Bee Detectives Needed!
I'm writing this on behalf of my father in-law who received a nuc of bees as a retirement present last year.
Everything started off well. The hive seemed to be thriving. It grew quickly, and he was able to add a honey super which, by late fall was 6/8 frames full of capped honey.
He was nervous about the winter though. And upon our inspection a week or so ago, he was right to be. It was a total hive collapse. Not a single living thing to be found, and now everyone is sitting around wondering what went wrong. This is where I'm hoping some bee detectives on reddit might be able to make sense of the situation.
Here's a few pictures to aid the below text: https://imgur.com/a/d4aMsjm
-Hive is located in Central Ontario
-Before winter, bees were feed a large amount of sugar water, enough that they stopped eating it
-Hive was properly insulated and the 6/8ths full honey super was left on without the queen excluder for winter sustenance
-Upon inspection this spring, the honey super frames were completely untouched
-Brood chamber frames were emptied of all eggs and larvae, but honey was untouched
-Almost all the dead bees I could see in the hive had been decapitated?
-There was what appeared to be a swarm of dead bees about 1m away from the hive under some roots
-The one crucial thing that wasn't done last year was any treatment for mites, is this the sole reason for collapse?
-Did the hive get infiltrated by another colony?
-Was the insulation put on too early and the bees overheated?
Any suggestions for leads to follow in this macabre mystery are greatly appreciated.