Neonicotinoids are already known as a major cause of the decline of bees and other pollinators.
These pesticides can be applied to the seeds of crops, and they remain in the plant as it grows, killing the insects which eat it.
The quantities required to destroy insect life are astonishingly small: by volume these poisons are 10,000 times as powerful as DDT.
When honeybees are exposed to just 5 nanogrammes of neonicotinoids, half of them will die.
It is only now, when neonicotinoids are already the world’s most widely deployed insecticides, that we are beginning to understand how extensive their impacts are.
Only a tiny proportion of the neonicotinoids that farmers use enter the pollen or nectar of the flower.
Some of the residue blows off as dust, which is likely to wreak havoc among the populations of many species of insects in hedgerows and surrounding habitats.
But the great majority – Prof Dave Goulson says “typically more than 90%” – of the pesticide applied to the seeds enters the soil.
Neonicotinoids are highly persistent chemicals, lasting (according to the few studies published so far) for up to 19 years in the soil. Because they are persistent, they are likely to accumulate: with every year of application the soil will become more toxic.
Of course, not all the neonicotinoids entering the soil stay there. Some are washed out, whereupon they end up in groundwater or in the rivers. What happens there? Who knows?
Neonicotinoids are not even listed among the substances that must be monitored under the EU’s water framework directive.
One study shows that at concentrations no greater than the limits set by the EU, the neonicotinoids entering river systems wipe out half the invertebrate species you would expect to find in the water. That’s another way of saying erasing much of the foodweb.
The people who should be defending the natural world have conspired with the manufacturers of wide-spectrum biocides to permit levels of destruction which we can only guess. In doing so they appear to be engineering another silent spring.