In 1994, French beekeepers started to blow the whistle on the abnormal behaviour and disappearance of their bee colonies foraging on sunflowers and maize. Quickly, beekeepers considered “Gaucho”, a new neonicotinoid authorised the same year for the treatment of sunflower and maize seeds, as the prime suspect.
Were these two events linked by a causal relation or purely coincidental? Neonicotinoids are chemicals which attack the nervous system of all insects, and thus can have a lethal impact on bees. They were nonetheless authorised, under the condition that they are not to be used over a dose previously identified by the industry, and accepted by the regulator, as being non-lethal for bees. However, french beekeepers observations questioned the scientific grounds of this decision. Was the non-lethal dose correctly identified? Furthermore, do neonicotinoid insecticides have chronic sub-lethal effects on bees which were not foreseen when they were authorised?