Bumblebees sickened by an intestinal parasite are apt to visit flowers containing nectar and pollen that have a medicinal effect, a new study reports, indicating the current decline in the bee population could be abated through beneficial plants.
Iridoid glycosides, or secondary metabloites found in floral nectar, reduce common parasites in bees, previous research
has found. In this case, scientists from the University of Vermont, Dartmouth College, and the University of Colorado-Boulder increased concentrations of two iridoid glycosides – aucubin and catalpol – in turtlehead, a wetland plant frequented by bees in eastern North America. Some plants were given high volumes of iridoid glycosides, while the other half's iridoid glycosides were diluted with sugar water.
Parasitized bees -- afflicted with reproduction and foraging complications -- preferred the flower with the highest iridoid glycoside concentrations, the researchers found. Their results
are being published in the journal Ecology.
"We show that bees might be able to self-medicate, altering their foraging behavior when parasitized so as to maximize their consumption of beneficial plant secondary metabolite compounds," said senior author of the study, Rebecca Irwin, a faculty member at North Carolina State University who was formerly with Dartmouth, according