European Union governments this week took a major decision in favour of wildlife by widening an existing EU ban on some pesticides to include the powerful neonicotinoid thiacloprid, developed by chemical giant Bayer.
Conservationists have been fighting for this ban since the EU partially restricted the use of three other neonicotinoid treatments – imidacloprid, clothianidin and thiamethozam – in 2013. They are totally banned in France.
It was a hard-fought-for victory. The Commission came under huge pressure from lobbyists from the chemical industry for thiacloprid’s continued use, but based its assessment on previous findings of the European Food Safety Agency which highlighted concerns about the danger to bees, it being toxic for humans, and despite claims by the manufacturer that it rapidly degrades in the environment it is present in too great a concentration in groundwater.
What are neonicotinoids?
Developed in the 1980s and 1990s, neonicotinoids (or neonics, as they’re widely known for obvious reasons!) are a class of neuro-active insecticides chemically similar to nicotine (which is probably now best known as the addictive substance in cigarettes, but which is actually a naturally-occurring insecticide found in nightshades including tomatoes, potatoes, and green pepper). The name literally means “new nicotine-like insecticides”.
Products containing neonics are applied to plants and crops that both ‘pest’ insects and pollinators visit. They can be applied at the root (as seed coating or soil drench) or sprayed onto crop foliage. The toxins are absorbed and become distributed throughout the plant, including the tips of new vegetation growth. They work by binding to insect cell receptors, disrupting neural transmission in the central nervous system of invertebrates leading to paralysis and death.
No insecticides can discriminate between so-called ‘good’ and ‘bad’ insects – they kill everything that touches them. Neonics are around 7000 times more potent to insects than DDT, the now-banned chemical that ravaged wildlife populations in the 1950s and 1960s and described so eloquently by Rachel Carson in her landmark book ‘Silent Spring’.
The growth in the use of neonics has been startling. In 1990, the global insecticide market was dominated by carbamates, organophosphates, and pyrethroids. By 2008, one-quarter of the insecticide market was neonicotinoid, and imidacloprid had become the world’s largest selling insecticide, registered for use for over 140 crops in 120 countries. By 2009, the global neonicotinoid market was worth US $2.63 billion.
Pesticides are everywhere
Pesticides – the group of toxins that include insecticides, herbicides, and fungicides – are astonishingly commonplace these days. Their use has continued to spiral despite concerns about their impacts on bees and other pollinators and the environment – and humans. Actual sales figues are difficult to obtain, but use by the agricultural sector accounted for nearly 90% of the total pesticide usage between 2005-2012.
It is estimated, however, that 16.9 thousand tonnes of pesticides are now applied by UK farmers annually, and fields in the UK are receiving on average seventeen applications per year.
The ‘cocktail effect’
Manufacturers regularly claim that pesticides are safe if used as per instructions, and are tested before being brought to market. But chemicals are tested individually and under laboratory situations, and usually not in combination with other pesticides or ‘in the field’. This is important because researchers are now seeing ‘synergistic effects’ of pesticides, their impacts being altered or even multiplied when they work in combination with other pesticides.
And crops are now drenched in a ‘cocktail’ of herbicides, insecticides, and fungicides: 500 are licenced for use in the EU alone.
Global insect declines
Insect populations globally are in massive decline, and their rate of extinction is eight times faster than that of mammals, birds and reptiles. While the consequences of removing vast numbers of insects are not yet properly understood, they do make up a critically important part of the diet of many birds, fish and small mammals across the planet and are vital in breaking down waste. It’s the loss of pollinators (which includes honeybees, moths, hoverflies and a host of other invertebrates) that has generated the most concern though.
Honeybees have been particularly badly hit, posing a serious threat to a wide variety of plants critical to human well-being and livelihoods. We reported recently that “beekeepers reported mass die-offs of entire hives in four Brazilian states between October 2018 and March 2019. A study by scientists at the National Agricultural Laboratory of Rio Grande do Sul released last month found five types of pesticides in dead bees, honey, young, and combs”.
A 2017 report concluded that most honeys sampled from around the world between 2012 and 2016 contained neonicotinoids at levels known to be neuroactive in bees. Recent tests have found as many as thirty different pesticides in honey samples.
Studies on bees and other insects are now discovering that insecticides not only kill them outright, but also have what are known as sub-lethal effects which can impair their development and behavior.
A report published in 2017, for example, on the sub-lethal effects of insecticides concluded that they “may cause biological effects, disturbing the number of eggs, oviposition period, larval and pupal weight, development period, adult emergency, longevity and fertility; behavioral effects on feeding, oviposition, locomotor system and reducing or increasing the production and response to pheromones; and physiological effects upon reproductive and immune systems as well as upon the nutritional status of insects.”
How might translate to real-world situations?
Having evolved in a world where insecticides were naturally produced only by certain plants, honeybees possess fewer genes for detoxification than many other insects. And pesticides can affect a bees ability to navigate (crucial to finding the hive and banks of flowers of course). They have also been found to become hyperactive, burning through energy supplies – or apathetic, unable to collect food or protect the colony. A recent Nature study found greatly diminished reproductive success in solitary bees in treated fields, and bumblebee hives in treated fields showed slower growth and produced fewer queens than hives in untreated fields.
There is no doubt that the EU’s decision should have been taken years ago based on the ‘precautionary principle’ which aims “at ensuring a higher level of environmental protection through preventative decision-taking in the case of risk”, but industry lobbyists worked very hard and spent huge amounts of money to allow the use of products that are wiping out insects. In this case at least they were defeated by science, activists, and evidence.
We can turn policy failures around by learning about the problems and getting involved. And never giving up.
- In the meantime please listen to a podcast with Professor Dave Goulson recorded in September this year which looks at the use of pesticides (especially in the UK) and where some of the statistics used in this article came from.