I don't know how hard it is for large professional beekeepers to avoid diseases and premature death of colonies, but from what I gather those of us who use preventive medicine proceedures faired about as badly as those who did nothing last year. I am sticking by the Apistan ,terramycin. menthol practive with the added step of using Mite Solution during the summer months. It is hard to guess what will happen. I am optimistic that with care and proper feeding to build up more strong colonies this summer for next years production I will probably get through the winter better this year. Also my insulated hive did better than my uninsulated ones in the past.This winter all will get insulation which has now been fabricated.