The Blue Shop Towel Method
for Tracheal Mite Control in Honey Bees

 
  Click to enlarge Click to enlarge Click to enlarge 1/3 towel placed at back of hive to avoid driving bees off brood.  The pink item is an extender patty.  
  Dipping 1/3 roll of towel (core removed) into a 50/50 mix of Crisco and menthol.  Keep the mixture just above the melting point. Removing the saturated roll of towel.  The roll is hot and it drips.  There are strong fumes.  Be careful.  Work outdoors if possible. Bagging a finished roll of towels. Menthol evaporates if not enclosed.  Use ASAP, and store towels in a cool place until needed 1/3 towel placed at back of hive to avoid driving bees away from the brood. The pink is an extender patty. Feeder in foreground  

Makes 60 rolls of 55 sheets each. 
Treats 3,300 hives once or 1,650 hives twice

  1. Melt roughly equal amounts (by weight) of Crisco vegetable shortening and menthol crystals in a pot.  Do it outside or under a fume hood.  Be aware: the mixture is very flammable.  Avoid excess heat, since menthol is very volatile -- and too expensive to boil off for no good reason.
               *  1 box Crisco is 20 kg.  That is 20,000 g (or 44 lbs)
               *  1 drum of menthol is 25 kg.  That is 25,000 g (or 55 lbs)
               *  1 ice cream pail of menthol is about 4 lbs.
               *  Melt 1/2 box of Crisco and 5-1/2 pails menthol at a time, using a washtub and torch or burner.

  1. Cut 20 rolls of blue shop towels into thirds to make 60 rolls about the size of toilet paper rolls .

  2. Remove the cardboard inner core.  Soak the rolls of  towel in the menthol/oil mixture until fully saturated.

  3. Drain a bit and place the rolls into ZipLoc bags.  Store them in a cool place until needed.
                *   Result: 60 (1/3 size) rolls x 2 batches
                *   60 x 55 sheets per roll = 3,300 sheets each with 6g menthol and 6g Crisco           

  4. Take them to the field and place one of the 1/3 sheets on the top bars of each hive at the front or back, not right over the cluster.  Daytime temperatures should not exceed 70 degrees F or be much under 50.  Results will vary with the hive and entrance design, location and whether the bees are still wrapped or not.  Menthol will evaporate if left in the sun or a hot place.  Keep unused rolls sealed and in a cool place.  Warning: Too much menthol will drive bees off the brood or kill brood.

  5. Repeat in ten days or two weeks

  6. That's it.  Forget about tracheal mites for a year or more. (Do check a bit in the fall, though)

We only got around to one treatment and found a year later that we did not find tracheal mites
 in a cursory exam that should have turned up any serious problems.

We treat in spring before the weather gets too hot.

It's best to check your bees twice a year, though -- spring and fall.
Don't just assume you have control. Be sure.

Note: Samples taken after treatment will test positive, since dead mites remain inside
 the adult bees until the bees die of old age.  Therefore subsequent testing to prove 
efficacy must wait at least six weeks after the treatment.

Here are four good articles from BEE-L with more details about the Blue Shop Towel Method