Fact No. 1: Bees are responsible for pollinating at least a third of our food crops.
Fact No. 2: Honeybees, in particular, are disappearing at alarming rates.
In light of the fairly recent furor about whole colonies of honeybees suddenly disappearing from their hives, you may be surprised to learn this phenomenon has been reported in the U.S. as early as the late 1800s.
Granted, it was an infrequent occurrence. Back then, and up until recently, people called it by a number of names: spring dwindle, May disease, fall dwindle disease, autumn collapse … or simply “the disappearing disease.”
It was thought the reason(s) could be attributed to bee pests, diseases, urbanization, climate change, or pesticide use.
Back in the 1940s, large losses of colonies were reported in the U.S. They were attributed to a pathogen called Paenibacillus larvae which causes American foulbrood (AFB) — deathly harmful to larval honeybees. Luckily, antibiotics have helped tremendously in controlling it.
Mites are another huge problem to honeybees. Tracheal mites (Acarapis woodi) were first detected in U.S. bee colonies in 1984. Female mites attach their eggs to the tracheal tube walls of young bees. The young mites feed on the fluid of the bee’s circulatory system. Super small, there can be more than 100 mites in the trachea of a single bee — effectively weakening the bee.
Another mite problem is the vampire mite or Varroa destructor. Native to Japan, this mite infected European (or Western) honeybees that were imported from Russia in the early 1960s. The infected bees then re-infiltrated eastern Europe throughout the 1970s.
Between 1971 when Brazil discovered their bees had the vampire mite and its appearance in Papua, New Guinea in 2008, every country in the world has succumbed, except Australia.
So far, this Varroa destructor has been largely blamed for what has become termed as Colony Collapse Disorder (CCD). This is certainly the viewpoint of one Australian biologist, Dr. Dennis Anderson, a world-renowned expert on honeybees.
However, new studies are pointing towards insecticides, particularly those containing neonicotinoids, as the potential culprit. This class of insecticides acts on the central nervous system.
One such is Clothianidin, which is absorbed by the plant and released in its pollen and nectar to kill insect pests. There has been some speculation this product may be responsible for large numbers of honeybee deaths.
The alarm amongst the agricultural community in Europe was so great Germany was prompted to ban its use on May 15, 2008. But on this side of the Atlantic Ocean, it is another story.
The Environmental Protection Agency (EPA) granted conditional registration for use of Clothianidin for pesticide use in April 2003. The Canadian Food Inspection Agency granted registration for use of Clothianidin in September 2004.
Clothianidin is used to treat corn, canola, sugar beet, wheat, soy and sunflower seeds before planting.
Some scientists claim honeybees pick up this pesticide from the permeated pollen and nectar of treated plants and carry it back to the hive. From there it is spread amongst the other members of the colony.
Yet another reasonable theory behind CCD could be the increased leaning towards the farming of large tracts of monoculture crops. Bees were specifically designed to pollinate a variety of fruits, vegetables and native plants.
Loss of diversity within their home range could certainly be a contributing factor towards their eventual demise.
When you look at the whole picture of a bee’s environment from the bees’ point of view, perhaps we should own up to the implications of our activities towards their very existence.
It may be one reason, or many, why whole bee colonies are disappearing. Whatever the cause, we’d best look to improving their situation. And soon!
Fact No. 3: The estimated total value of honeybees to Canadian agriculture is about $782 million.
That’s a lot of food.
Leslie Cox co-owns Growing Concern Cottage Garden in Black Creek. Her column appears every second Friday.
