Supposedly Inert Agrochemicals Impair Learning in Honey Bees

Honey bees exposed to agrochemicals used on farms may develop learning impairments that prevent them from being able to forage or even find their way back to the hive, say researchers at Penn State’s College of Ag Sciences.

Courtesy Maryann Frazier, Penn State

Former entomology graduate student LTJG Tim Ciarlo, U.S. Navy, professors of entomology Chris Mullin and Jim Frazier, and graduate research assistant Dan Schmehl recently published their research in PLoS ONE, an online open-access journal for the communication of all peer-reviewed scientific and medical research.

According to their research, pesticide spray adjuvants could be contributing to Colony Collapse Disorder (CCD), which continues to threaten honey populations since its emergence in 2006. “Previously, active ingredients has been the focus of pesticide-driven CCD research, but not much attention has been placed on the other agrochemicals that are used in addition to and in combination with them,” says Ciarlo, whose research work became the focus of his master’s thesis.

These other agrochemicals are classified as ‘inert ingredients” and include spray adjuvants that are either included in the pesticide formulations or tank-mixed and sprayed along with the pesticides. Adjuvants are designed to boost the efficacy of active ingredients and are largely assumed to be inert; therefore they are not usually included in risk assessment trials required to register a pesticide or its formulations. Additionally, the specific ingredients that make up spray adjuvants are considered trade secrets of the chemical companies that manufacture them and are not included on the label. “This is the first time the impact of spray adjuvants on honey bee behavior has been studied,” Ciarlo explains.  Read More...