Over the past few decades, honeybees (primarily in the US but also elsewhere) have been threatened by a suite of hazards, including Varroa destructor (a parasitic mite), which carries two deadly bee viruses (one of them you may recognize as the “Israeli acute paralysis virus” or IAPV), and many other pathogens (including more than 20 other viruses). These hazards, in combination, have led to a syndrome known as CCD or colony collapse disorder. In the US, losses have been as high as 50% over a single winter, with some sources saying that there has be a 70% decline over the past decade. Although the actual numbers are in dispute (especially regarding the precise definition of CCD), the point still stands that honeybees are much less reliable than they used to be.
But honeybees have always had a lot of pests, why the sudden decline? As usual, the answer is complicated. Although the pathogens are the proximate cause of the declines, the ultimate cause is a reduction in the health and immune defenses of the honeybees. Which has recently been convincingly tied to pesticide use.
Recent research has been pointing more and more to pesticide usage as the ultimate cause of honeybee declines. The US Department of Agriculture has shown negative effects of the components of pesticides (especially neonicotinoids ) that leave residues in floral nectar and dew (which honeybees drink).
Yesterday, I was at a symposium on pollinators and there were a lot of alarming talks discussing the ways that pesticides affect honeybees (including changes in behaviour, physiology, and even gene expression). One of the speakers, Chris Mullin, described the effects of the inert (or “inactive”) ingredients in these pesticide formulations, which are sometimes 20 times more lethal than the active ingredient alone (see Johnson et al. 2010). The same ingredients that are in shampoos and antiperspirants!
Dr. Mullin found more than 130 different kinds of pesticides in honeybee wax and propolis. Is it any wonder that they are struggling? Even worse, we have no idea how the native bees are affected…they are much more difficult to study and Apis mellifera is not a good representative of bees that can be 1/10th of its size.
Monsanto is a company most famous for genetically engineering crops to be resistant to pesticides (specifically herbicides, specifically Round Up aka glyphosate). Founded by Norman Borlaug, who had the mission to eliminate world hunger by improving crops to increase yield and efficiency, the company not only produces the GM crops, it also sells the herbicide. Double dipping some would say.
In response to a recent outbreak in glyphosate resistant weeds, Monsanto has been trying to get permission to create genetically modified crops that are resistant to Dicamba, a much more serious broad leaf herbicide. (See Mortensen et al. 2012, in Bioscience)
People have started looking sideways at Monsanto, which is being blamed for the declines due to the fact that it is the world’s largest producer of glyphosate, which is a pesticide. The main problem is that the declines were tied to insect pesticides and not herbicides. And some people are blaming Monsanto because of its GM corn (not scientifically tied to the declines), and not because of the pesticides.
How does Monsanto respond? It buys up Beelogics, which is dedicated to the conservation of honeybees. There have been some murmurs about this. (Note that all of these articles, including the Huffington Post, confuse the term “pesticides” with the “herbicides” that Monsanto produces. The research points to neonics (specifically insecticides) while Monsanto specialises in herbicides that attack plants.)
What is next? A genetically engineered bee that is resistant to the insecticides used on apple orchards? What an interesting and yet terrifying concept!