So-Called ‘Safe’ Pesticides Could Still Hurt Some Honey Bees

According to a team of researchers from the University of California in San Diego, a pesticide that has been deemed safe for honey bees may actually endanger certain demographics of these bees, especially if it is used alongside other chemicals, such as fungicides. Sivanto, which was developed by the company Bayer CropScience AG, has been stated to have been designed for killing agricultural pests but not crucial pollinating species like honey bees.

Farmers have been allowed to make use of Sivanto for blooming crops due to this so-called design, but the pesticide may still cause harm to honey bees called foragers, because Sivanto was tested on just honey bees inside of hives, as per the UC San Diego researching team. Representatives from Bayer CropScience have yet to comment on these new discoveries.

The UC San Diego researchers said that in-hive honey bees are typically younger while foraging bees are often older. Though Sivanto was customized to not endanger in-hive, younger honey bees, the foragers outside the hive would still have to bear the full force of the pesticide’s effects, per the research team, who just published their findings in a scientific journal called Proceedings of the Royal Society B. “Our results highlight the importance of assessing the effects pesticides have on the behavior of animals, and demonstrate that synergism, seasonality, and bee age are key factors that subtly change pesticide toxicity,” says Simone Tosi, a UC San Diego postdoctoral fellow and one of two co-leading authors for the study.

The team discovered that forager honey bees that were exposed to crops hit with Sivanto, as well as at least one standard fungicide, were about four times as likely to either die or demonstrate atypical behaviors, including apathy and poor coordination, when compared with in-hive, younger honey bees. Also, the exposed honey bees, per Tosi, suffered more of these harmful effects in summer and not during spring.

Currently, Sivanto is available for purchase in 30 countries throughout North America, South America, Europe, Asia, and Africa, and 65 more countries are planning to approve the pesticide in the future, as per the UC San Diego research team. “The idea that this pesticide is a silver bullet in the sense that it will kill all the bad things but preserve the good things is very alluring but deserves caution,” says James Nieh, who is a professor and the other lead co-author for this study.