Review of Bee Health

A University of Saskatchewan research collaboration with the Saskatraz Honeybee Breeding Project has identified how the Varroa destructor parasite suppresses the immune system in honeybees, a species that helps produce about one third of the world’s food crops through pollination. They have also developed a tool to help breeders select bees resistant to the parasite and associated disease-causing microorganisms.

“Our study offers insights into why Varroa-susceptible bees run into trouble,” said Scott Napper, one of the lead authors of a study published May 21 in the journal Frontiers in Genetics. Napper is a professor of biochemistry at the U of S and senior scientist at the Vaccine and Infectious Disease Organization-International Vaccine Centre (VIDO-InterVac).

“Once they are Varroa infested they become more immune compromised,” he said. “This leads to a number of secondary infections that likely leads to the death of the bees and the collapse of the colony.”

Saskatraz was founded in 2004 by honeybee breeder and molecular biologist Albert Robertson, working in cooperation with Saskatchewan beekeepers. By putting bee colonies under pressure of Varroa infestation without treatments to protect them from the mites, then breeding the survivors, the project has had success in identifying Varroa-resistant bees.

“Our breeding and research work is recognized globally,” said Robertson, who is also CEO and senior scientist with Meadow Ridge Enterprises near Saskatoon. “To my knowledge, we are the first to combine naturally selected stock, that is, survivors, with defined behavioral traits for Varroa resistance. Selection of these phenotypes allowed us to use established molecular techniques to identify potential molecular markers.”