Research suggests that some of the world's most commonly used pesticides are killing bees by damaging their ability to navigate and reducing numbers of queens. Many causes have been suggested, including diseases, parasites, reduction in the range of flowers growing wild in the countryside, pesticides, or a combination of them all. The French research group investigated the impact of a different neonicotinoid, thiamethoxam, on the number of bees able to make it back to the colony after release.
Scientific groups in the UK and France studied the effects of neonicotinoids, which are used in more than 100 nations on farm crops and in gardens. Often the chemical is applied to seeds before planting. As the plant grows, the pesticide is contained in every part of it, deterring insect pests such as aphids. According to Dr Goulson, the use of these pesticides is so extensive that most bee colonies in areas of arable farming are likely to be exposed to them, so there is possible for them to be playing a significant role in suppression of bee populations on a pretty staggering scale.