Re: Hygenic behavior in my bees - where did it come from?
Your statement revolves around "hygienic behavior" but you don't define what you mean by the term. There is a gene for hygienic behavior that causes bees to uncap damaged brood. There is another gene that affects removal of dead brood from open cells. If your bees uncap damaged brood but do not remove it, they are not hygienic. There are still more genes that control VSH (Varroa Specific Hygiene). If you are not actively selecting for hygienic behavior, then you are not making much more progress than trying to paddle a boat upstream using your hands as paddles.
If you want mite tolerant bees, stop treating for mites and let the susceptible bees die. Breed from the survivors. It will take about 5 generations to have mostly mite tolerant genetics. Before you do this, try purchasing some mite tolerant queens. It is well worth the cost. I haven't treated for mites in about 6 years now. My bees are thriving.
NW Alabama, 46 years, 24 colonies and growing, sideliner, treatment free since 2005, 14 frame square Dadant broodnest