How Colony Collapse Disorder Works

Honeybees are social creatures, one of the reasons they're ideal pollinators for commercial beekeepers. They're relatively easy to transport and manage, and they aren't too picky about where their nectar comes from, so they can adapt to pollinating many plants.

However, the job of beekeeping is tough. There are several factors that can complicate the rearing of honeybees. For example, mites and fungi can infest a hive and cause health-related problems for the bees. It can be expensive and challenging to provide bees with all the proper nutrition they need, especially as foraging land becomes scarcer.

Bees can also give their beekeeper a nasty shock when they go missing from their hives. Regular attrition rates are always present in hives and usually peak in winter (generally up to about 20 percent is normal), but Colony Collapse Disorder is on a whole other scale [source: Barrionuevo].

According to the USDA Agricultural Research Service, Colony Collapse Disorder may have been present in the U.S. as early as 2002, although it wasn't until 2006 that the numbers hit a fever pitch. Between October and December 2006, U.S. beekeepers saw their hives failing at rates much higher than the normal yearly turnover. Of the affected beekeepers, some 30 to 90 percent of their bees were dying. Between September 2007 and March 2008, U.S. losses were estimated at about 36 percent of managed hives [source: Science Daily].

Colony Collapse Disorder is characterized by the inexplicable absence of the majority of a hive's bees. Sometimes the queen, larvae and a few younger bees are still present, along with the colony's honey and bee bread (a combination of pollen and nectar), but the rest of the community is absent. An empty hive can be hot real estate in the insect world, especially if it's full of honey. But other insects, like moths, beetles and other bees that would typically leap at the chance to become the new tenants of a beehive, avoid CCD colonies for at least a few days. So what's happening to these vanishing bees?

This recent outbreak of CCD is not the first time bees have pulled a disappearing act, but it's the most severe and widespread. First noticed on a large scale in the U.S., cases have since been reported in other parts of the world like Europe. Although Australia has had trouble with CCD, the year 2008 turned out to be normal for beekeepers. CCD could spell disaster for the agriculture industry because of its reliance on honeybees as pollinators. Many industry leaders and researchers are looking into alternatives in the event the worst should happen and bees are no longer viable agricultural pollinators.

So what's making some bees fly off to greener pastures (or, more likely, fly off to die)? That's the million-dollar question that researchers and apiarists (beekeepers) are trying to answer. On the next page, we'll look at some of the possible causes of CCD.

Researchers have sifted through the list of possible Colony Collapse Disorder causes extensively during the past few years and haven't come up with one definitive answer. They have a few promising leads, however, and several factors yet to study.

At this point, the evidence seems to be leaning to the theory that CCD is caused by a couple of factors working in tandem. Here are some of the suspects who might share responsibility for Colony Collapse Disorder.

Other factors under the magnifying glass include the chance that other (possibly unknown) pathogens or microorganisms are involved, or that honeybees might be lacking in genetic diversity. Some people have proposed that genetically modified crops are to blame, but this idea isn't high on the list of likely causes. One theory -- that cell phone and cell tower radiation are the culprits -- has been ruled out.

While it seems like there's a perfect storm of dangerous elements descending on bees, what makes matters worse is that bee populations frequently come into contact with one another. Some beekeepers try to keep their colonies isolated from other hives during pollination events to prevent any dangerous exposure from ailing hives.

So now that we've looked at some of the factors that could be causing Colony Collapse Disorder, let's take a look at what's being done to find some answers.

Commercial honeybees seem to be at the greatest risk for contracting CCD. Declines and hive abandonments have been noted in other bee species as well. Researchers are comparing healthy hives with CCD-affected hives to try to determine what's causing the phenomenon.

In addition, agriculturalists, apiarists and scientists are trying to find a replacement for the honeybee as the premium pollinator. They're looking to see if other species of bee, like the blue orchard bee, can be primed for the task.

As research progresses, it's becoming clear that while there may still be one elusive culprit behind CCD, it's likely caused by a combination of factors. Because of this, finding an answer becomes a puzzle, as researchers struggle to discover the balance of factors that causes the fateful abandonment of a honeybee hive.

Scientists are toying with some tentative ideas to battle CCD. For example, if IAPV is a major factor, then the curious fact that some bees seem to have incorporated the virus' DNA into their genetic code and developed immunity could point the way to a solution. Immune bees could be bred with other bees, creating a population of protected hives. On the other hand, this could be how the virus causes CCD in the first place, so the idea still requires extensive testing to see if it's a viable option.

Some regions have banned the use of neonicotinoid pesticides to protect bee colonies. Whether this ban will solve the problem has yet to be seen. Researchers are finding a bevy of chemicals within beehives -- everything from crop pesticides to miticide treatments -- which may be interacting in harmful ways.

Researchers say more samples from around the world are needed to nail down what's causing CCD. For now, beekeepers can best care for their hives by ensuring their bees get all the nutrition they need and aren't being bothered by mites. Some beekeepers may want to minimize the impact of stress. Strategies for reducing stress may include finding better off-season foraging ground and decreasing travel.

Want to learn more about bees and other insects? Continue to the next page and visit the links.