A newly released report from Harvard claims it's neonics- link attached.
Here is a link that might be useful: Harvard neonic article
I think this is about the 5th "finally explained" article I have seen on this topic. If you read down into the article neonics have been banned in France for five years and they still have CCD so I doubt this is the main problem.
"In contrast, the new study found that long-term exposure to small amounts of neonicotinoids wasn't compromising the bees' immune resistance to pathogens. The hives had just as many infections when they weren't exposed to pesticides. This suggests that "neonicotinoids are causing some other kind of biological mechanism in bees that in turn leads to CCD," scientists said. "
. They're presupposing a narrative and trying to fit the data to it. That's exactly the wrong way to do this. The story goes where the data says it does.
Like the above poster said, they've banned neonictonoides in several countries, and there hasn't been any improvement. That suggests that it's not neonictonoides that are causing it.
They're clearly bad for bees, but I don't think they've got anything to do with CCD.
As to CCD, a couple things are clear - it's hitting commercial beekeeping corporations much worse than its hitting home ones, and its hitting home ones worse than it's hitting feral colonies. My hypothesis is that it's related to genetic bottlenecking via commercial bekeepers frequently requeening from the 2 or 3 major queen producers.
So the food source for bees is now high fructose corn syrup? No wonder they are dying.
There's nothing wrong with high fructose corn syrup in this context.
Fructose in high amounts (like high fructose corn syrup) is bad for humans because our fructose-processing pathway is "meant" to be a minor pathway. It's easily overloaded, so insulin and blood sugar get out of whack.
Fructose from fruits isn't bad, because it is in comparatively low amounts.
High fructose corn syrup now and then isn't bad, because it doesn't constantly overload your system.
People just run into trouble when they drink many cans of fructose-laden soda every day.
But anyway, bees don't have this problem, their processing pathways are different. Honestly, I am not certain what the major sugar in nectar is, but I doubt the HFCS is harming the bees.
In Australia, which has one of the healthiest bee herds in the world and has never reported a case of CCD, neonicotinoids have been in widespread use for over a decade.
So if neonics were a problem, it would be showing up in Australia.
One thing Australia does NOT have is the huge migratory hive business ... and the varroa mite.
I pulled up the atricle and read it. There were no differences between the neonicotinoids and the controls before winter. They feed a 137 ppb solution, or 0.74ng of the neo per bee per day (20% of the LD50) for 91 days in the fall, or a total "dose" of 67ng per bee (20X the LD50). The problem with the study is they assumed the bees were metabolizing the pesticide, when it really just got made into honey which the bees stored to eat in the winter. The dose in the honey likely was 200ppb and there was 20X more than needed to kill half of them.. Pesticide levels in honey and pollen are checked regularly by both the States and the feds, and the 90th percentile (ie highest 10%) was 7.3ppb, so the dose used was 18X the 90th percentile (3X the max detected over 10 yrs). The fact they the fed it for 13 weeks, vs real life of maybe a couple weeks of bloom, the timing (fall when no crops are blooming) and the doses used bring into question the validity of this study for CCD research.