Controversy has accompanied neonicotinoid pesticides ever since their commercial introduction in the mid-1990s. Discovered by Japanese researchers at a Bayer lab in Tokyo while working on an earlier, 1970s, pesticide created in California, it was released as imidacloprid in the 1990s. Within a decade it, along with clothianidin, also made by Bayer, and thiamethoxam from Syngenta, were accounting for 25 percent of all global insecticide sales.
Protests commenced almost as quickly, however. French apiarists blamed imidacloprid-coated sunflower seeds, introduced in 1994, for their honeybee losses. Five vears later such treated seed was banned in France.
Nevertheless, the newly-named 'neonics' were greeted with enthusiasm by farmers. Less toxic than long-used organophosphates and carbamates, neonics are less toxic to birds, mammals--and humans. Chemically similar to nicotine--hence their name--but for insects they are neuro-toxic.
Another acclaimed attribute for commercial agriculture is that neonics are systemic pesticides. Applied to the seeds of crops, they are water soluble and absorbed into the growing plant, including flowers, pollen and nectar. To some scientists though, these are alarming trends.
Improperly applied to seeds, the pesticide could be carried into surrounding areas. As a soluble, it may also pollute water draining off fields. Worse still, the neonic infected pollen and nectar may sicken and destroy the pollinators vital to many essential crops--honey bees, bumblebees, wild bees and many others.
Numerous scientific studies seem to have demonstrated these worries are based on firm fact. Or are they?
Last November, a series of papers by researchers at the University of Guelph shook investigators to the honey comb. In the Journal of Toxicology and Environmental Health-B, Keith Solomon, a toxicology and emeritus professor with the School of Environmental Sciences and adjunct professor Gladys Stephenson, analyzed 234 studies. Their conclusion? Neonics show no significant ill effects on honeybee colonies.
Yes, these pesticides can kill individual honeybees and may pose a threat to other pollinators, the researchers admit. But, says Solomon, "At least for honeybees, these products are not a major concern. Use of these neonics under good agricultural practices does not present a risk to honeybees at the level of the colony."
There lies the stinger: good agricultural practices. Neither conventional or, to be fair, organic farmers are known for always abiding by rules, regulations and recommendations.
Note also the statement may pose a risk to other pollinators. For some crops, bumblebees are known to be more efficient pollinators than honeybees. The benefits of wild bees have not been so widely researched but at least in some instances have been demonstrated to be considerable.
The internet continues to buzz angrily as agrochemical companies, farmers and environmental activists butt heads. "There is nothing I think any scientist could do at this point to make people all sit down and have any answer," bee researcher Dave Goulson told Daniel Cressy, writing in the esteemed journal Nature.
In the end it will probably fall to regulators to rule on control for the controversial chemicals. In continental Europe, the EU has already decided on wide-ranging restrictions. The United States is expected to make a decision later this year. The UK has said it will control use of neonics. As Harold MacMillan once observed, "Britain's most useful role is somewhere between a bee and a dinosaur."
Wes Porter is a horticultural consultant and writer based in Toronto. Wes has over 40 years of experience in both temperate and tropical horticulture from three continents.
Controversy has accompanied neonicotinoid pesticides ever since their commercial introduction in the mid-1990s. Discovered by Japanese researchers at a Bayer lab in Tokyo while working on an earlier, 1970s, pesticide created in California, it was released as imidacloprid in the 1990s. Within a decade it, along with clothianidin, also made by Bayer, and thiamethoxam from Syngenta, were accounting for 25 percent of all global insecticide sales.
Protests commenced almost as quickly, however. French apiarists blamed imidacloprid-coated sunflower seeds, introduced in 1994, for their honeybee losses. Five vears later such treated seed was banned in France.
