs to be applied.
“One in every three bites of food we eat requires insect pollination. We depend on insects more that some of us imagine. If we fail to safeguard our environment it will lead to our peril.”Keith Delaplane, Professor of Entomology, University of Georgia, National Honey Show 2008
With the dramatic decline in insect numbers, with more than 40% of species in declining and a third endangered, the rate of extinction is eight times faster than that of mammals, birds and reptiles. The total mass of insects is falling by 2.5% a year, suggesting there could be none within a century.
Neonicotinoids have a half-life (the time taken for half of the chemical to degrade) in soil of over three years. Therefore, legally, no crops that flower can be sown in the treated fields for the following 22 months and oil seed rape, which is particularly attractive to pollinators, for 32 months.