Bees' sat nav broken by pesticides
Neonicotinoid pesticides are used around the world to protect major crops like oilseed rape (canola).
In field tests, Dave Goulson of the University of Stirling, UK, found that food treated with realistic levels of imidacloprid, a neonicotinoid, dramatically slowed the spring growth of colonies of buff-tailed bumblebees.
Dosed colonies also produced 85 per cent fewer queens than clean ones. A second study offers further insight. Mickaël Henry of France's National Institute for Agricultural Research in Avignon fed low levels of a neonicotinoid, thiamethoxam, to European honey bees.
Dosed beeswere less likely to return to their hives after foraging, suggesting the pesticide impaired their ability to navigate. The findings will add weight to calls for neonicotinoids to be banned, or more strictly regulated.