Since ~2006, honey bee colonies in the US have been dropping dead overnight. Literally. They call it ‘colony collapse disorder’. While large populations of organisms dying is disturbing, no matter the species, we need honey bees– they help pollinate so many of our crops. I grew up in the banks of the Missouri River, around apple and peach orchards (who always had their own bee hives, and honey) and hell, I eat everything on that list…
What is killing our bees?
People have accused GMOs and wireless internet and pesticides and antibiotics… We didnt have a clue before.
It might be viruses. Maybe.
Okay, so we have looked at what is going on in bee colonies that are failing. Weve looked at what viruses/bacteria/fungi are ‘normal’ in thriving bee colonies.
This latest paper suggests that it is a virus that is normally found in healthy and collapsing colonies.
… But if the virus is in both populations… how can it play a role in CCD?
It could play a role in CCD because viruses are not clones of one another.
Think about it! Look at me! What do I study every day? VIRAL EVOLUTION. Two people can be infected with ‘HIV-1′, and one could be dead in a few years, the other live out their natural lifespan. Part of what leads to differential disease progression is what version of ‘HIV-1′ they are infected with.
Same thing with honey bees and deformed wing virus (DWV), apparently.
Think of it this way– ‘Normal’ honey bee colonies have a lot of different circulating variants of DWV. Think of those variants as a bag of Skittles. Lots of flavors, fairly equal distribution.
Viral diversity in collapsing colonies, on the other hand, is like buying a bag of Skittles, and theyre all lime. All of them.
You would be like “WTF happened to the diversity???” Thats exactly what these scientists said when they found a bunch of one kind of DWV in CCD.
Apparently (again, we might totally be off on this, we dont know whats going on), there is a mite population that is spreading DWV around. DWV is normally spread from bee to bee via oral and sexual routes, and like 10% of the population is DMV positive (with not a lot of negative effects). These mites act like little IV drug users, going around infecting all the bees they feed on– almost 100% of the bees are infected with DMV in collapsing colonies.
But wait, theres more– It looks like there is some kind of selective pressure on the virus, something about being transmitted via the mite, that is causing all of the other flavors of virus/Skittles to disappear. The mites are selecting ‘lime’ DMV, infecting all the bees with ‘lime’ DMV, and ‘lime’ is killing the bees.
What is also super interesting in this paper, is that it was done in Hawaii. Why is that cool? Cause the islands are isolated from the rest of the world, and isolated from one another. This means these scientists could *see* the DMV viral diversity go down, in real time, and compare island to island, which helped them figure out a time-lag between the mites being introduced to the population, and initiation of collapse. Which explains why other groups who had looked for an association between the mites and collapse might not have seen anything– their timing was off (it takes the mites and virus time to reduce the viral diversity from ‘Taste the Rainbow’ to ‘lime’.
Anyway– Super cool paper. But do we *know* what causes colony collapse? Do we *know* what to do about it yet? Nope.