What Are VSH (Varroa Sensitive Hygiene) Bees?
VSH (Varroa Sensitive Hygiene) is a trait in honeybees that enables a colony to survive without mite controls. The VSH trait causes VSH hygienic behavior, which is the removal of mite-infested cells from the brood nest. This VSH behavior serves as a natural and physical check on the varroa mites’ ability to reproduce and expand their population inside of a beehive. VSH is not a unique race of bee, rather it is a behavioral trait that can be bred into any stock. Wildflower Meadows produces VSH-Italian queen bees for sale, but any race of honeybee can express the varroa sensitive hygiene trait, such as Carniolan, Russian, Caucasian, etc.
The VSH trait is not necessarily linked with the overall performance of a beehive, rather it is only a measurement of mite resistance. Bees that are 100% VSH can be very good colonies or very poor colonies, as other aspects of a colony’s performance, such as brood production, honey production or even temperament, are all independent of the VSH trait.
The VSH trait is an additive trait. This means that varroa sensitive hygiene queens that are naturally mated to unselected drones will still produce the VSH trait in their offspring. Even though the offspring may not have all of the VSH alleles (an allele is a variation of a given gene), a percentage of the VSH trait is passed on to the next generation, thus resulting in an improved level of mite resistance, which can sometimes even be equal to bees that have 100% of the VSH alleles.
VSH hygienic behavior is expressed on cells that have been capped for four to six days; in other words, young capped brood. VSH bees will either pull or eat mite-infested pupae from the young brood cells, resulting in the death of the immature varroa mites that are present in the cells.
At Wildflower Meadows, our breeder queens contain 100% of the VSH alleles, which we insure through instrumental insemination by crossing 100% VSH queens with 100% VSH drones. The offspring of these breeders naturally mate with our most desirable and productive VSH-Italian drones, resulting in Wildflower Meadows’ VSH-Italian queen bees.