>From sci.agriculture.beekeeping:
---
FYI, I recently received this e-mail from a USDA entomologist regarding
inheritance of Varroa and Tracheal Mite resistance traits:

>How resistant to varroa are Russian outcrosses?

"I think it depends on the outcross. Some are and some are not at all
resistant."

>Is resistance dominant in half-breeds?

"No, in the best case the out crosses would be somewhat resistant. But, I
know of at least one cross where the domestic susceptibility is dominant."

>I ordered open-mated, full blooded Russian queens this spring.  So far, I
am very pleased with the results.  Bees that get mites on them vibrate and
jump around until they get attention from the others.

"That is good. It suggests that they may be at least somewhat resistant."

>In your opinion, what races of bees are the most resistant to tracheal
mites?

"The darker bees from northern Europe generally are more resistant to
tracheal mites. However, many US bee breeders are trying to improve their
stocks for tracheal mite resistance.  The genetics are rather simple for tm
resistance, so those that try to improve their stock can do so rather
easily. "

--
Ed

http://www.geocites.com/RainForest/Canopy/1436/