Research Brief: The varroa destructor

Our research on bee health remains crucial for both humans and nature. The University of Guelph is a global leader on this research and is working with 300 hives at 13 locations to better understand bee health. On campus, part of the process to advance research is to train new students on how to be researchers and navigate the apiary.

Dr. Ernesto Guzman is a University of Guelph professor and the director of the Honey Bee Research Centre/ Pinchin Fam. For over 15 years Dr. Guzman has been teaching and researching at the University of Guelph. Before accepting a position at the University of Guelph, Dr. Guzman completed his Ph.D and M.S. in entomology at the University of California, Davis. Dr. Guzman’s passion for honey bees began when he was 17 year-old and began keeping his own bees.  Dr. Guzman is author or co-author of more than 120 peer-reviewed publications and is recognized as a world authority in honey bee breeding and parasitic diseases of bees.

What follows below is note directly from Dr. Guzman about the state of research at HBRC.

The current research conducted at the Honey Bee Research Centre (HBRC) is a response to the high mortality rates of honey bee colonies. More than one third of the honey bee colonies in Ontario and Canada died, on average, during the past 13 winters. This level of colony mortality has no precedent and beekeepers do not fully understand what is happening to their colonies and how to reduce their losses. These colony die offs are worrisome because the annual incremental value of bees as pollinators of crops in Ontario exceeds 100 million dollars and that value for all of Canada exceeds one billion dollars.

Results of studies conducted by our team suggest that bees are dying as a consequence of combined effects of several stressing factors. The factors more frequently associated to die offs and poor population growth of honey bee colonies are parasites and pathogens; the blood-sucking mite Varroa destructor, the deformed wing virus transmitted by the varroa mite, and the fungus Nosema ceranae, which causes intestinal infections in the afflicted bees. Additional stressors to the bees include pesticides of two kinds, those used by beekeepers to treat their colonies against the varroa mite and pesticides used by farmers to control crop pests and diseases. Therefore, we have focused on these factors to understand how they affect honey bee health and above all, how to minimize their impact on bees. It is important to keep our bees healthy and alive, and that is our main concern at the HBRC.

Below is the article citation that corresponds with the deep dive investigation wherin Dr. Guzman and fellow researchers share of the how the Varroa destructor mite is the main culprit for the death and reduced populations of overwintered honey bee colonies in Ontario, Canada.

Guzmán-Novoa, E., Eccles, L., Calvete, Y., Mcgowan, J., Kelly, P., & Correa-Benítez, A. (2010). Varroa destructor is the main culprit for the death and reduced populations of overwintered honey bee (Apis mellifera) colonies in Ontario, Canada. Apidologie, 41(4), 443–450.

For more information about Dr. Guzman and for a selection of featured articles please visit his U of G profile here.