Those who are still skeptical about the role neonicotinoid pesticides are playing in the worldwide devastation of honeybee populations, need only look to what happened in the spring of 2013 in Ontario, Canada: Within days of the planting of nearby fields of GM (genetically modified) corn, beekeepers saw their honeybees die off in droves.
“Once the corn started to get planted our bees died by the millions,” beekeeper Dave Schuit said. Schuit alone lost about 600 hives, totaling roughly 37 million bees.
Ninety-four percent of GMO seeds are pre-treated with neonicotinoid pesticides. These chemicals, known as “systemic” pesticides, are then absorbed by the growing plant into all of its tissues. This makes the leaves toxic to agricultural pests, but also makes the pollen, nectar, flowers – and yes, seeds – toxic to any other animals that might come into contact with the plant, from honeybees to birds, to human consumers.
Beekeepers immediately blamed neonicotinoids for the bee deaths, which occurred so quickly after planting that it was unlikely the GMO seed itself could have killed the insects. Instead, beekeepers have pointed the finger at a practice known as “air seeding,” which can cause neonicotinoid dust to fly up off seeds during planting and into the surrounding air. This dust can then drift widely.
This explanation was supported by two separate investigations into the incident. One, by researchers from Purdue University, found that dead and dying bees from the area showed neurotoxic symptoms consistent with neonicotinoid poisoning, and that all of them carried traces of one of two such chemicals. They identified seeds from local agricultural fields as ” the only major source of these compounds.”
Another study, by the local Pest Management Regulatory Agency, was even more blunt, stating directly that neonicotinoid-treated corn seed “contributed to the majority of bee mortalities.”
Chemicals also destroy bees’ immune systems
New research continues to implicate neonicotinoids in the ongoing honeybee population crash, which pesticide companies have instead tried to blame on disease or pests. Yet, according to a recent study from the Proceedings of the National Academy of Sciences, neonicotinoids are not just neurotoxins, but also damage the immune systems of bees – thereby making them more vulnerable to the very pathogens that the pesticide industry points at to exonerate its products.
The study, conducted by researchers from the University of Udine, Italy, found that when bees who had been exposed to neonicotinoids were later infected with the normally harmless pathogen, deformed wing virus, their immune systems were so compromised that the virus was often fatal.
The damage to the immune system seems to occur as a result of the nerve damage caused by neonicotinoids.
“Our data indicate the possible occurrence in insects, as in vertebrates, of a neural modulation of the immune response,” research member Francesco Nazzi said. “This sets the stage for future studies in this research area, and poses the question on how neurotoxic substances may affect the immune response.”
Loss of the wild habitat that bees and other pollinators use for foraging is also believed to be a major factor in crashing populations. Malnutrition also increases bees’ vulnerability to disease and toxic chemicals.
Two major reviews published in 2015 also warned that the effects of neonicotinoids go far beyond honeybees, or even pollinators. One, published in the journal Nature, showed that neonicotinoids are devastating bird populations, both through direct poisoning and through elimination of food sources. The other, a review of 800 prior studies conducted by the Task Force on Systemic Pesticides, found that neonicotinoids are causing destruction to populations of “non-target” animals, including harmless and beneficial insects, earthworms, aquatic invertebrates, lizards and even fish.
The damage being caused by neonicotinoids has been compared to the wide-reaching ecological devastation once caused by DDT.
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