The demise of colony collapse disorder
Nothing attracts the press like a doomsday calamity with a scary name. And once they latch on, they can’t let go. Warnings about this particular scourge continue to circulate in the popular press. Meanwhile, Dennis vanEngelsdorp, who helped name the thing, told Wired that he hasn’t seen a case of CCD in five years.
To this day I still get a lot of questions about CCD, but nearly all of them come from non-beekeepers who want to know how to save the bees. I can’t blame these people for being concerned: since the catastrophic nature of the story continues to sell papers, articles about it routinely reappear.
It’s clear that many people don’t understand what CCD was all about because they write to say their carpenter bees died of colony collapse, or the bees that drilled holes in their driveway succumbed to colony collapse. My argument, that those kinds of bees don’t live in colonies, does nothing to dissuade them.
Where did CCD go?
Many scientists spent a lot of time and money looking for something that, in my opinion, didn’t exist. That’s to say, they couldn’t find a discreet causative agent. No smoking gun, like a pathogen or toxin, could be found that linked the dead colonies together. But they were dead, nevertheless.
When you look at history, recurring catastrophic bee losses make a regular appearance, having been called names like spring dwindle, fall dwindle, or some-other-kind-of dwindle. But collapse sounds much more final than dwindle, far more graphic and deadly. But in truth, the total number of bee colonies in North America is rising, not falling, and although honey bees have problems, they are not even close to being endangered.
I became motivated to write about colony collapse after being interviewed by a 13-year-old student from Seattle. Isabella had some prescient questions about CCD, so I decided to tell you what I told her.
The perfect storm
It is my belief that what we call CCD was a confluence of factors that all came together in 2006, the year CCD was “discovered” and named. Some commercial beekeepers lost many colonies that year, and indeed it was a devastating blow to them. I don’t want to trivialize their losses.
But rather than being from a single cause, I believe that four important factors were at work. These four factors reinforced each other to create a perfect storm of honey bee loss. In no particular order, these were:
- Viral diseases mediated by Varroa destructor
- Poor honey bee nutrition
- High background levels of pesticide
- A shallow gene pool created by mass-produced queens
Indeed, other factors may have been involved. But in my mind, these are the big four that could come together again at any time and cause another so-called beepocalypse. All of these issues have been studied extensively since 2006.
We now know that viral diseases are the real issue behind varroa mites, and that the diseases seem to be getting more powerful as time goes by. Then too, the number of viral diseases in individual colonies seems to be increasing.
Malnutrition in honey bees is on the rise, not only because of urbanization and monoculture cropping, but also because of the wanton use of herbicides. Herbicides not only destroy flowering plants but they open the door to invasive species. Invasive species decrease the floral diversity of a region, which decreases the total number of days with flowers and the total number of flower types on each day.
Although many people want to point a finger at a particular insecticide group, I believe the bee problem is actually due to a high background level of pesticides in the environment—pesticides of many different classes and modes of action. Until we are willing to live with a few more “pests” in our lives, insecticides will continue to wipe out bees, just as they have devastated other beneficial insects and friendly bugs like fireflies.
Most of the queens shipped throughout the United States are produced in a few areas of the south. These queens are naturally adapted to the south and, I believe, poorly equipped to deal with northern climates. In addition, because so many queens are produced in small areas, the genetic pool is shallower than it would be if queens were developed locally. These days, queens typically last a year, if that. In the “old days” queens lasted several years—sometimes as many as five. It seems we have sacrificed quality for convenience, and it has become commonplace for beekeepers to re-queen annually. How sad.
Will CCD reappear?
I think that something like CCD could reappear at any time. It might not look exactly the same and it might comprise a different assortment of causes. Although we have learned a lot about honey bee health since the appearance of CCD, we haven’t solved any of the problems. If anything, most of the underlying issues have only gotten worse.
I should also note that some researchers continue to believe that a pathogen is responsible for CCD and they cite some compelling reasons. For example, many beekeepers reported a return of CCD when they reused equipment from dead hives. Others reported that scavengers were slow to invade hives after the colony died of CCD. Still, some of the best scientists in the world hunted for years but found nothing.
My session with Isabella reminded me that even if CCD did not have a single discreet cause, it was still a thing, and one that could recur. I went into the interview thinking I would disabuse her of the notion of CCD but, because of her questions, I came out of the interview convinced CCD—or something like it—could happen again. Only time will tell.
Honey Bee Suite