According to newly published research from Israel, humans aren’t the only ones addicted to nicotine and caffeine – so, possibly, are bees.
A study conducted at the University of Haifa shows that bees prefer nectar with small amounts of nicotine and caffeine over nectar that does not contain these substances at all.
Flower nectar is primarily comprised of sugars, which provide energy for the potential pollinators. But the floral nectar of some plant species also includes small quantities of substances known to be toxic, such as caffeine and nicotine. Not surprisingly, nicotine is found primarily in the floral nectar of various types of tobacco tree, while caffeine is found mostly in citrus flowers, particularly grapefruit which has a relatively high concentration.
In an attempt to determine whether the bees prefer this nectar the researchers, led by Izhaki, Prof. Gidi Ne’eman, Prof. Moshe Inbar and Dr. Natarajan Singaravelan from the university’s Department of Environmental and Evolutionary Biology and the Department of Science Education, offered the bees artificial nectar composed of various levels of natural sugars and various levels of caffeine and nicotine, alongside “clean” nectar that comprised sugar alone.
Bees choose caffeine and nicotine
The results showed that bees clearly prefer nectar containing nicotine and caffeine over the nectar containing just sugar. Their favorite nicotine concentration was 1milligram per liter, similar to that found in nature. However, given a choice of higher levels of nicotine or clean nectar, the bees preferred the latter.
The researchers said they could not determine for certain whether or not the presence of the addictive substances in the nectar evolved to make pollination more efficient.
They did suggest, however, that the study shows that the plants that survived natural selection are those that developed the levels of these addictive substances that attract and do not repel bees, thereby giving them a significant advantage over other plants.
The researchers also say that while the bees clearly prefer the nectar containing caffeine and nicotine, they will be conducting further studies to discover whether they also become addicted to the toxic substances.