Professor investigates chemical compounds to control honey bee parasites

The chemical compounds would help preserve honey bee colonies

The photo is of a bee hive where multiple honey bees are entering and exiting a beekeeper box.
Varroa mites can infect and collapse entire colonies. PHOTO: Damien Tupinier / Unsplash

By: Charlene Aviles, Peak Associate

Bees play a crucial role in agriculture, especially in pollinating crops. SFU chemistry professor Dr. Erika Plettner has been researching chemical compounds to control varroa mites, which are parasites that threaten honey bee colonies. 

The Peak interviewed Plettner to learn more about her research.

“The varroa mite only attacks honey bees [ . . . ] but some of the viral diseases and other pathogens that honey bees might carry, can spread,” said Plettner.

Plettner added, “The injuries that the mites do to the bees don’t heal, and they can be the entry point for secondary infections and diseases. And this can really lead to a sudden collapse of the colony and a loss of the colony.”

Plettner explained without enough pollinators to pollinate crops, farmers import beehives and bees. Imported beehives are a temporary solution to offset the lack of pollinators. However, it is a costly and time-consuming option for beekeepers, which leaves many crops unpollinated in the meantime.

To address the varroa mite problem, Plettner and her team have been testing chemical compounds to control the mite population. They compared the chemical compounds’ effectiveness to a control group. She added this is a timely concern, considering beekeepers usually treat their hives for mites in the fall.

“What you really want in this case is that you want the compound to really work well on the mites but without having really acute effects on the bees. This is what the therapeutic ratio is, and this is true for any medicine,” said Plettner. She explained the therapeutic ratio as having a high effect on the area you’re trying to treat but a low effect on the host of the disease. In this case — a strong effect on varroa mites while leaving honey bees unaffected. 

Plettner hopes the research would provide beekeepers with more options for treatments against varroa mites. She highlighted the importance of rotating between different treatments to prevent the varroa mites from developing immunity.

Plettner explained using the same compound would cause the mites to develop a resistance — causing the therapeutic ratio to become smaller. “At some deep level every compound will have what is known as a sort of ‘background effect’ or ‘non-lethal effect’ that could in the long term be a problem,” said Plettner.

The team is currently in a trial phase of the study and is continuing to “assess the efficacy of this treatment.”