Hello Blane & All,
> Apis cerana is considerable smaller than Apis mellifera and varroa
continues >to infest cerana and is able to reproduce in cerana combs so why
do we >think it will not be able to reproduce in combs with cells that are
still >somewhat larger than cerana cells?

The parasite / host relationship between cerana and mellifera is not the
same. Varroa has NEVER been found to reproduce in cerana worker cells
anyplace in the world.   At least that was true when the Varroa Handbook was
written.
Varroa is at a big disadvantage with cerana and natural mite reduction takes
place when periods without drone raising takes place.  Because cerana and
mellifera are very similar bees but are different enough they can not cross
why does not varroa reproduce in the small cerana cells.  Is small cell  the
answer or other unknown factors. When I first read the above I wondered to
myself if small cell size *might* be a IPM control method.  Researchers
suspect something different in the Juvenile growth hormone of cerana BUT the
question remains unanswered.  I still believe if research funds are
available small cell size should be looked at along with finding out exactly
why varroa can not reproduce in the small cell size of cerana.
Sincerely,
Bob Harrison
Odessa, Missouri
Ps. Open mating could reduce the effectiveness of both the Russian and the
SMR lines.  Glenn Apiaries is at least reporting varroa resistance in the
first round of open mated stock. It will take several years to get the true
picture.
Although I am experimenting with the SMR stock I will have to wait a couple
years to say "we have got the answer to our varroa problems!"