"W. Allen Dick" wrote:

> And, if the USDA did develop the treatment, is it written up somewhere?

Jim Amrine,  at West Virginia University.
This is his writeup, in part. The last I saw, he was testing the amounts
and also the effect on Varroa.
Bill Truesdell
Bath, ME

1): Measure and mix the following:
Place two standard packs of menthol crystals (3.4 oz. or 100 grams) in
an 8-oz. (118.3 cc) measuring cup, and then add canola oil to fill.
Microwave for 4 minutes at 50% power. Check to see that all crystals
dissolved—if not, microwave for an additional minute at 50% power. Must
be used while warm otherwise crystals will reform.
2): Add to paper towels:
Remove 30 paper towels from one roll; fold in half and stack. Put stack
of paper towels into a large zip-lock bag and add 1 cup of warm
menthol-canola.
Zip the bag shut then squeeze the towels in the bag until all towels are
evenly saturated. If one end of towels is somewhat dry, turn the bag
sideways putting dry end down—in about 10 minutes, all will be evenly
saturated.
Thus, one cup of menthol-canola mix will treat 30 paper towels—using 2
towels per colony, this will treat 15 colonies.
Towels can be stored at room temperature indefinitely if the bag is
zipped closed.
3): Add to colonies:
Do not add to colonies while a honey flow is on. Place one paper towel
over the top bars of each brood chamber. Best time to treat is
September.  (Tracheal mites are usually not a problem from May to
September, so no menthol needs to be used until the time that mites
begin to build up in late August or September). Colonies can be treated
anytime during the winter when temperatures rise above about 45 F. We
recommend this treatment whenever tracheal mites are found; additional
treatments can be made in December, January and February. The bees will
chew up the paper towels and discard them at the entrance in 3-4 days
(or longer in winter). This mix caused no harm to our bees but
definitely reduced or eliminated the tracheal mites.