In a photo provided by Heather Mattila, honeybees in Vietnam engage in a defensive behavior called fecal spotting, which appears to ward off predatory hornets. Photograph:( Heather Mattila © 2021 The New York Times Company )
The researchers used the data expounded to quantify how combinations of those stresses affected the pollinating insects
As per a recent analysis of 90 studies, agricultural pesticides which are sold to farmers 'ready mixed' into cocktails can kill twice as many bees.
The researchers used the data expounded to quantify how combinations of those stresses affected the pollinating insects.
They say that commercial formulas, which contain multiple chemicals, should now require their own licences.
Dr Harry Siviter, from the University of Texas at Austin, who led the study was quoted by the BBC saying, "Exposure to multiple pesticides is the norm, not the exception".
He added, "If you have a honeybee colony exposed to one pesticide that kills 10% of the bees and another pesticide that kills another 10%, you would expect, if those effects were additive, for 20% of the bees to be killed".
However, a "synergistic effect" could produce 30-40% mortality.
"And that's exactly what we found when we looked at the interactions" he said.
"So we really should consider the interaction between those chemicals" when licensing commercial formulas for use, Dr Siviter said.