Although it’s obvious that something is killing bees in mass quantities, for years scientists have struggled to finger a culprit. A continued mass die-off of honey bees would be disastrous for our food system, so investigations into possible causes have become more urgent. A new study published just days ago claims that a toxic cocktail of pesticides and fungicides has contaminated the pollen that bees collect and bring back to the hive. Bees affected by chemical combination demonstrated a dramatically diminished ability to fight off parasitic invasion, which eventually proves fatal.
To arrive at this conclusion, researchers from the University of Maryland and the US Department of Agriculture collected pollen from east coast hives responsible for pollinating cranberry, watermelon and other crops. When they fed the pollen to otherwise healthy bees, they noted a significant decline in their ability to resist infection by a parasite called Nosema ceranae, which has often been suggested as a cause for Colony Collapse Disorder.
The report made no claim that the parasite is causing CCD (in which entire hives perish at onces) but it did point out that, on average, collected pollen was contaminated with nine different pesticides and fungicides. “Most disturbing, bees that ate pollen contaminated with fungicides were three times as likely to be infected by the parasite,” reports Quartz. “Widely used, fungicides had been thought to be harmless for bees as they’re designed to kill fungus, not insects, on crops like apples.”
“The pesticide issue in itself is much more complex than we have been led to believe,” Dennis vanEngelsdorp, the study’s lead author, told Quartz. “It’s a lot more complicated than just one product, which means of course the solution does not lie in just banning one class of product.”