Larry Krengel writes:
  What are the thoughts about using menthol?  or how about grease patties?  I
have never heard it suggested and assume there is likely a reason.  No
tracheal mites in package?
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  While Varroa mites kill colonies in late summer or in autumn, tracheal
mites are a winter problem.  Tracheal mites debilitate or kill colonies in
late winter. Menthol is used at the end of summer (while the weather is still
warm) to reduce tracheal mite populations going into winter.
   Apistan is used early in spring (before the honey flow begins) and again
in mid-summer (as soon as the honey crop is off) to reduce the build-up of
Varroa mites during the honeybee brood-rearing season.
     Grease patties can be used all year, but they probably are most helpful
to the bees during winter.
       Incidentally, unless menthol is used properly, it is useless.  Menthol
has to be applied when the temperature in the colony is high enough to
vaporize enough of it to kill mites, but not so high that the vapor drives
all of the bees out of the colony.  Grease patties (or some other delivery
method for oil/grease) is probably the main treatment for tracheal mites.
Tim
Tim Sterrett
Westtown, (Southeastern) Pennsylvania, USA
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