Pesticides and High Fructose Corn Syrup Recreate "Classic" Colony Collapse Disorder in Experiments

BotheredByBees/CC BY 2.0

This is getting silly.

While pesticide maker Bayer CropScience may keep denying it, the evidence keeps mounting up that imidacloprid, a neonicotinoid pesticide, is having a massive influence on the plight of our honeybees.

From researchers in Indiana finding a clear link between bee deaths and neonicotinoid exposure in agricultural settings through recent studies showing that minute doses of insecticides lead to increased vulnerability to parasites, the headlines have not been looking good for the pesticide industry. Just last week we saw two studies published showing non-lethal doses of neonicotinoids disrupting bees navigational behavior and ability to reproduce.

So we should take very seriously the news, reported over at mongabay, that Harvard researchers have literally recreated classic cases of Colony Collapse Disorder by treating bees with minute doses of Bayer's imidacloprid:

Past research has shown that neonicotinoid pesticides, which target insects' central nervous system, do not instantly kill bees. However, to test the effect of even small amounts of these pesticides on western honeybees (Apis mellifera), Harvard researchers treated 16 hives with different levels of imidacloprid, leaving four hives untreated. After 12 weeks, the bees in all twenty hives—treated and untreated—were alive, though those treated with the highest does of imidacloprid appeared weaker. But by 23 weeks everything had changed: 15 out of the 16 hives (94 percent) treated with imidacloprid underwent classic Colony Collapse Disorder: hives were largely empty with only a few young bees surviving. The adults had simply vanished. The hives that received the highest doses of imidacloprid collapsed first. Meanwhile the five untreated hives were healthy.

While authors of previous studies have been cautious about drawing too many conclusions, suggesting that insecticides may be a contributing factor alongside habitat loss, climate change etc—lead author Chensheng (Alex) Lu was more unequivocal, stating that there is clear evidence that imidacloprid and other neonicotinoids are the likely "culprit for Colony Collapse Disorder".

Interestingly, the study also suggests that one of the ways bees are being exposed to imidacloprid may be through high fructose corn syrup which beekeepers have been feeding their colonies for years. U.S. corn began to be sprayed with imidacloprid in 2004-2005, just around the same time that CCD appeared on the scene.

Whether or not this is the smoking gun, or just one more pointer to neonicotinoids as part of a larger problem, the case for a ban on imidacloprid and other neonicotinoids is mounting with every new headline. Bayer can continue to fund all the bee care centers it likes, but the calls for a neonicotinoid ban will just keep growing louder.

Tags: Agriculture | Bees | Colony Collapse Disorder | Insects | United States