Some of you may recall the excellent bee reporting Tom Philpott did for Grist last year. Here he is again interpreting the Purdue study for Mother Jones.
No one disputes that neonics are highly toxic to bees. But Bayer insists—and so far, the EPA concurs—that little if any neonic-laced pollen actually makes it into beehives, and that exposure to tiny amounts has no discernible effect on hive health. Bayer also claims that bees don’t forage much on corn pollen.
The Purdue study calls all of this into question. The researchers looked at beehives near corn fields and found that bees are “exposed to these compounds [neonics] and several other agricultural pesticides in several ways throughout the foraging period.” Contradicting Bayer’s claim that bees don’t forage much in cornfields, they found that “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.” They detected “extremely high” levels of Bayer’s clothianidin in the fumes that rise up when farmers plant corn seed in the spring. They found it in the soil of fields planted with treated seed—and also in adjacent fields that hadn’t been recently planted. And they found it in dandelion weeds growing near cornfields—suggesting that the weeds might be taking it up from the soil.
Most alarmingly of all, they found it in dead bees “collected near hive entrances during the spring sampling period,” as well as in “pollen collected by bees and stored in the hive.”