Research published recently has challenged the negative effect of one neonicotinoid insecticide on bees. The researchers from the University of Sussex found that exposure to clothianidin significantly affects the learning capacity of honeybees, but that it had no effect on bumblebees.

Clothianidin is one of three neonicotinoid insecticides subjected to heavy restrictions by the European Commission since 2013. These restrictions were put in place in light of concerns regarding potential health impacts on non-target species, especially honeybees.

The Sussex scientists specialise in the effects of pesticides on non-target creatures including bees. In the experiment, they exposed honeybee and bumblebee workers to the pesticide for 11 to 12 days and then assessed how bees learned to associate an odour with a sugar reward.

The scientists found that clothianidin impaired the ability of honeybees to learn this association, but the exposure had no adverse effects on bumblebees. The results could have implications for current and future insecticide regulations.