I've last 3 hives in 2 weeks. All 3 were swarms from April. I check my hives regularly, but I don't know what I'm missing. All three hives when I noticed were gone had no bees, stores, or honey. The last one had SHB larvae, but no SHB walking around. There was wax moths, but no evidence of brood diseases. There was no capped brood, eggs or larvae. There was stores 3 weeks ago, as well as eggs, queen, and open and capped brood. I know sometimes hives just die, but the best way to learn is to understand why and then prevent. I did treat with OAV All my hives 3 weeks ago, I have 25 more that were treated and lived