Dead of winter in Illinois, I have two hives, one has many dead bees on platform and outside of hive along with hundres of brown trails which I assume is from clensing and the other no spots and few dead bees. yet both are alive. I am curios as to why they seem so different. What is the best emergency feeding method to use if need be? 50 degrees today and I will check both.
Brown stains/trails on the exterior of the hive is indication of nosema/disentery. If they are strong enough, this will clear up come spring when the weather gets better. If they are not, you could consider treating then with Fumagillan in sugar water if you have access to it.
Some have also claimed that cider vinegar helps as well. I have no experience with using cider vinegar on hives showing symptoms, but have tried it as a preventative measure.
Interesting, how would you introduce the vinegar? Is it sprayed on or mixed with sugar syrup to be eaten by the bees? I am curious.
You put a little in the syrup you feed spring and fall. I've heard of others doing it, though no information on "use a tablespoon per quart" or anything.