By Times Chronicle Staff
Simon Fraser University (SFU) researchers have found a new chemical compound that could help honeybees around the world fight off deadly mite infestations.
An estimated 45.5 per cent of Canada’s overwintering honeybee colonies died last winter, according to the Canadian Association of Professional Apiculturists (CAPA).
This represents the largest rate of colony loss in the country in the last 20 years, according to preliminary data gathered by the CAPA which surveyed commercial beekeepers across the country.
B.C. fared slightly better with about 32 per cent of honeybee colonies in the province perishing.
While a number of factors can lead to the deaths of bees including poor queens, weak colonies in the fall, weather and starvation, the main factor behind the losses is the varroa mite, a parasitic bug that attacks and feeds on bees.
The mites live off the larva and pupa of bees and grow into adult mites which also feed on the body fat of adult bees.
“In terms of the size of the problem, it is worldwide,” says SFU chemistry professor Erika Plettner. “In Canada, we register colony losses every year due to a variety of causes during wintering, but the weakness that the mites cause is definitely a factor.”
SFU researchers and members of the beekeeping industry led by Plettner are currently trialling the potential treatment at apiaries in British Columbia and Alberta.
“We discovered a substance that can paralyze the mites and eventually kill them, and it doesn’t seem to have too much of an effect on the bees,” according to Plettner.
“These field trials are very important to demonstrate efficacy in the colonies and are the next milestone toward actually using the treatment for real,” she says.
At one of the test sites in South Surrey, researchers are conducting a randomized trial using the chemical substance codenamed 3C36 involving 40 bee colonies that have been exposed to the varroa mite.
A deadly parasite of honeybees, varroa mites are a global problem for beekeepers.
Once they infiltrate a colony, the pests feed on bees, taking bites out of them, injuring them and making them vulnerable to secondary disease.
If allowed to fester, the mites can wipe out entire colonies over the winter months.
While a limited amount of chemical treatments currently exists, mites are starting to show signs of resistance, so it’s imperative to develop new treatments to increase the mix of options available to protect bee colonies in the long term.
“Like many discoveries, this was serendipity,” says Plettner. “We discovered this substance as part of a big screen we did for feeding deterrents for moth larvae. It was the best one we found, so when we started working with bees it was logical to test this substance on the mites.”
So far, Plettner says the results are encouraging.
Researchers put down sticky sheets with a grid underneath the test colonies and regularly sift through all the materials that fall to the bottom of a hive.
The grids are then documented and the number of dead mites found in hives being randomly treated with 3C36 compared to those treated with a control substance (one of the currently approved treatments) and those that are left untreated.
“The sticky sheets under the hives help us take a snapshot of what’s falling down and we can take them back to the lab, put them under a microscope and count them,” says Plettner.
“It’s very promising. We have noticed that our compound does cause greater mite fall than the control group.”
If the trial data continues to show successful results, Plettner says the next step will be to seek federal approval for the compound to be deemed safe for use and seek out commercial licensing partners.
“At this point, varroa management is a reality of beekeeping. In order to do this successfully and not lose our tools to resistance – which is just a part of evolution – we need to use different tools throughout the years,” says Plettner.
“Having very sick honeybees is not a good thing for other insects as well, since the viral diseases the mites vector can spread. This is why, as beekeepers, we have a responsibility to make sure our bees are healthy.”
