All pesticides have undergone extensive ecotoxicological testing and studies before they are registered and approved by the competent regulatory authorities. In particular in the European Union, there is a sophisticated testing and risk assessment system specifically for systemic pesticides such as neonicotinoids that prescribes which environmental safety data have to be generated and submitted before product registration can be granted.
In the case of most of our insecticide products, even by far more studies and more complex tests have been conducted than required by the respectively valid regulation. Among those, there are all kinds of different study types, from the basic laboratory test to the highly complex multi-site field study where all possible kinds of effects to bee colonies have been tested over several years.
For imidacloprid and clothianidin, Bayer´s neonicotinoids, for instance as many as more than 30 semi-field and field tests have been conducted by various testing facilities. Besides these studies, numerous special design tests have been conducted to investigate for instance chronic effects to adult bees, influences to the development of the brood, effects to the behavior of bees and other sublethal effects. In their entirety, these studies cover all potentially relevant testing endpoints such as mortality, foraging activity, reproduction, development of larvae and pupae, nectar and pollen storage behavior, colony health and strength, bee individual behavior, and many more.
In the studies that have been conducted it has been found that under realistic field conditions bee colonies are not affected in any of the assessed parameters by applications of imidacloprid or clothianidin when they are conducted according to the respective safe use instructions. Likewise it has been shown that bee colonies that are foraging on neonicotinoid seed-treated crops under natural conditions are not damaged, not even after long-term exposure.
These tests were critically evaluated by the competent regulatory authorities, before authorization was granted for the respective products.