For those who follow environmental or agricultural science, concern over pollination is nothing new. The sudden and unexpected death of honeybee colonies, in a phenomenon called Colony Collapse Disorder (CCD), has been documented for many years now and a wide range of factors, including viruses, mites, insecticides and electromagnetic radiation have all been suggested as the cause. Recent research has focused largely on a class of agricultural insecticides called neonicotinoids.
Coming from the same chemical family as nicotine, the psychoactive ingredient in tobacco, neonicotinoids were introduced in the 1990’s as a pesticide alternative that was less harmful to vertebrates than the more traditional organophosphates. Neonicotinoids specifically target receptors that are present in insect nervous systems but not in most vertebrates, giving them highly specific toxicity. Neonicotinoids are often absorbed by plants and distributed throughout the plant’s tissues as it grows. This means that the insecticide could be applied to the soil around seedlings and would protect the entire plant as it grew, without requiring repeated sprayings to cover new leaves. All these characteristics are legitimately beneficial, both to growers and the environment, when compared with previous generations of pesticides.
The problem arises from their persistence in natural environments. Neonicotinoids break down very slowly in the natural environment and many of the compounds that result from their biodegradation are just as toxic, if not more so, than the original compound. Bees find themselves exposed to these compounds through the pollen and nectar they eat, suspended dust, surface water and the materials they use to make their hive. Recent research finds that bees can suffer harm when exposed to sub-lethal doses over a long period of time and this phenomenon is thought to contribute to CCD.
The article which is linked to this post is a good, clearly and articulately written review of the literature on neonicotinoids and bees. Let me be clear, I am neither an entomologist nor an environmental toxicologist, so I cannot personally vouch for the conclusions of the article. It is, however, published in a reputable journal and is exhaustively cites other academic studies to support its conclusions.
Given the immense harms that humanity stands to suffer if pollination services are lost, we may soon approach a point where some sort of aggressive policy action may have to be taken, even if the cause of CCD is not known with complete certainty. Losing neonicotinoids as an insecticide will surely cause economic harm and likely will cause environmental harm as well (as older, more toxic substitutes are employed). This may be a necessary sacrifice for the sake of our agricultural system and further research on this subject is critical.