Re: Tracheal Mites
BeeKeeping in Tennessee, University of Tenn. Ext. Service, PB1745:
"Treatments for Tracheal Mites:
Resistant Stock: Recently, several newly developed genetic stocks of honeybees have shown some resistance to the effects of tracheal mites. This resistance is not 100 percent; however, research indicated significant improvement when compared to non-resistant lines. One stock, the BUCKFAST bee, can be purchased from Weaver Apiaries in Navasota, Texas. Additional stocks of the “Yugo” bee, tested
by the USDA, have been released to queen producers to breed and sell. The New World Carniolan stock
is also reported to express partial resistance to tracheal mite. Some queen producers are advertising “resistant” bees. We do not know whether these stocks are resistant or not; therefore, beekeepers should
be careful when purchasing stock that claims to be resistant. It still may be necessary to apply additional treatments as explained below."
You might try requeening to resistant stock, or run a search on this forum for current treatments. Sorry for your loss.
"I only regret that I have but one life to lose for my country." Nathan Hale, 1776