Scientists have linked both the collapse of bee populations and the stunning decline in bird and bat numbers to a new generation of insecticides called neonicotinoids.
It gets worse: these widely-used nerve poisons are also considered the main cause of a general collapse of insect life since the mid 1990s. Bug-spattered windshields have become rare where they were once common in North America and Europe.
One result is that insect-eating birds are starving, especially their young. In a new study published in the science journal Nature, Dutch researchers linked the steady decline of warblers, skylarks, sparrows, and starlings and other birds to the introduction of imidacloprid, the most commonly used neonicotinoid, in the late 1990s. Regions with the heaviest levels of this nerve poison in soil and water had the biggest declines in bird numbers that eat and rely on insects during the breeding season.
“It’s the new DDT but different,” said Ole Hendrickson, a former scientist at Environment Canada and member of the Task Force on Systemic Pesticides that did an exhaustive examination of every scientific study on these insecticides – more than 800 in all. The task force is a group of 50 independent scientists from more than a dozen countries.
“Instead of wiping out the top of the food chain, killing hawks and eagles as DDT did, neonics are wiping out the bottom of the food chain,” says Hendrickson. “Harvard biologist E.O. Wilson once said if we wipe out the world’s insects, we will soon follow them to extinction.”
They Are Everywhere
Neonicotinoids are used everywhere: in homes, gardens, farms, greenhouses, orchards, parks, and forests. They’re in flea and tick control for pets, in lawn and garden products and, shockingly, ornamental plants, including “bee-friendly” plants, sold at garden centres.
In June, a Friends of the Earth Canada study showed that over half of ‘bee-friendly’ home garden plants sold in garden centres have been pre-treated with neonicotinoid pesticides. The Gardeners Beware 2014 report revealed that some flowers contained levels high enough to kill bees outright. They also have sub-lethal neurological affects on bees which impacts their behaviour and health.
Imidacloprid was first used in eastern Canada in 1995 to control the Colorado potato beetle. Today if a product says it will kill insects there’s a good chance it contains one of seven neonicotinoids: acetamiprid, clothianidin, imidacloprid, nitenpyram, nithiazine, thiacloprid and thiamethoxam. They’re found in products with trade names like Admire, Gaucho, Merit, and Aloft. (A list of products containing neonicotinoids can be found on the website for the US Center for Food Safety, www.centerforfoodsafety.org)
Most crops grown in Canada and the US contain neonicotinoids. Contain means every part of a corn, soy, wheat or potato plant contains the nerve toxin. Neonicotinoids are used to coat seeds or applied to the soil. As crops grow, they incorporate the toxin making them poisonous to any insect that nibbles on them anywhere, including roots, pollen, nectar, sap and even dead leaves. They’re also in the food we eat and often in the water we drink.
These insecticides are “5,000 to 10,000 times more toxic than DDT,” said Task Force member Jean-Marc Bonmatin of The National Centre for Scientific Research in France.
If a bird eats a couple of treated seeds it will likely die.
Only 5% of the neonicotinoid on a treated seed ends up in the plant, according to another report in Nature. Approximately 1% is blown away as dust during planting, leaving all the rest in the soil and soil water where the chemical accumulates and readily washes into waterways.
The first extensive study looking at the impact on rivers and streams in the US mid-west was published in July. All rivers and streams tested were contaminated. Imidacloprid is known to be toxic to aquatic organisms in incredibly small amounts of just 10 nanograms per litre. That’s like 10 drops of detergent in enough dishwater to fill a string of railroad tank cars ten miles long. It was found in rivers at concentrations of 42.7 nano grams per litre.
Neonicotinoids move readily in water run-off both on the surface and below ground and are taken up by roots of plants in hedgerows or woods near farm fields or other areas where they’re used. This makes all kinds of plants and even trees toxic to any insect that eats it. These toxins can remain active in soils for years and accumulate.
“They’re [neonicotinoids] dangerous and probably should be banned,” said Bonmatin. However, the official position of the Task Force is to ask governments to restrict their use.
The loss of honey bee colonies known as colony collapse disorder (CCD) is widespread wherever there is heavy use of neonicotinoids.
“There is no question that neonics [neonicotinoids] are behind colony collapse disorder,” said Chensheng (Alex) Lu, associate professor of environmental exposure biology at Harvard School of Public Health. Lu has conducted studies showing that bees exposed to low doses of the nerve poison resulted in less than half of colonies surviving the winter.
Ontario and Quebec are considering restrictions following recent years where beekeepers have lost 50 to 70% of their hives. Nearly 60% of hives did not survive this year’s winter in Ontario reducing yields of a wide number of crops. When it comes to our food, one bite in three is the result of the efforts of bees and other insect pollinators.
Ontario has proposed a requirement that growers obtain a license to apply neonicotinoids, possibly for 2015. The pesticide industry is strongly lobbying against any action.
Europe placed a two-year moratorium on use of two neonicotinoids in April 2013, because of the impact on bees. The US and Canada are currently reviewing the chemicals to determine if any restrictions are needed. In August Canadian environmental groups called on the federal and provincial governments to ban them based on the results of the Task Force on Systemic Pesticides.
“Neonicotinoids persist for a long time in soil and leach and end up in our waterways. We are concerned about their large-scale use and impacts on human health and ecosystems,” said Sidney Ribaux, executive director of Équiterre, a Quebec-based environmental group.
Health Canada’s Pest Management Regulatory Agency (PMRA) acknowledges there are impacts on bees and asked farmers to use safer seed planting methods, mainly reducing “seed dust” which releases 1% of the insecticide. It is continuing to review these chemicals and may take further action. PMRA noted that 89% of Canadians who commented support a ban. An interim report will be issued in 2015, with a final report due in 2016 or 2017.
“PMRA is only looking at the impacts on bee health. That’s not what we’re really concerned about with these insecticides,” said Task Force member Hendrickson.
The Task Force’s studies show that bees aren’t the hardest hit. It is other insects, especially those that live in or near the soil, as well as valuable species like earthworms. The impacts on human health aren’t known because there have been very few studies, he said.
Stephen Leahy is an independent environmental journalist.