Peter said: > After a few years of this, I realised that I was on a treadmill > and decided to allow susceptible colonies to die and to breed from > those that survived. The problems rapidly disappeared and I have > not bothered to look for either acarine or nosema for many years. I don't understand the logic. a) Nosema is a disease that can reduce yield per hive without showing any overt symptoms. b) Ditto for tracheal mites. c) While serious cases of either are easy to notice, my understanding has been that it is the "mild" cases that are the real problem. d) One cannot control that which they do not measure, and you certainly cannot find that which you don't even try to find. So how do you KNOW your bees don't have nosema? Ditto for tracheal mites. At the TN State beekeeper meeting last weekend, Dr. Tom Webster of U. Kentucky gave a VERY insightful presentation about nosema, making the drive from Virginia worthwhile. In short, he looked at the usual "check the midgut" test for nosema, and found it to be misleading when compared to microscope examination for the actual nosema protozoa. He strongly suggests that a microscope be used to check for nosema, as he found that sampled bees that "looked ok" to the naked eye had serious counts of the nosema protozoa, while some bees with classic discolored and inflated midguts had far LESS actual protozoa - almost none in some cases. I had never heard anyone suggest this before, and feel that he has made an important observation. The bad news is that protozoa are just plain hard to see. He mentioned "phase contrast", a microscope feature that is well beyond the budget of a beekeeper. >>I<< don't even have phase contrast condensers or objective lenses, and I like high-tech toys. As it will be warm (in the 70s!) tomorrow, I will be sampling a few bees from a few hives for examination for protozoa, and I will try various tricks with everything from my son's 100% plastic $20 "chemistry set" microscope up to the really nice one I liberated from AT&T Bell Labs at their annual "yard sale". If I can come up with an approach that works with inexpensive microscopes, I'll report on it. Maybe I don't have a nosema problem, but I'm sure as heck gonna look before it gets too cold to feed some Fumadil. jim :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: -- Visit www.honeybeeworld.com/BEE-L for rules, FAQ and other info --- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::