Cure for Honeybee Colony Collapse Disorder?
It seems that the culprit may have been a specific pathogen: Nosema ceranae (Microsporidia). Researchers in Spain apparently identified the pathogen in professional apiaries and treated it with antibiotics in affected colonies, showing a complete rebound after successful treatment.
In a study published in the new journal from the Society for Applied Microbiology: Environmental Microbiology Reports, scientists from Spain analysed two apiaries and found evidence of honey bee colony depopulation syndrome (also known as colony collapse disorder in the USA). They found no evidence of any other cause of the disease (such as the Varroa destructor, IAPV or pesticides), other than infection with Nosema ceranae. The researchers then treated the infected surviving under-populated colonies with the antibiotic drug, flumagillin and demonstrated complete recovery of all infected colonies.
Is this the final solution for eradicating CCD and restoring bee colonies to their previously healthy states? Or is this treatment merely a single symptom obscuring an underlying undiagnosed problem? Hopefully this research and treatment stands up when applied to other instances of CCD from other regions.
UPDATE (4-15-09): A paper on the subject of Nosema ceranae infection in honeybees, and how it can lead to CCD, can be found here (Mariano Higes, et al). Apparently Nosema ceranae has been identified in French and other European honey bee hives, as well as in Costa Rican killer bee colonies. It may be that Nosema ceranae hitches a ride into the bee colonies on foraged pollen. Also, it seems that Nosema ceranae was first described as an infectious agent at least as far back as 1995 by visiting a researcher studying bees in China. But little more was reported on the subject or much further inquiry made.
In 1995, Professor Ingemar Fries of the Swedish Agricultural University, Uppsala and an expert on Nosema in bees, visited China where he described a new microsporidium, Nosema ceranae, in indigenous honey bees Apis cerana (Fries et al. 1996). The differences between the two microsporidia, Nosema apis and Nosema ceranae, lie in their ultrastructure and genetics (see Fries et al 2006). Though Professor Fries subsequently demonstrated in experiments that Nosema ceranae is infective for the western honey bee, little more was made of the observations until the spring of 2005, when I was contacted by Dr Dinh Quyet Tam of the Bee Research and Development Centre (BRDC) in Hanoi, Vietnam, whose honey bees (Apis cerana and Apis mellifera) were suffering from Nosema disease. Julia Klee and Andrea Besana, working with me at Queen’s University, Belfast, then developed a rapid and accurate molecular genetic detection system to differentiate Nosema apis from Nosema ceranae and found the Vietnamese honey bees to be infected exclusively with Nosema ceranae. In summer 2005, a group of Taiwanese researchers also found Nosema ceranae in Taiwanese Apis mellifera (Huang et al. 2006). It might have been anticipated that the western honey bee would acquire Nosema ceranae if kept in Asia, where Apis cerana and its parasite Nosema ceranae are endemic.
A group of bee pathologists in Spain, led by Dr Mariano Higes, subsequently discovered Nosema ceranae to be widespread in Spanish honey bees Apis mellifera, as of 2005 (Higes et al. 2006), indicating that the parasite had moved out of Asia. Dr Higes’ group have subsequently reported the disease in France, Germany and Switzerland (2nd EurBee Conference, Prague, September 2006). More worryingly still has been the massive colony losses in Spain over the winter of 2005-2006, some of which have been linked to Nosema disease.
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Toronto, Ontario, Canada