When Varroa was first discovered on Kenyan bees in 2010, a team of scientists from the USA and Africa set out to study the effects of the mite on East African bee populations. The team found that despite the untreated Varroa infestation, African bees are surviving. They did not seem to be actively fighting or removing the mites, instead they had a higher tolerance for living with them.
The scientists are now trying to discover the mechanisms that allow honey bees to be more resistant. “If we can understand the genetic and physiological mechanisms that allow African bees to withstand parasites and viruses, we can use this information for breeding programs or management practices in US bee populations,” said Christina Grozinger, Director of the Center for Pollinator Research at Pennsylvania State University and one of the co-authors of the study.
The scientists are now sequencing genomes of individual bees from different parts of Kenya to identify specific genes that have helped the bees to adapt to different environments and potentially develop the ability to resist different diseases.
Helping bees to help themselves
Studying the African bees, the researchers also discovered a link between elevation and Varroa: bee colonies at higher elevations had higher instances of Varroa. This suggests that a bee’s environment may make it more or less susceptible to the mites. And since environment is also closely related to nutrition – higher elevations often have less flowering plants which mean less food options for honey bees, so improving bee nutrition could be a way to combat Varroa, say the scientists. Their conclusion: Increasing the diversity of plant species could potentially help bees to help themselves by increasing a bee’s natural ability to tolerate Varroa.
The original study, titled “Evaluation of the Distribution and Impacts of Parasites, Pathogens, and Pesticides on Honey Bee (Apis mellifera) Populations in East Africa” by Elliud Muli et.al. was published in 2014 in the scientific online journal PLoS One. The study was funded by the U.S. National Science Foundation (NSF).
The follow-up article, titled “Honey Bees’ African Ancestors May Hold Cure for Biting Mite Plague” has recently been published on “Live Science”, an online platform that features developments in science, space, technology, health, the environment, culture and history. The author is Jessica Arriens, a public affairs specialist for the U.S. National Science Foundation.