Scientists reveal a tiny suspect in honey bee decline

Honey bee colonies have been undergoing mysterious declines worldwide for the past decade, with scientists speculating that pesticides, pathogens, mites and certain beekeeping practices have all contributed to the decline. Now, biologists have discovered that a tiny single-celled parasite may have a greater-than-expected impact on honey bees.

Scientists from University of California, San Diego have reported in the journal PLOS ONE that a microsporidian called Nosema ceranae, which has been known to infect adult Asiatic and European honey bees, can also infect honeybee larvae. They also discovered that honey bee larvae infected with the microsporidian have reduced life spans as adults.

Nosema ceranae, a kind of fungal pathogen spread by spores, has been implicated in colony collapse because it reduces colony health and is widespread. However, previous research has suggested that the microsporidian could not infect honey bee larvae.

“We hope that our study will spur further research into how Nosema ceranae is transmitted and into the potential infection of larvae in natural and managed honey bee colonies in the field,” said James Nieh, a professor of biology at UC, San Diego.