I have lost nucs that later got slimed by SHB, but what happened to me yesterday was the worst event in my 6 years of beekeeping. I had a 2 deep 4 super hive that came out of the winter very strong (in 2 deeps and 1 super). I kept adding supers to prevent them from swarming, rather than split the hive. Well, they swarmed about a month ago at least once. Upon inspection I saw opened queen cells, so I knew there was a virgin queen. Maybe they swarmed again, not clear, and 2 weeks ago I looked at every single frame: there was no brood, no larvae, but 2 deeps and 1 1/2 supers full of capped honey. I was certain thar a virgin queen was there. A week ago I put fresh vegetable oil in the pan underneath the screen bottom board, who was mostly empty of SHB but had the usual debris. Yesterday I checked on them again, a month after their pressumed swarmed date, giving all the extra time for the queen to begin laying. Weather was in mid 80 in the past 2 weeks. Well, as you might have guessed by now, the bees absconded, and the hive was slimed with SHB larvae, making a river of maggots between the frames. The deeps were completely gone: 20 frames slimed. The 4 supers were also slimed, but I think I can salvage their comb. I put what I could in the freezer (I have a moderate size one), dumped as many maggots as I could on a tarp and with a flat piece of wood, I pressed and killed as many as I could and put the 20 deep frames with maggots in plastic trash bags. This morning I realized that the birds ate most of the dead maggots, but also noticed maggots coming out of the trash bags: apparently they chewed tiny holes and then they came out on a line. I added a second layer of trash bags and put them in a sealed airtight trash container for now. The plan is to freeze them, a few frames at a time, and then decide if I can save any comb, or just remove the comb and save the frames. I suppose another idea is to cut the comb from the frames and burn it all.
It took 3 hours per person for my wife and me to clean up this mess. The hive was in my backyard. All it took was one week of unoccupied by bees (though robbers came in and out) for the SHB to completely destroy so many frames and about 110 pounds of honey. I had another hive swarm, but luckily it requeened itself and has no SHB pressure. Swarms are common in the south, for hives that come out of the winter strong. I guess in the future I should split any strong hive in two (walk away split) in the spring, and let one part make a queen, before they even build queen cells. But even so, the SHB problem is there: we are still in May, with temperatures in the 80s and a hive unoccupied for a week (with screen bottom board and oil tray) can collapse in such a way.
It is so disappointing to loose such a hive, such bees (feral survivor stock), 110 pounds of honey and so many frames of brood.
I wish we could find a better way to control SHB. I really hope my experience is not common among beekeepers in the US south.