06/22/2026
Genetic testing for mite resistance.
We are testing for mite resistance in our experimental “Harbo yard” (named after USDA bee researcher John Harbo. Which we hope will one day dominate the mating areas and flood the genetic gene pool with incredible genetics so that one day, our queens will be able to open-mate in the wild and pick up those genetics and be mite resistant. But there are only 60 allele combinations that expressed varroa sensitive hygiene (VSH) so not all bees carry it. A score of 0 means there is no mite expression and a 4 means the colony carries all the alleles for mite resistance.
But I’m also testing and recording a few more things as an Urban Beekeeper who has unknown apiaries and sketchy neighbor beekeepers who don’t take care of their bees, creating mite pressure and mite bombs on our hives. So I’m testing for Harbo scores every month I can as the season allows, as well as taking mite washes on each colony to assess the amount of mites “walking in the front door.”
1) as mite pressure increases (June-August) does a high scoring VSH colony’s score decrease and then recover once pressure is lowered again?
2) Can a low scoring colony INCREASE their score as mite pressure in the apiary is decreased over time?
4) Do high scoring colonies scores dip down and then recover back to normal during high mite pressure areas, or do they stay consistent as they power through the challenge.
5) Just how quickly does a colony that scores a 4 turn to absolute trash as they requeen themselves and those daughters open-mate? One generation? Two generations? Never?
Maybe THIS should be my Master’s project for the Colorado State Beekeeper’s Master Certification Program?
Follow along as we get super nerdy with it.
