I wouldn't count on Crisco patties by themselves.  I understand that they
deter the tracheal mite but although I have used these patties for years
I still acquired a significant mite problem.  I used menthol crystals on
1 yard last year and one hive in particular could always be counted upon
to provide tracheal mites for examination.  It died over winter by the way.
 
I would be interested in hearing about the use of menthol crystals from
those of you are successful with these.  I tried them one year and the
next spring my problem was worse.
 
I then switched to Formic acid and every year since, my tracheal mite
problem is less severe.
 
Yesterday I unwrapped a yard of 36 colonies and found only 24 had
survived.  Of the survivors about 8 were very weak.  I collected bees
from several of the weak colonies and dissected them - 60% were
infected.  I also caught 3 queens and dissected them - none were infected.
 
I must check my notes to see if my formic acid treatment was different in
this year because other yards have had little evidence of trach. mites
and relatively good rate of survival.
 
I do not yet have Varroa in my area (as far as I know) and do not look
forward to it.  The tracheal mite problem has been bad enough.
 
Eric Abell                           email: [log in to unmask]
Gibbons, AB, T0A 1N0
Canada
(403) 998 3143