Courtesy Rainer Hungershausen, Flickr.

The topic of disappearing honey bees first cropped up in 2004 and by the spring of 2007 was all over the news. Thousands of commercial beekeepers across the U.S. and beyond were reporting in some cases that as many as two-thirds of their honey bees were flying away from their hives, never to return. What made the problem”"dubbed “Colony Collapse Disorder” (CCD)”"so unusual is that most traumas to bee colonies leaves bees dead in or around their hives, not mysteriously gone altogether.

Strangely enough, there was no concrete evidence pointing to disease or predation or of mites that tend to attack bee hives. Some beekeepers reported that moths, animals and other bees were steering clear of the newly empty nests, leading to speculation that chemical contamination due to widespread use of pesticides might be to blame. But no smoking gun emerged and the mystery remains today.

According to the U.S. Department of Agriculture’s Agricultural Research Service (ARS), which last year convened a multi-agency steering committee to assess the problem and find solutions, several factors could be combining to cause CCD. “Pesticides may be having unexpected negative effects on honey bees” reports ARS, adding that as yet unknown parasites, pathogens or viruses could also be wreaking havoc on bee colonies. Studies have also indicated that poor management of populations of commercial honey bees”"including inadequate diet and long distance transportation”"may play a role.

In one study, researchers from Columbia University isolated the presence of a virus”"the so-called Israeli Acute Paralysis Virus”"in upwards of 96 percent of the hives studied that were affected by CCD. Other studies point to widespread use of Imidacloprid, a common grub-control chemical used on lawns and farms and which has already been banned in France due to its alleged effect on bees. But finding a single cause of CCD seems unlikely, and ARS researchers point to the possibility of “a perfect storm of existing stresses” weakening colonies to the point of collapse: “Stress”¦compromises the immune system of bees”¦and may disrupt their social system, making colonies more susceptible to disease.”

Whatever the cause, CCD remains a real threat to agriculture. About a third of all American farm production is dependent upon the pollination efforts of commercially-raised honey bees. While diversifying the stock of insect pollinators beyond just one species of honey bee would certainly represent a step in the right direction, re-jiggering the nation’s agricultural system represents no small challenge.

Not surprisingly perhaps, organic beekeepers have not experienced CCD, leading to speculation that overall greener management practices could be the answer even if direct causes are not determined. Meanwhile, efforts to genetically modify bees that are resistant to predators and pathogens could also prove fruitful, although such high tech solutions are still untested and could open up other cans of worms.

The SafeLawns foundation and the Toxics Action Center are up in arms over a Worcester city proposal to spray more then a million gallons of the insecticide Imidacloprid over a million acres to combat an out of control Asian longhorn beetle infestation in the area. The problem, the groups say, is that Imidacloprid is linked to colony collapse disorder in bees and is toxic to aquatic life earthworms and birds, according to a recent study completed in the UK.

Imidacloprid is a synthetic form of nicotine. On September 16 the Pesticide Board Subcommittee of Massachusetts will rule on whether to go through with this soil drenching plan. Imidacloprid has been banned in France and Germany as a soil drenching agent and a recent study done in England recommends it be banned there as well.

“Certainly the Asian longhorn beetle is a devastating problem and no easy answers exist. Drenching your soil with this toxin, however, is most certainly not the solution” said Paul Tukey, founder of The SafeLawns Foundation. “It’s imperative that this Worcester proposal “" which calls for three times the EPA recommended amount of imidacloprid to be applied “" be declined. The impacts on bees, the soils and the watershed of that region could be devastating.”

The SafeLawns Foundation, based in Washington, D.C and the Toxics Action Center, based in Boston, plan to team with other environmental organizations over the next few days.

The recent British study that links imidacloprid to colony collapse disorder, said Tukey, creates an even greater sense of urgency. Colony Collapse Disorder, by some estimates, has killed nearly a third of the nation’s honeybee population since 2006.

“This is the most comprehensive review of the scientific evidence yet and it has revealed the disturbing amount of damage these poisons can cause” said Matt Shardlow, chief executive of Buglife, the non-profit organization that commissioned the British study.

A safer and cost-effective technique to combat the Asian longhorn beetle, said Tukey, involves injecting affected trees. That reduces the amount of toxin used and generally contains any poisons to within the tree. When applied as a soil drench, the material can seep into surface and groundwater, or be taken up directly by birds, pets and humans. A Massachusetts company known as ArborJet of Winchester pioneered the injection technique that is now considered to be the USDA standard treatment for several exotic invasive tree pests, including the Asian longhorn beetle.