A new study has revealed how the bees defend themselves from different types of infections. The interaction between plants, pollinators and parasites has been studied by the researchers from the University of Massachusetts and Dartmouth College and they discovered that the bumble bees which consumed natural toxins present in plant nectar, including nicotine and caffeine, were less likely to get infected with Crithidia bombi, a common intestinal parasite. The researchers said “We found that eating some of these compounds reduced pathogen load in the bumble bee’s gut, which not only may help the individual bees, but likely reduced the pathogen Crithidia spore load in their feces, which in turn should lead to a lower likelihood of transmitting the disease to other bees.”
According to the researchers, toxification of nectar helps the plants to protect themselves against spoilage by yeast and other microbes. These compounds provide a chemical defense system to the plants. The researchers added “Maybe the compounds are deterrent to nectar robbers, who take nectar without pollinating and yes, nectar robbing is indeed a thing.” The study also unveiled that these secondary metabolites like terpenoids, glycosides and alkaloids, strongly reduce parasite load.
Although the infected bees are not much benefited by these secondary metabolites, they play an important role in reducing the intensity of infections and thereby reducing the transmission within and between the colonies. The researchers concluded “With so many people looking at bee health these days, it’s taken a long time for us to realize that perhaps we should be paying attention to how floral secondary compounds mediate pollinator dynamics and their interactions with pathogens.”