Best of Pure Green | Bee Decline
Is There Reason To Be Concerned?
This Ecological article originally appeared in Pure Green Magazine, Issue 5 and was written by regular PGM contributor Charles Nock; illustrated by Bess Callard.
Busy like a bee. Indeed, we humans generally respect the solid work ethic of one of our closest insect allies, but truth be told, the bees are getting a raw deal. For example, did you know that the value of honeybee pollination in Canada is estimated to be more than one billion dollars a year? Um-hum, the check is in the mail I hear.
The relationship between honeybees and humans is reported to stretch back to the time of the Egyptians. More recently, the European honeybee (Apis mellifera) was brought to Canada from Europe in the 1600s by early settlers. Since then, honeybees have become widespread in North America (“wild” honeybee colonies in North America derive from domesticated hives). In Canada, the first recorded use of honeybees was around the 1820s in Quebec, and then use spread to Ontario around the 1830s.
Incredibly important to our food production system—in environmental speak they provide an ecosystem service—honeybees pollinate more than ninety different farm-raised plants. Our dependence on their diligent pollination service is the reason that concern over honeybee colony mortality erupted amongst beekeepers in North America in 2006. While it is normal for honeybee populations to experience mortality from causes such as mites, disease, and stress, keepers in North America witnessed a jump in colony mortality from 17-20% to 30-70%, which came to be know as colony collapse disorder (CCD).
SYMPTOMS OF COLONY COLLAPSE DISORDER
What differentiates CCD from the losses of colonies experienced by beekeepers previously? Beekeepers have pointed to a number of peculiar characteristics of “collapsed” hives: the sudden disappearance of almost all of the worker bees, the absence of dead bees at the hive, a queen and a small number of very young bees are the only remaining bees in the hive, and food stores (pollen and honey) that are still abundant.
CAUSES OF CCD
Fast forward to 2011, and there is still much uncertainty about what causes CCD, but it is likely that there are a number of important factors at play; for example, mites, other parasites, pesticides, and stress from management activities are thought to be important. Much attention has been focused on the varroa mite, a bloodsucking parasite that attacks both young and adult honeybees. In addition, the mite is also an effective in transmitting diseases. A second mite, the tracheal mite, is also a vector for disease. There is, however, some cause for optimism: mites can potentially be controlled by allowing hives to be ventilated, reducing the use of pesticides may reduce bee exposure, and finding a biological control agent for the mites such as a fungal pathogen could help reduce mite numbers.
WHAT ABOUT WILD HONEYBEES, BUMBLEBEES AND OTHER NATIVE BEES?
Scientists estimate there are about four thousand different species of wild bees that are native to North America. They prefer to nest in thick grass, soil, and wood, and mostly do not make surplus honey or form large colonies. Interestingly, a bee that most are familiar with, the bumblebee (genus Bombus), is dedicated to the three R’s, and repurposes the burrows of mice after their departure for its home. While much research attention has focused on the decline of managed bees and on CCD, we should also be concerned about the decline of wild bee populations. It is likely that some of the same factors that are leading to CCD in managed honeybees are also having effects on wild bee populations—for example, pesticides. Perhaps still more important—as is often the case in ecology—is the loss of the bees’ habitats when natural areas and their flora are transformed during development.
Update: This is indeed a scary situation, but the silver lining here is that the awareness surrounding bees and their plight has led to an increase in interest in beekeeping and the health of bees globally.
A few extra resources:
For an easy introduction to the idea of beekeeping, check out Ashley English's book on the subject Keeping Bees. One of four books in her Homemade Living series, this one is among our favourites! You can pick up your copy from Amazon.
Check back tomorrow as 'Bee Week' continues!