SFU researchers test new honey bee protection

By Times Chronicle staff

Simon Fraser University (SFU) researchers have discovered a new chemical compound that could help honey bees around the world fight off a deadly mite infestation.

According to the Canadian Association of Professional Beekeepers (CAPA), about 45.5 percent of overwintering honey bee colonies in Canada died last winter.

This represents the largest rate of colony loss in the country in 20 years, according to preliminary data collected by CAPA, which surveyed commercial beekeepers nationwide.

BC fared slightly better, with about 32 percent of the province’s honey bee colonies destroyed.

While a number of factors can contribute to bee deaths, including weak queens, weak colonies in the fall, weather and starvation, the main factor behind the losses is the varroa mite, a parasitic insect that attacks and feeds on bees.

Mites live off the larvae and pupae of bees and develop into adult mites that feed on the body fat of adult bees.

“In terms of the scale of the problem, it’s worldwide,” says SFU chemistry professor Erika Plettner. “Colony losses are recorded every year during wintering in Canada for a variety of reasons, but tick-induced vulnerability is definitely a factor.”

SFU researchers and members of the beekeeping industry, led by Plettner, are currently testing the potential treatment at apiaries in British Columbia and Alberta.

“We’ve discovered a substance that can paralyze ticks and eventually kill them, and it doesn’t have much of an effect on bees,” he said. Plettner.

“These field trials are critical to demonstrating efficacy in colonies and are the next step in actually using the treatment,” he said.

At one trial site in South Surrey, researchers are conducting a randomized trial using the chemical code-named 3C36 involving 40 bee colonies exposed to the varroa mite.

Varroa mites, a deadly parasite of honey bees, are a global problem for beekeepers.

After penetrating a colony, the pests feed on the bees, stinging them, injuring them and making them susceptible to secondary disease.

If allowed to fester, ticks can wipe out entire colonies during the winter months.

Although a limited number of chemical treatments are currently available, mites are beginning to show signs of resistance, so it is important to develop new treatments to increase the mix of options available to protect bee colonies in the long term.

“Like many discoveries, it was a fluke,” says Plettner. “We discovered this substance as part of a large screen we did for feeding moth larvae. It was the best we could find, so when we started working with bees, it made sense to test this substance on mites.”

So far, Plettner says the results are encouraging.

The researchers put sticky layers of netting under the test colonies and regularly sift out any material that falls to the bottom of the hive.

The nets are then documented and the number of dead mites found in hives randomly treated with 3C36 compared to those treated with the control substance (one of the currently approved treatments) and left untreated.

“The sticky sheets on the bottom of the hives help us take pictures of what’s falling, and we can take them back to the lab and put them under a microscope and count them,” says Plettner.

“This is very encouraging. We found that our compound caused more ticks to 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 and commercial licensing partners for the compound to be deemed safe for use.

“At this point, varroa control is the reality of beekeeping. To do this successfully and not lose our tools for resistance, which is just part of evolution, we have to use different tools over the years,” says Plettner.

“Having a lot of sick honeybees is not good for other insects either, because the tick vector can spread viral diseases. Therefore, as beekeepers, it is our duty to ensure that our bees are healthy.”

Endangered bees are the subject of a Desert Society film and lecture Saturday

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