I'm not making a testimonial as to the effectiveness of FGMO for treatment
of mites at this time.  But I would like to offer some thoughts on the
delivery method I've been using.  Basically, it is nothing more than a
standard grease patty with FGMO substituted for 50% of the Crisco
shortening, and powdered sugar substituted for 25% of the granulated sugar.
The recipe for 3 pounds of mix is as follows:
 
3 cups (1 1/2 lb) granulated sugar
2 cups (1/2 lb) powdered sugar
1 cup (1/2 lb) Crisco
1 cup (1/2 lb) Food Grade Mineral Oil
 
Ingredients are combined and mixed at a medium-high speed.  The resulting
mix has the consistency of an extra-light cake frosting.  Notes/observations
are as follows:
 
1.      The mix with 100% granulated sugar wasn't too stable.  That is, the
MO tended to separate out fairly quickly.  The powdered sugar substitution
improved the stability.  Another solution might be to run the granulated
sugar through a high-speed blender to pulverize it somewhat, thus increasing
the sugar surface area to be coated by the MO and shortening.  Yet another
solution might be to simply add more sugar to the mix.  That would likely
speed up the rate at which the bees would work the mix.  I don't know the
optimum consumption rate for effective treatment so I can't offer a
recommendation here.  My gut feeling is that I wouldn't add more sugar.  Dr.
Rodriguez indicated that a small amount of MO goes a long way so quick
consumption probably is not necessary.
2.      3 lb of this mix fits nicely in a gallon food storage bag.  To apply
the mix, I close the top of the bag with a twist tie and I cut off one of
the corners of the bag.  I then squeeze the bag, thus extruding the mix
through the small hole in the corner of the bag and applying the mix to the
top bars in the brood chamber of the hive.
3.      A food storage bag works nicely for a small number of hives.  A
pressurized canister with a hose attachment would be handy for treatment of
a larger number of hives.
4.      Top bars that have never been exposed to this treatment will absorb
a fair amount of MO out of the mix.  This leaves behind a somewhat "dry" mix
that presumably is less effective as a treatment for varroa mites.
Subsequent applications will leave a greater amount of MO available for mite
treatment.
5.      I expect that treatment with MO, whether by this method or any
other, needs to be fairly continuous year round.  The possible exception
might be during winter months where there is a break in brood rearing.  If
mites are reduced to an acceptable level at the point where brood rearing
stops, it may not be cost effective to treat again till near the time when
the queen begins laying again.
 
Comments, direct or to the list, are welcome.
 
Mike Swintosky
Dellroy, Ohio