Neonicotinoids (sometimes shortened to neonics) are a class of neuro-active insecticides chemically similar to nicotine. In the 1980s Shell and in the 1990s Bayer started work on their development. The neonicotinoid family includes imidacloprid, one of the most widely used insecticides in the world. Compared to organophosphate and carbamate insecticides, neonicotinoids cause less toxicity in birds and mammals than insects. Some breakdown products are also toxic to insects.
In the late 1990s neonicotinoids came under increasing scrutiny over their environmental impact. Neonicotinoid use was linked in a range of studies to adverse ecological effects, including honey-bee colony collapse disorder (CCD) and loss of birds due to a reduction in insect populations; however, the findings have been controversial. In 2013, the European Union and a few non EU countries restricted the use of certain neonicotinoids. [Wikipedia]