A class of pesticides that has been linked to declining bee populations harms the reproductive capacity of male honeybees, not just that of queens as other research has shown.

Neonicotinoid pesticides are currently banned by the European Union because of their effects on bees. Lars Straub at the University of Berne and his team exposed colonies of honeybees (Apis mellifera) in the field to two neonicotinoids that are commonly found in agricultural fields. The team found that in males, the chemicals reduced living sperm count by 39% and decreased the insects' lifespan.

This could negatively affect honeybee colony fitness and queen survival and health, the authors say.

Proc. R. Soc. B 283, 20160506 (2016)