 |
| Planting time! |
Neonicotinoids must be classified as highly toxic to honey bees. However, studies on toxicity exposure indicate that it is very unlikely that honeybees will die when the product is applied to seeds. Honeybees also rarely forage on seedling corn or soybeans. Also, it is very unlikely that commercial beehives will be negatively affected. (Marlin Rice, Professor Entomology Iowa State University, IPM.iastate.edu)
Neonicotinoids are widespread seed treatments derived from nicotine which was one of the first pesticides applied in modern agriculture. They are powerful and though on honey bees when sprayed on plants but as seed treatments, it is thought to help beneficial organisms by keeping the potent chemical on the seed.
This is how it works: A tiny amount of neonics goes all over the plants through the vascular system to nectar and pollen; generally less than 10 parts per billion. (Amount thought to be far below a dose that would kill a bee outright.)
This is how this furiously debated issue happened: In 1994, some French beekeepers were alarmed by the decline and death of many of their colonies that had been placed near fields of flowering sunflowers treated with the first neonic pesticides, Imidacloprid (Gaucho).
At the same time, miticides had been applied for many years to control the Varroa mites population in colonies. Then the mites became resistant (non-responsive) to the miticides employed at the time and Varroa became an epidemic in France that same year. This confused the issue regarding what was really killing the bees. The quick and easy answer was: but of course the pesticide applied by the sunflower grower! And it took hold in many people's mind.
To be clear, the direct impact of nicotinoids on bees is still today highly disputed among many scientist around the world, despite more than 2 decades of research.
So far this is were we are " research has not established a conclusive link between CCD and neonicotinoid seed treatments." p.67 Bee Time Lessons from the Hive , Mark L. Winston
What is absolutely CLEAR: Neonics can have sublethal effects at low dosages bee encounter while foraging on nectar and pollen like trembling motions, or memory loss; the honey bees may not be able to find their way home to their nests, decreasing the overall effectiveness of their immune system as a whole, colony level, not individual bee.
It is not known, or has yet to be definitively established that these effects (memory loss, trembling, passivity...) alone are enough to cause an entire colony to dwindle rapidly to its death.
The overall picture that seem to emerge from studies around the world:
" one of small effects on individual bees that are amplified as they accumulates in the thousands of workers that make up a colony. Each worker bees function is reduced only slightly by anyone exposure (virus, neonics) but synergistic interaction from multiple exposures to diseases, the miticides and antibiotics applied by beekeepers and agricultural pesticides collected by foraging bees lead to considerably worse outcomes than from any one factor alone." p.71 Bee Time Lessons from the Hive , Mark L. Winston
The Xerces Society for Invertebrate Conservation retiring the same thought : " No link between neonics and CCD. But may have non lethal effects on bees."
All AGREE that it is a combination of factors that cause our colonies to dwindle and later die: Parasites, pathogens, poor nutrition and pesticides.
Bee experts Dr. Marla Spivak, University of Minnesota; Dr.Zachary Huang, Michigan State University, and Randy Oliver, beekeeper and biologist think that a lack of good nutrition may be a major factor in declining bee health. (Honeybee suite.com)
Maybe the pathogens are not worst than before but the availability of good foraging plants has decreased in the last 20 years.
I hope that this topic will inspire and encourage you to read and be more knowledgeable, making your own conclusion based on facts.
No comments:
Post a Comment