Honeybees and toxic GM seeds

February 2012

Furry Bee
Bee on clover. Photo by Guerito on Flickr
Honeybee populations have been in serious decline for years: not just a few deaths here and there, but total annihilation of entire colonies. Many possible causes have been put forward, but none has been able to explain the huge scale of the collapse.

The most rational explanation, as one insect specialist recently described it is that the modern world is subjecting bees to “death by a thousand cuts”. These cuts range from disorientation induced by mobile phone masts, to parasitic and other diseases, to chemical poisoning. Whereas the mobile phone masts are localised and stay that way, and treatments for identified pathogens can be developed, chemicals are another matter: they are ubiquitous, mobile, infinitely varied, and toxicologically interactive.

Amidst the rising concern about the extent of chemical contamination of our environment, one of the most frequently touted benefits of GM crops is that they reduce chemical pesticide use. This is good PR used to present major commodity crops such as corn into a 'green' option.

In reality, these crops only produce artificial 'Bt' insecticides against a limited number of pests. The remaining insects which attack the crops are not well controlled by Bt. To overcome this, and perpetuate the myth the Bt crops use less pesticide treatments, virtually all corn seed is now doused in 'neonicotinoids', synthetic derivatives of nicotine which kill insects by attacking the nervous system.

The 'life cycle' of neonicotenoids is certainly not an environmentally friendly one.

Virtually all corn and about half of all soya seed are coated with neonicotenoids. The chemical is sticky and so, to keep the seeds flowing freely in the planters, they are mixed with talc. During subsequent planting and cleaning of the planter, large amounts of light, mobile and neonicotenoid-contaminated talc is blown into the air.

After planting, the seed-coating travels both outward from the plant through the soil where it can persist for up to two years, and inwards into the plant where it spreads systemically while the plant grows, ending up everywhere including the leaves, pollen and nectar. From the soil and air, neonicotenoids can end up contaminating adjacent fields and wild flowers. There's obviously plenty of scope for bees and other beneficial insects to come into contact with the poison.

No one disputes that neonicotinoids are toxic to bees. However, the assumptions used by agri-chemical manufacturers to convince regulators that the insects can't possibly be exposed to concentrations high enough to be harmful is only now being revealed as baseless.

A team of entomologists in America took some meaningful measurements over two years (2010-2011) in Indiana, and presented some very uncomfortable facts:
  • Neonicotinoid levels in exhaust talc were 700,000 times the acutely lethal contact dose for a bee. At this concentration, even small amounts landing on flowers visited by bees can kill foragers or be transported back to the hive in contaminated pollen.
  • Industry claims of no harm are based on the amount shown to kill the bee: the reality is that sub-lethal doses of a nerve-damaging toxin can kill indirectly by, for example, disturbing the behaviour needed to survive, or by making the insects more susceptible to pathogens and parasites.
  • Industry claims that bees don't forage much on corn pollen are wrong (this myth may have seemed plausible because maize flowers are pollinated by wind, not by insects). In fact as the scientific observation showed “maize pollen was frequently collected by foraging honey bees while it was available: maize pollen comprised over 50% of the pollen collected by bees, by volume, in 10 of 20 samples”.
  • Industry insistence that little if any neonicotinoid-laced material actually makes it into beehives appears to be another baseless assumption. The scientists found the toxin in all of the dead bees they collected near hive entrances during the spring. Surviving bees were seen to exhibit signs of insecticide poisoning, such as tremors, uncoordinated movements and convulsions. Neonicotinoids were also found in the pollen collected by the bees and stored in the hive.

The cocktail effects of neonicotinoids plus the hundreds of other toxic agri-chemicals to which bees foraging over a wide area will be exposed have not been studied.

An additional uncomfortable point is that the US agency which licenses pesticides relied on industry-funded research. A leaked document has indicated that the company's own scientists consider the research to be shoddy.

The conclusion can only be that there may have been a change in pesticide use resulting from GM crops, but it is not a reduction: rather, there has been a shifting of the chemical-load to other part of the system. Prior to the commercialisation of Bt crops, most corn went untreated by insecticides: when maize crops were rotated with soya, only 5 to 10 per cent was sprayed for corn-borers. Now, 100% of corn must be laced with pest-controlling chemicals throughout its existence.

Plant-pathologist Doug Gurian-Sherman points out the bottom-line:
“In healthy agro-ecosystems, there is usually limited need for these types of pest control, and in most cases, that need can be met through breeding at much less expense than GE .”


Never forget that, although corn does not require insect pollinators, most plants which provide our food do. The yield of many large-scale cropping systems depends on hives of honeybees transported into the area, and the production of most fruit, nut and vegetable crops need insect pollinators. GM plants which 'reduce chemical pesticides' could reduce humanity to famine.

Bees can't organise political campaigns to protect themselves, and beekeepers don't have the cash or clout to wield the necessary influence. Both are up against a chemical industry which reeled in $1 billion in 2010 from the sales of two new neonicotinoid products, and saw the sales of these products jump 28% in the last quarter of 2011 compared with the same period the previous year. The US administration has shown itself to have little appetite for tangling with the agri-chemical businesses.

All this means it's up to YOU. A good place to start shouting is at your MP and MEPs to banish neonicotinoids from your food chain and from your environment. Sadly, your survival may depend on it.

  • Doug Gurian-Sherman, Genetically Engineered Crops in the Real World - Bt Corn, insecticide Use, and Honey Bees, Union of concerned Scientists, 10.01.12
  • Brian Wallheimer, Purdue Researchers Greg Hunt and Christian Krupke: Honeybee deaths linked to seed insecticide exposure, Purdue Today, 11.01.12

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