Thiacloprid neonicotinoids benefit bumblebees and pollination

Neonicotinoid pesticides, chemically similar to nicotine in the tobacco plant, which many insects do not like, are seed treatments created to protect plants when they are most vulnerable to pests. They were also designed to be better for the environment, including non-pest insects, but a statistical blip in bee numbers set off claims that the new pesticides were to blame, and scientist findings that the problem was changing land use patterns and varroa mites fell on deaf ears.

A new study affirms that scientists were right all along; at least some neonicotinoid pesticides even improve outcomes for bees and pollination.

Though the European Union tends to make environmental and food policy on popular opinion rather than science, the new work may introduce some sound thinking to politics. It 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.

The study also showed that the bumblebee colonies close to the thiacloprid-treated red clover fields grew larger in comparison with bumblebee colonies in landscapes without red clover fields.

The research therefore indicates that certain neonicotinoids that are still permitted in the EU could actually benefit the 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. However, thiacloprid is on the EU list of candidates to be banned because environmentalists claim it has endocrine disruptive properties.