The lives of honeybees are shortened – with evidence of physiological stress – when they are exposed to the suggested application rates of two commercially available and widely used pesticides, according to new Oregon State University research.
In a study published in the journal PLOS ONE, honeybee researchers in OSU’s College of Agricultural Sciences found detrimental effects in bees exposed to Transform and Sivanto, which are both registered for use in the United States and were developed to be more compatible with bee health.
The western honeybee is the major pollinator of fruit, nut, vegetable and seed crops that depend on bee pollination for high quality and yield.
Coupled with other stressors such as varroa mites, viruses and poor nutrition, effects from these pesticides can render honeybees incapable of performing their tasks smoothly. Beekeepers and some environmental groups have raised concerns in recent years about these insecticides and potential negative effects on bees.
According to the researchers, this is the first study to investigate “sub-lethal” effects of sulfoxaflor, the active ingredient in Transform, and flupyradifurone, the active ingredient in Sivanto. Sub-lethal effects mean that the bees don’t die immediately, but experience physiological stress resulting in shortened lifespan.
In the case of Transform, the bees’ lives were severely shortened. A majority of the honeybees exposed to Transform died within six hours of being exposed, confirming the severe toxicity of the pesticide to bees when exposed directly to field application rates recommended on the label, the researchers said.
Study lead author Priyadarshini Chakrabarti Basu, a postdoctoral research associate in the Honey Bee Lab in OSU’s College of Agricultural Sciences, emphasized that the researchers aren’t calling for Sivanto or Transform to be taken off the market.
“We are suggesting that more information be put on the labels of these products, and that more studies need to be conducted to understand sublethal effects of chronic exposure,” Basu said.