On 9 Dec 97 at 22:48, Vince Coppola wrote: > I agree with David on this one. Andy's statement is poor advice for > anyone wintering bees in the north. There is plenty of data on the > affect of T-mite and not to treat is foolish. Before treating our > losses were as high as 55%, treating got us below 25% and breading > for resistance has almost eliminated losses to T-mites. It is very possible that Andy's advice forgets the necessary temperature controls of the winter cluster. Dr. Nasr has done a great deal of work on "Thermal Regulation"and this explains why Northern bees die with T-mite infestations, whereas Southern bees do not. It seems the cluster regulates the internal temp by increased oxygen uptake. Obviously if the bees trachae are blocked with mites they cannot absorb enough oxygen to keep the cluster warm under our low temp conditions. This accounts for excessive winter kill due to T-mites in the North. We have been in the Ontario Breeding for 4 years, and when we first started to test and select for T-mite resistance we were finding up to 250 mites per bee. Now by selection and breeding we have reduced that to no mites or figures like .25 mites in 50% of bees tested. Well below the economic threshhold. In other words, at these figures there is no need for treatment or loss to T-mites. Worthy of comment? ******************************************* The Bee Works, 9 Progress Dr, Unit 2, Orillia, Ontario, L3V 6H1 Phone/fax 705-326-7171 David Eyre, Owner. http://www.muskoka.net/~beeworks e-mail <[log in to unmask]> ********************************************