Colony Collapse Disorder is probably due to a collection of factors that have been brooding over the past few decades. It's really hard to pin-point
a causal link to CCD for any of these factors.
However, insecticide use has received lots of attention from scientists, media and government agencies, and with good reason.
The possible perpetrator: NEONICOTINOIDS!
The main neonicotinoids presently on the market are imidacloprid, thiamethoxam, clothianidin, thiacloprid, dinotefuran, acetamiprid, nitenpyram and
All of these act on nicotinic acetylcholine receptors in the insect's central nervous system, where once binded to the receptor they keep it open and
allow prolonged excitation which eventually leads to convulsions, paralysis and then death. Spooky stuff.
Since the 90's, neonicotinoids have entered the pest control market as a new hope to combat the ever-resistant insects that plague our crops. Due to
the failure of DDT and pyrethroids, the chemists and companies needed something new: enter neonicotinoids. These things mimic the endogenous
neurotransmitter acetylcholine which is necessary for daily function for the insect but is readily broken down by the insect's metabolic system.
Neonicotinoids however do not get broken down. Once they bind, they bind. That was the point, to stay as long as possible in the insect to kill it.
The chemists didn't really realize how well their new miracle drug worked. Neonicotinoids last for quite a while in the environment and have a
systemic mode of action where they end up in a plant's circulatory system and eventually its pollen. Bees, which co-evolved with pollinated plants,
haven't developed a genetic resistance against this kind of toxin (unlike some species of flies, mites, thrips, beetles and moths).
Many studies have shown the acute disruptive effects of these toxins on bees' behaviour, physiology, memory and learning systems. Ah, but there is
always a second side to the coin here where other researchers have conducted various short term studies claiming that they were long term, faulty
methodology and inadequate statistical analyses. There is no doubt that neonicotinoids work well, almost too well and clearly have an adverse affect
on bees. But is it singly due to this toxin?
I don't think that it's these chemicals by themselves but they did help break through the threshold of declining bee health. I think that CCD is due
to an increase of urbanization, air pollution, inefficient farming practices, liberal dousing of insecticides and maybe some other factors that
haven't been discovered. This is such a tangled case that it's hard to determine who/what is responsible. Neonicotinoids may have allowed for CCD to
enter into the media spotlight due to it's effects but the situation is much worse. This may be just a symptom of the result of humanity's (mostly
the developed nations rather) inefficient lifestyles. It takes millions and billions of dollars (not to mention the years) for an insecticide to go
from paperwork to actual practice so there is a huge drive to keep it in market and use. Banning them won't be an easy task, and it might even be
worse because farmers will go back to older, more hazardous insecticides.
I've heard a few interesting solutions to deal with this, from hand-pollination (like they do in
) to the creation of
to pollinate. This is a global problem and it
will take global thinking.