Why did they die?
Why is this year so different? Every day I get messages that say basically the same thing: “I just checked my hive and all the bees are dead. They have plenty of honey and lots of pollen. What did I do wrong?” Some say their bees died in a small cluster; some say their bees were completely gone. Sure, some of this happens every year, but this year seems worse.
I’m just thinking at the keyboard here, so keep in mind this is merely my opinion. But basically, I think two things are converging to kill our bees: healthy mites and unhealthy queens.
Varroa mites first landed in North American in 1987, which is just 26 years ago. It took a number of years before they spread over the entire continent, but during that time they evolved to match North American bees in North American climates. During that period the viruses they carried also evolved to fit the conditions in North America. This is not a stretch; most viruses—as well as many invertebrates—adapt very quickly to changing conditions. Evolution can happen super fast in organisms that have multiple generations per year.
However, some organisms do not evolve quickly and honey bees happen to be one of those. Geneticists have discovered that honey bees have few of the genes that allow for quick adaptation to change. Scientists believe that honey bees use hygienic or defensive behavior—rather than genetic adaptation—to respond to most external threats. In short, you have stodgy adapters being assaulted by a cadre of quick adapters.
The lethal combination of mites and viruses quickly killed off most of the feral colonies in North America, removing a critical part of the honey bee gene pool. No longer able to find sufficient wild bees, beekeepers were forced to import bees from elsewhere. As a result, most of our managed colonies have been raised from production queens that, by definition, have a limited supply of genes. Although beekeepers don’t like to believe it, most of the so-called feral colonies that are discovered today have escaped from managed hives in the recent past. As such, they are only a generation away from their production-queen origins as well.
So while the depth of the gene pool has decreased rapidly due to parasites and pathogens, the need for queens has increased sharply. It makes sense: as more and more hives die, the need for replacement grows. The irony is that the “solution” makes the problem worse.
To meet the demand for replacement colonies, queens are produced in large quantities in the south and shipped all over the country. Through no fault of the producer, these bees have marginal genetics. Why? Because there just aren’t that many genes to pick from anymore. As a result, the exhausted gene pool was spread from sea to shining sea.
And it gets worse. You and fifty other beekeepers in your county have bees with nearly identical genetics simply because everyone in your local bee club bought bees from the same producer. They all arrived in one truck, so in addition to having the same genes, they have the same diseases. It means the drones hanging out in your local drone congregation area have the same genes as well. So if you are trying to raise your own queens to overcome a shallow gene pool, the odds are stacked against you from the start. It’s one heck of a mess.
Now, back to the original question: why is it worse this year? In short, I think it has taken a number of years for Varroa mites and their viruses to adapt and spread across the country. It has also taken a number of years for most of the feral bees to die off and for production queens to replace local queens. What we are seeing now is a crescendo of bad outcomes—a perfect storm. In other words, I think it will get worse before it gets better.
Beekeepers are a creative lot, and I truly believe that many of those colonies were lost in spite of the best beekeeping practices we know. If we are lucky, we will make a discovery that saves the honey bee. But for now, we are stuck with what we have and we don’t know from where the answer will come. Or when. Or if.