The neonicotinoids are insecticides developed with the hope of being less harmful to wildlife and beneficial insects than the available insect killers, the pyrethroids and organophosphates. The neonicotinoids came into widespread use with the understanding that they would not kill beneficial insects like the honey bee and bumblebee. The use of neonicotinoids coincides with the die-off of honey bees and significant reductions in bumblebees. Two studies linking honey bees’ having difficulty in navigating from flowers to the hive confirm that neonicotinoids impair bees’ senses. The studies are reported by The Washington Post at http://www.washingtonpost.com/national/health-science/new-bee-research-details-harm-from-insecticide/2012/03/29/gIQAZrnGjS_story.html. The studies find that bee hives exposed to low levels of neonicotinoid insecticides have fewer bees and bumble bees produce markedly fewer queens. Bayer CropScience, a manufacturer of neonicotinoids, calls the studies inconsistent with their findings. Beekeepers and the Center for Food Safety petitioned the Environmental Protection Agency to ban the use of clothianidin that the EPA approved using Bayer’s tests.
Neonicotinoids are generally applied as a seed coating. The systemic action of the insecticide causes the poison to be distributed throughout the plant including the nectar and pollen, highly attractive bee foods. Traces of neonicotinoids are taken back to the bee hive by foraging bees. While beekeepers in the United States are taking annual honey bee colony losses of one third each year, the effects are often more subtle than total colony failures. Colonies are often described as simply not thriving. Bee populations may be low; bees may have shortened life expectancies; or hives may lack sufficient bees of appropriate foraging age. Each of these situations leads to colonies that are susceptible to diseases and parasites. With small populations, colonies don’t produce surpluses of honey. Bee hives used for pollination service fail when graded according to bee population. With the ever increasing use of neonicotinoid insecticides that have been shown to have a detrimental effect on pollinators, the crops, lawns, and golf courses flourish while honey bee colonies, native bees, and beneficial insects quietly disappear.--Richard