I was following a thread and thought that the below might add some
information for those that posted info or had questions about menthol and
oil.


Menthol-Canola Mix for Treating Tracheal Mites: Results of Research
Conducted from Fall 1996 to April 1997
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Jim Amrine, Terry Stasny, & Robert Skidmore
West Virginia University
Division of Plant and Soil Sciences,
P. O. Box 6108, West Virginia University
Morgantown, WV 26505-6108 USA
Telephone: 304-293-6023
Fax: 304-293-2960
E-mail: [log in to unmask]



1): Measure and mix components:

Place two standard packs of menthol crystals (3.4 ozs. or 100 grams) in an
8 oz. (118.3 cc) measuring cup, then add canola oil to fill. Microwave for
4 mins. 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 are 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.

Don Jackson's Shop Towel technique: A very similar technique was published
in the February issue of the American Bee Journal by Don Jackson (Jackson,
Don. 1997. Tracheal mites, menthol, and shop towels. Amer. Bee J. 137
(2):138-139). He used a 50-50 mix of canola and menthol, heated on a stove,
and then cut rolls of shop towels in half and dipped them into the pan to
saturate with the mix.



Additional Research:

We intend to find the optimum amount of menthol needed to obtain control--
maybe of this amount could be used--maybe more should be used. We also
intend to observe the effects of this mix on varroa mites.

4): Calculation of costs (29 April 1997):

One cup of mix contains 100 grams of menthol = 100/453.6 = 0.22 lbs or 3.4
ozs.

One lb of menthol costs:
Lorann Oils: $36.30 per lb. (bucket of crystals)
Dadant: $24.82 per lb. (12, 50 gram packs for $31.50)
W. T. Kelley: $23.68 per lb. (10, 50 gram packs for $25.00)
Mann Lake: $19.85 per lb.

Menthol for one cup of treatment costs:
Lorann 0.22 * 36.30 = $7.99
Dadant 0.22 * 24.82 = $5.46
W. T. Kelley 0.22 * 23.68 = $5.21
Mann Lake 0.22 * 19.85 =$4.37

1 cup or 8 ozs of canola cost (47 oz bottle) 8/47 * $2.20 = $0.37

Total cost for materials (not counting labor):
Lorann: 7.99 + .37 = $8.36 for 15 colonies = $0.56 per colony
Dadant: 5.46 + .37 = $5.83 for 15 colonies = $0.39 per colony
Kelley: 5.21 + .37 = $5.58 for 15 colonies or $0.372 per colony,
Mann Lake: 4.37 = .37 = $4.74 for 15 colonies = $0.32 per colony

Costs using 50 gram packets for standard menthol fumigation:
Lorann Oils: $36.30 per lb. (36.30 / (453.6/50)) = $4.10 per colony
(you provide the perforated packets at $.10 each)
Dadant: $24.82 per lb. (12, 50 gram packs for $31.50) = $2.62 per colony
W. T. Kelley: $23.68 per lb. (10, 50 gram packs for $25.00) = $2.50 per
colony
Mann Lake: $19.85 per lb. / (453.6/50) = $2.29 per colony
(you provide the perforated packets at $.10 each)

5): Storage experiment:

We conducted an experiment for two year storage of menthol packets (from
Man Lake) sealed in a heavy plastic bag and kept in a refrigerator at 35
degrees F.

After storage:

 Packet  Weight of Packet (grams)*
 1  53.71
 2  51.00
 3  52.23
 4  53.18
 5  51.88
   Average Value = 52.40 g (se = 1.07)
   Avg. Bucket Wt.= 2.34 g
   Avg. g menthol / packet = 50.05

Conclusion: very little menthol was lost.