QUOTE: U.S. Department of Agriculture (USDA) scientists hope the population of Varroa mite-detecting honeybees could potentially improve the health of the overall honeybee population.
Some bees have a low-frequency genetic trait termed varroa-sensitive hygiene (VSH) that enables them to better locate and remove varroa mites from hives. These bees team up to open the covered brood cells and remove the mite-damaged pupae and any accompanying varroa mites from the hive.
Scientists think they're much better at smelling the odors associated with varroa-infected cells.
Entomologists have now developed a population of honeybees with a high expression of the VSH. In a field trial of 40 colonies, those with the highest levels of VSH showed significantly lower mite infestation and bee mortality than the control groups. The study results were published in the Journal of Apicultural Research.
Not meant for mass reproduction
VSH honeybees aren't meant for mass reproduction as a pure stock, since that would result in excessive inbreeding, with single queens mating with up to 20 drone bees.
The VSH trait expresses infrequently in the wild and some stocks, such as Russian honeybee, have developed some mite-resistance naturally over time.
It's important weigh the pros and cons of selectively breeding for traits versus promoting more "hybrid vigor" by allowing queens to mate of their own accord.