Interesting article from Mother Earth News about the effect of imidacloprid insecticides in honeybees. Aren’t Merit and Marathon imidacloprid insecticides?

"Colony collapse disorder has wreaked havoc on U.S. beekeeping businesses (and the agriculture industry) since its devastating arrival in 2006. The veiled killer entered hives across Japan for the first time earlier this year, affecting 25 percent of the national beekeeping association members. Now the U.S. Environmental Protection Agency (EPA) is being sued by the nonprofit Natural Resources Defense Council (NRDC) for withholding details about the impact of neonicotinoids — a class of widely used pesticides — on honeybees and other pollinators.
The EPA identifies two specific neonicotinoids,imidacloprid and clothianidin, as highly toxic to bees. Both chemicals cause symptoms in bees such as memory loss, navigation disruption, paralysis and death.

Both chemicals have been linked in dramatic honeybee deaths and subsequent suspensions of their use in France and Germany. Several European countries have already suspended them. Last year Slovenia and Italy also suspended their use for what they consider a significant risk to honeybee populations.

While Bayer CropScience, the primary producer of both pesticides, maintains honeybee deaths reported in Europe were caused by unusual application errors, they don’t dispute the proven toxicity of their products. Instead, they maintain bees do not encounter enough of an exposure to cause harm. Now even that assertion is under the microscope.

A report by Maryann Frazier, senior extension associate at Pennsylvania State University, points to a new study from Italy suggests honeybees may be ingesting neonicotinoids at levels 1,000 times higher than that in pollen or nectar via water droplets expressed from the leaves of corn grown from the pesticide-coated seed. This “guttation water” is a common source of liquid for forager bees. The concentrations in the droplets were high enough to kill bees within five minutes of consumption.

Frazier also highlights a study from North Carolina University that found the neonicotinoid Terraguard and the fungicide Procure had synergistic affects when combined, increasing the danger of the neonicotinoid to honeybees to over 1,000 times its original toxicity. The researchers at Penn State are concerned that even sub-lethal doses of these pesticides, while not killing the bees, are impairing their behavior and suppressing their immune systems.

“Their use has increased dramatically over the past few years and they are now the most widely used group of insecticides in the United States,” writes Frazier."

There are many good resources online about Colony Collapse Disorder of honeybees, but a good summary can be found on Wikipedia:

http://en.wikipedia.org/wiki/Colony_Collapse_Disorder

The article notes that a major Penn State study showed that the only common factor in ALL reported cases of CCD is malnutrition/drought, and while there may be various other factors at work in different cases (especially pathogens), poor nutritional condition of the hive populations is most likely the main cause.

Interiorscapers obviously would not be a factor in contributing to this problem, since we apply imidacloprid indoors where bees will not come into contact with the product of with plants treated with it.

"Greens", especially those of the European persuasion, never miss an opportunity to blame some new phenomenon on human-related factors. That gets plenty of play in the media when it is first brought out, but unfortunately, the ultimate truth does not.

Clem

Normally I avoid controversial posts like the plague, but being married to a Beekeeper I have to jump in. The only thing that scientists can say for sure is that they do not know what the cause of colony collapse is and are examining every potential influence.The worker bees leave the hive never to return with the pollen and nectar needed to feed the hive,so malnutrition would be a secondary effect of this event.

Karen

I will defer to Karen, since she has first-hand experience that I don’t. As a biologist by training, I do know that it’s sometimes difficult to distinguish primary phenomena from secondary ones, especially with organisms that are difficult to study intensively in their natural habitats. So Karen makes a good point, and what we are looking at is possibly a classic chicken-and-egg situation, where we don’t know whether the malnutrition is responsible for the occurrence of CCD, or the reverse is true.

Not to hijack this thread, but it brings to mind the global warming debate...human-mediated climate change advocates postulate that the increase in CO2 from manmade sources is responsible for the increased average global temperatures at ground level that are reported by many sources; skeptics point to data that shows that historically, virtually all global warming periods have PRECEDED increases in atmospheric CO2 levels, leading scientists in the past to conclude logically that increased plant, microbiological and animal metabolic activity is a RESULT OF increased temperatures, which leads to a resulting increase in the level of CO2 in the atmosphere (this data comes from pre-industrial times and so human intervention cannot be responsible for the observed trends). So which came first? The CO2 or the warming?

If you look at current climate trends on several of the other planets in our solar system, especially Mars, they are warming at about the same rate as the Earth (Mars’ polar ice caps are mimicking the melting reported in our arctic and antarctic caps, yet there are no cars or power plants on Mars, to my knowledge). So is the Earth warming primarily because of human activities, or because, like Mars, it is currently in a natural cosmic cycle where it is receiving additional solar heating? If you think about it for about ten seconds, the answer seems pretty obvious.

Clem

Here is a link to the Penn State FAQ for CCD:

http://maarec.cas.psu.edu/FAQ/FAQCCD.pdf

It summarizes the phenomenon and reports of its symptoms and other conditions surrounding its occurrence in hives maintained both for contract pollination and for honey production, and also excludes some theorized causal agents while listing some likely areas for further research of CCD.

One interesting possibility is lack of genetic diversity of the honeybee populations (i.e., lack of "hybrid vigor" due to excessive inbreeding of bees bred and raised for sale to beekeepers); another is nutritional unfitness of adult bees that may lead to their failure to perform their work of collecting food for the hive. And another item noted is that CCD or CCD-like outbreaks have occurred prior to the use of neonicotinoid pesticides by farmers (sound familiar?), so we shall have to wait for some more definitive answers from researchers, but the consensus seems to be that a complex of factors is at work here.

Clem