Researchers at Newcastle University and Trinity College Dublin have discovered that at least some bee species have a preference for nectar containing pesticides. Specifically, they prefer nectar containing neonicotinoid pesticides. Bees cannot taste neonicotinoids that end up in their food and so do not avoid these pesticides like they do with some others. Unfortunately, the neonicotinoids have an effect on bee brain chemistry similar to nicotine’s affects on human brain chemistry.
Scientists found that bees preferred nectar laced with neonicotinoids, leading them to argue that the bees are, in effect, addicted to the chemicals. As with nicotine in humans, though, these chemicals have negative effects on the fitness of individual bees and on entire colonies.
Neonicotinoids have been questioned as a culprit in mass bee die-offs in recent years, and in April 2013, the EU issued a temporary ban on the use of pesticides containing neonicotinoids, pending further research. They are still in wide use in the United States, though, and if more detailed research doesn’t come out in the near future, they might end up being used in Europe again as well.
These pesticides can decrease foraging range, which can result in insufficient food for colonies, beginning a downward spiral toward colony collapse. They can also end up on plants that were not intentionally treated with such pesticides, making them an even larger part of bee diets. As bees continue to eat nectar containing these chemicals, they will continue to suffer its effects to greater degrees.
Bees and other pollinating insects are essential to the healthy reproduction of many plant species, and mass die-offs of bees can have huge ecological impact. The agricultural industry alone values such insects at around €153 billion a year globally. Beyond money, though, wildflowers and trees that cannot reproduce without the help of insects could be negatively affected, upsetting local ecosystems at a grand scale.