Until recently, the evidence was inconclusive on the cause of the mysterious “colony collapse disorder” (CCD) that threatens the future of beekeeping worldwide. But three new studies point an accusing finger at a culprit that many have suspected all along, a class of pesticides known as neonicotinoids.

In the U.S. alone, these pesticides, produced primarily by the German chemical giant Bayer and known as “neonics” for short, coat a massive 142 million acres of corn, wheat, soy and cotton seeds. They are also a common ingredient in home gardening products.

Research published last month in the prestigious journal Science shows that neonics are absorbed by the plants’ vascular system and contaminate the pollen and nectar that bees encounter on their rounds. They are a nerve poison that disorient their insect victims and appear to damage the homing ability of bees, which may help to account for their mysterious failure to make it back to the hive.

Another study published in the American Chemical Society’s Environmental Science and Technology journal implicated neonic-containing dust released into the air at planting time with “lethal effects compatible with colony losses phenomena observed by beekeepers.”

Purdue University entomologists observed bees at infected hives exhibiting tremors, uncoordinated movement and convulsions, all signs of acute insecticide poisoning. And yet another study conducted by scientists at the Harvard School of Public Health actually re-created colony collapse disorder in several honeybee hives simply by administering small doses of a popular neonic, imidacloprid.

Every spring millions of bee colonies are trucked to the Central Valley of California and other agricultural areas to replace the wild pollinators, which have all but disappeared in many parts of the country. These bees are routinely fed high-fructose corn syrup instead of their own nutritious honey. And in an effort to boost productivity, the queens are now artificially inseminated, which has led to a disturbing decline in bee genetic diversity. Bees are also dusted with chemical poisons to control mites and other pathogens that have flourished in the overcrowded commercial colonies.

Still, this is a disaster that does not need to happen. Germany and France have already banned pesticides that have been implicated in the deaths of bees. There is still time to save the bees by working with nature rather than against it, according to environmentalist and author Bill McKibben:

“Past a certain point, we can’t make nature conform to our industrial model. The collapse of beehives is a warning – and the cleverness of a few beekeepers in figuring out how to work with bees not as masters but as partners offers a clear-eyed kind of hope for many of our ecological dilemmas.”