Honeybees in Kenya have Resilience to Diseases that Destroy Bees Elsewhere

Populations of East Africa honeybees appear to be resilient toward a number of devastating parasites and pathogens that affect bee colonies in Europe, the US and Asia, according to new research.

Among the pests that have ravaged honeybee colonies elsewhere in the world are Nosema microsporidia and Varroa mites.

Varroa mites, along with colony collapse disorder, are responsible for global honeybee populations crashing.

"Our East African honeybees appear to be resilient to these invasive pests, which suggests to us that the chemicals used to control pests in Europe, Asia and the United States currently are not necessary in East Africa," said researcher Elliud Muli of South Eastern Kenya University.

Varroa mites were first reported in Kenya in 2009, so honeybees there have proven resilient for a number of years.

"Kenyan beekeepers believe that bee populations have been experiencing declines in recent years, but our results suggest that the common causes for colony losses in the United States and Europe -- parasites, pathogens and pesticides -- do not seem to be affecting Kenyan bees, at least not yet," said Christina Grozinger, professor of entomology and director of the Center for Pollinator Research at Penn State University.

"Some of our preliminary data suggest that the loss of habitat and drought impacting flowering plants, from which the bees get all their food, may be the more important factor driving these declines," she said.

Penn State entomology research scientist Harland Patch suggested that there is a symbiotic relationship between bees and flowering plants.

"Honeybees are pollinators of untold numbers of plants in every ecosystem on the African continent," Patch said in a statement. "They pollinate many food crops as well as those important for economic development, and their products, like honey and wax, are vital to the livelihood of many families. People say the greatest animal in Africa is the lion or the elephant, but honeybees are more essential, and their decline would have profound impacts across the continent."

The researchers report that their study, which included a nationwide survey of 24 locations across Kenya to evaluate the numbers and sizes of honeybee colonies, assesses the presence or absence of Varroa and Nosema parasites and viruses, is the first comprehensive study of bee health in East Africa.

Varroa mites, the study reveled, are present throughout Kenya, except in the remote north. The Nosema virus was less widespread.

Pesticides were only found in low concentrations at all of the research sites.

Of the most common viruses that affect honeybees in the US, only three were found in Kenya bees.

"The Africanized bees - the so-called 'killer bees' - in the Americas seem to be having no problem with Varroa or diseases, so I would not be surprised to find they have some innate genetic tolerance to these pests," Patch said. "We suspect the seemingly greater tolerance of African bees to these pests over the western bees is a combination of genes and environment."

The researchers published their work in the journal PLOS One.