varroa mites

A bit more about VSH

A reader asked how the VSH bees detect mites within the cell. So far, I cannot find a detailed explanation. Many scientific papers discuss various aspects of mite removal and efficiency, but the ones I read didn’t answer this specific question.

Varroa sensitive hygiene was originally discovered by the USDA Honey Bee Breeding, Genetics and Physiology Laboratory in Baton Rouge, LA. After discovery of the trait in nature, they bred lines of bees with amplified hygienic behavior. According to the USDA, VSH bees only remove pupae infected with mites that have begun to reproduce; they do not remove pupae with mites that are not reproducing or that are sterile.

The USDA online literature says the bees “sniff out” reproductive mites but it doesn’t say more than that. According to Glenn Apiaries, a company that sells VSH breeder queens, VSH bees also show activity against tracheal mites, American foulbrood, chalkbrood, wax moths, and small hive beetles.

Based on that information it sounds as if the VSH bees are recognizing all sorts of wildlife that doesn’t belong in the hive. Odor is the most likely mechanism, but so far I haven’t found a specific citation.



  • Thanks for looking into this Rusty. Extra fascinating that they know when mites have begun to reproduce.

    Maybe the more mites there are, the more different the larvae smells? Or perhaps the larvae start to give off a distress signal smell in response to having these horrible vampire mites sucking on them.

  • I have VSH bees, and as you may have read, Rusty, the queen expresses two recessive genes that result in a type of behavior – “varroa sensitive hygiene behavior”, if you will – in which they conduct the kind of housekeeping you describe. I also have not read anywhere that they have a definitive answer for what environmental trigger prompts the behavior itself, but clearly the existence of the recessive genes creates some innate sensory ability to detect the mites. I am assuming that since the bees react strongly to pheromones and chemical signals, that something in that ballpark is the prompt, but I don’t know. I do know that I had no mite issues last season (my first) and see nothing so far this season. So far at least, they seem worth the trouble to avoid using pesticides in the hive.

    • Hello Michael. You posted here in April 2013 about having VSH bees. Just wondering how your bees are going since then? Have you had to use treatments in your hives since then? I am a beekeeper on New Zealand and we are all looking for mite resistant bees so I am curious as to how you are going? Too many people say that have mite resistant bees but I have yet to see it in the ‘Real world’. Thanks

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