For years now, much of the focus on global bee populations has been on agriculture’s use of neonicotinoids, a widely used class of insecticides. So much concern has been raised about neonicotinoids that, in 2013, the European Union put very tight limits on three such insecticides — clothianidin, imidacloprid, and thiamethoxam — on crops that attract pollinating bees (France has since banned their use outright.) But new research out of Sweden shows that not all neonicotinoid insecticides have negative effects on bees — even more eyebrow-raising is that certain neonicotinoids could actually benefit bumblebees and pollination.
In a field study, the researchers Maj Rundlöf of Lund University and Ola Lundin of the Swedish University of Agricultural Sciences have found that the neonicotinoid thiacloprid does not have any detectable negative impact on bumblebees. When the insecticide was used on red clover fields, insect pests were successfully controlled while at the same time more bumblebees came to visit and pollinated the crop.
Not insignificant is that this further shows that broad celebration or broad criticism of agricultural technologies, chemicals, and production methods are not wise. Rather, a more nuanced, case-by-case approach is prudent. This new research is published in the journal ACS Environmental Science and Technology.
According to the authors, the data indicate that neonicotinoid thiacloprid (one that is still permitted in the EU) could actually benefit bumblebees rather than harming them. The risk of direct impact on the bumblebees is low, while the thiacloprid protects the flowering fields where the bumblebees feed.
“Our study shows that neonicotinoids should not be treated as a homogenous group when evaluating the environmental risks of insecticides. There are pest management solutions that do not detectably harm bumblebees,” Rundlöf said.
If the recently studied neonicotinoid thiacloprid meets the same fate as the three neonicotinoids that have had limits placed on them in Europe, it could lead to negative consequences for bumblebees, according to Rundlöf.
“If this effective pest management solution was to disappear from the market without there being an adequate alternative, farmers would most likely grow less red clover seed and this would mean less food for the bumblebees,” she said.
Thiacloprid is on the EU list of candidates for substitution, meaning it could be banned in the near future. This is because it has been found to have endocrine disruptive properties. However, Rundlöf hopes future studies can build on the findings from this research.