Not only has research shown that insecticides are detrimental to honeybees, but this new study has found that they have lower quality food sources in intensively managed agricultural land. Since the end of the Second World War crop yield on arable land had increased dramatically. This increase in productivity has been achieved by hedgerow removal, larger field sizes and less variety in crop species. These changes to farming practices have decreased the complexity of the landscape and therefore decreased biodiversity. It is therefore no wonder that honeybees have less plant species to feed on.