Vanishing bees threaten food supply

U.S. authorities estimate that about 31 per cent of all U.S. honey bee hives ceased functioning during the year 2012

What do cherries, kiwi fruit, cashews, watermelon, cucumbers, squash, apples, avocados and raspberries have in common, besides being edible? They all require bees for pollination to produce the food that we eat from these plants. Of course, these aren’t the only food plants that require pollination — the list is extensive, with the UN estimating that 70 of the world’s 100 most important food plants are dependent on cross-pollination by bees. Further, it is estimated that up to 90 per cent of wild plants require bees for pollination.

For centuries farmers in Europe and North America never worried about their crops being pollinated — every spring the bees showed up on schedule, and for those areas where bees weren’t naturally plentiful, there were beekeepers who rented out their hives.

However, that all began to change about 15 years ago in Europe and North America and more recently at numerous other localities around the world. Bees began disappearing — not just a few, but whole hives at one time. U.S. authorities estimate that about 31 per cent of all U.S. honey bee hives ceased functioning during the year 2012. This mass disappearance has been labelled Colony Collapse Disorder, but of course giving some phenomena a name doesn’t explain its cause or solve the problem.

So what is going on with our bees? Why are seemingly healthy bees abandoning their hives? As with many things in nature, finding an answer is not always simple and often there are multiple factors working together to cause the problem.

Climate warming, habitat loss and mites have all been suggested as possible causes, and while there is some evidence that they are contributing to the problem, more recent studies indicate that the major factor is the use of a certain class of pesticides called neonicotinoids.

These chemicals are used to coat the seeds of many crops including corn, wheat and soy and are found in many home gardening products. Recently published research has shown that the chemicals are absorbed by the plants that grow from the seeds and contaminate the pollen and nectar that the bees are gathering in their rounds. In the bees, the chemicals act as a nerve agent and disrupt their homing ability so they have trouble finding their way back to the hive.

Recently the European Union banned the use of neonicotinoids on crops that would be used by bees, and many scientists are arguing for the same ban in Canada and the U.S. The manufacturer of these chemicals, German-based Bayer, argues that there is not yet enough evidence to blame their chemicals.

However, with bees being essential for the production of at least 30-40 per cent of our food supply it would seem prudent to err on the side of caution. A massive die-off of these critical pollinators would be a catastrophe for our food supply and severely impact many of the world’s ecosystems. There is no known effective way to artificially pollinate all the food plants that depend on bees.

It seems to me that if we ban these insecticides for a few years the downside is limited — lack of these pesticides might cut food production by a small amount; the upside is huge — we reverse the loss of bee populations and save the world’s food supply. Sometimes we have to act before the data is absolutely conclusive, and in the case of our food supply it would seem that erring on the side of caution would be the prudent thing to do.

The regular monthly meetings of the South Okanagan Naturalists’ Club are not held during June, July or August. However, we do continue with our Thursday birding trips and have additional outings two or three times a month to other locations. Check out our website www.southokanagannature.com to keep up with what’s happening.

 

 

 

Bob Handfield is president of the South Okanagan Naturalists’ Club but the views expressed here are his own and not necessarily those of the club.