Responding to a number of recent topics and direct queries. Most of the
information is already published, or if unpublished it comes from direct
personal observations or via word of mouth from people I trust would be
truthful. Most of the latter would be considered in a formal court of law
hearsay, so take it for what it is. Additionally, because much of my
information is through friends and others who would stand to benefit
economically (bee and queen sales) from what would appear like an endorsement,
it is better to mention the miracles but not name the saints.  

  

The first colonies with what was considered and then called SMR were
identified close to three decades ago, using single drone inseminated queens
to produce colonies very variable in behavior, but with behavior fixed within
a colony, as much as that is possible. It worked, and a few of those initially
identified colonies actually had mite numbers decrease in standardized field
tests. A Harbo and Hoopingarner paper in 1996 documents this.  

  

For close to a decade it was known that the main effect of VSH/SMR came from
adult bees, not from brood, but the exact mechanism was elusive. Once it was
clearer that this adult effect came from selective hygienic removal of
infested brood, selection continued for that characteristic. The effects of
brood were not tracked or sought. A good number of publications by Harbo and
Harris primarily document all of this, also the paper by Ibrahim and Spivak
referred to recently.  

  

Through various agreements and independent efforts bees with selective
hygienic behavior towards mites have been distributed, shared, and even
identified de novo. There is nothing unique or associated with any particular
lineage, stock, breed, race. Even some of the people involved in this
selection and distribution point out that they are not providing or selling a
commercially useful product, just distributing the genes or sharing the
methodology. Others do sell material of some lineage with the trait
incorporated in it at some level, expecting it to operate well in a high
demand commercial setting. So even this lose coalition of practitioners is not
uniform or tightly coordinated.  

  

In the process of selecting and evaluating these colonies produced through
fairly simple methods (and not part of a gigantic closed population as Oldroyd
calls a true bee breeding and expensive effort) a number of oddities appear,
including some useless material or hopeful monsters. Since removal of brood
obviously requires uncapping, snapshots of brood exposed to hygienic bees
(sometimes multiple subfamilies), can show many "results". Highly effective
and uniformly hygienic bees remove most of the infested brood (particularly if
reproductive) and apparently do not uncap or remove the brood with non
reproductive or no mites. Other colonies uncap, but somehow do not remove or
recap brood. Others uncap and recap pretty much every cell.  

  

Also, it did appear for a while like VSH/SMR colonies had a propensity towards
lower brood production. The cause was never very clear. Some colonies were
definitely very poor in growth with no clear cause. Others actually showed a
seasonal susceptibility to EFB. From what I hear, none of that is an issue in
current material.  

  

At this point, it is thought that highly hygienic and varroa specific colonies
can be produced with very little or no cost to the behavior, such that they
can attain commercially useful populations while keeping mite levels
consistently way below thresholds. And here is where we get into hearsay- all
of the people who have these types of bees out of interest, or for small
economic gain, or with long term plans of scaling it up to mega sales, report
keeping colonies with no treatment. And most do monitor either for VSH in some
form or another, or if they feel VSH is high, they monitor for mites.  

  

Regarding a true brood effect on varroa reproduction, some of us have pointed
out to those running tests for such an effect in naturally resistant
populations in Europe that the effects of brood vs. adults need to be
separated experimentally. Sealed brood has to be protected from actions of
hygienic bees either by screening in the colonies, or removing to incubators.
(And high incubator temperatures can turn most mites non-reproductive giving
the impression of a brood effect....)  

  

In a long and frustrating, maybe not massive enough effort we attempted
selecting for a brood effect on varroa mite reproduction in the early to mid
2010s. Crossing the few best and worst colonies available at the time of
propagation, for seven generations, if I remember.... suggested some possible
progress at first, and then the high and the low lines showed no divergence. I
believe a similar conclusion was made in the 2000s by Rob Page and Gloria de
Grandi Hoffman after two generations of selection. So the topic is there, to
develop, expand on, clarify, just like in the early days of VSH/SMR there were
many things unclear that are now better understood looking back on the rear
view mirror.  

  

  


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