A dozen years ago beekeepers started reporting that frightening numbers of their honeybees (Apis mellifera) were mysteriously dying. Scientists have since discovered multiple reasons, but “diseases are by far the main cause of problems with honeybee health right now,” says Leonard Foster, professor of biochemistry and molecular biology at the University of British Columbia. The insects are afflicted by scourges ranging from varroosis (caused by mites) to the bacterial disease American foulbrood. Now a new study reveals how the smell of dead honeybees could be used to help identify and breed healthier colonies.
Scientists have long known honeybees remove dead or diseased individuals from among their young, or “brood,” to restrict the spread of pathogens through a colony. British Columbia researcher and study lead author Alison McAfee, along with Foster and other colleagues, wanted to better understand why some colonies are more fastidious about this cleanup than others are. They selected two chemicals naturally produced by honeybees, oleic acid and beta-ocimene, whose odors they thought might act as cleanup signals. Many insects release oleic acid at death, and honeybee larvae release beta-ocimene to signal their need for food. Young honeybees emit both compounds when they die.
