Fruit & Vegetable Magazine

Features Chemicals Insects
Keeping bees


October 3, 2013
By David Manly


Topics

Oct. 3, 2013 – A common sight in the spring and summer, bees are one of the most important workers within Canadian ecosystem and agriculture industry – especially honeybees.

Not only do these bees in Canada create honey (an over $100 million industry), but they also help pollinate a wide variety of crops, which helps contribute an estimated $1.3 to $1.7 billion annually. If you add in the contributions of other Canadian bee species, such as alfalfa leafcutting bees and bumblebees, the value leaps up to an estimated $2.8 billion.

And without bees, many crops including fruits and vegetables would not be able to produce nearly as well – so, why are so many people concerned with bees dying?

Advertisement

Dr. Richard Fell, a professor of entomology at Virginia Tech says that that is the real question – no one really knows. “Each year, bee keepers lose about 30 per cent of the hives that they manage,” he says.

“What this means is that it makes it more difficult for growers, who produce crops such as almonds which require honey bee pollination, to obtain the hives necessary for pollination … As colony numbers decline it becomes harder to get bee colonies for pollination purposes, placing growers in a difficult position”

Phases of blame

Fell says that instead of one or two potential factors that could be the cause of the bee deaths, known as Colony Collapse Disorder (CCD), there are probably multiple factors which could interact and cause unexpected deaths. The possibilities range from parasites (particularly the Varroa mite), queen quality, nutrition, changes in the environment, pesticides and pathogens.

“So, it is not something that we can simply say, if a hive has A, B or C, that the colony is going to die. We just don’t know,” he adds. “To date, we have no smoking gun – no one factor that we can look at as the primary cause”

According to Fell, the media and public often shift the blame to a particular cause of CCD based on the latest data or research paper, because a solution is so badly needed.

Currently, the trend is centred on the varroa mite and neonicitinoid pesticides, an insecticide that is similar to nicotine. However, Fell simply says that the data aren’t there to implicate either of them as the main cause. “And if we look in terms of the levels [of neonicitinoids in bees], we are talking of levels on the order of one to two parts per billion.”

“And when you have very, very low exposure levels, people often forget that bees can detoxify these compounds. And if you feed bees levels like that, it appears to have little or no effect on colony survival or colony activity.”

The business perspective

Derrick Rozdeba, a communications and marketing specialist with Bayer CropScience, says that actual bee numbers are not declining, but have been increasing. “Over the last eight years, when beekeepers have opened their hives in the spring, there have been fewer bees that have survived,” he said.

“And at some point, beekeeping can become unsustainable, as the need to replace lost bees increases. What has been declining in Canada aren’t bees, but rather beekeeper numbers.”

He also says that the best way growers can assist the honey bee is to effectively communicate with one another and implement suitable management practices for seed treatments, insecticide use and more to help increase awareness and reduce risk. “Growers need to be aware that there can be things that they do in their normal operations which may have negative effects on honey bees and other pollinators.  The production of dust during seeding operations can be a conduit of pesticide exposure to bees, as can the application of post emergence insecticides when crops are in flower.”