> On Fri, 11 Oct 1996, Dave Jurgens wrote:
 
 
> If menthol is not effective below 20 C, i'd imagine that neither
> would any other essential oil that needs  to volitilize (unless of
> course it some how moved around with the core of the cluster). The
> European scientists who have evaluated the Italian thymol-based
> varroacide APILIFE VAR, found the product's effacacy really tailed
> off in cooler weather.
 
I used Apilife Var this Spring,  to try to reduce the number of mites
that would build up during the season.  The following numbers are
daily mite knockdown figures for 50 days from one colony that received a single
(ie. half treatment) in April.  This Spring was judged cool by local
folk, the frost nearly ruined my early potatoes!  I suppose the daily
min/max temperatures would have been something like 2-13C.
 
31, 24, 37, 7, 12, 14, 25, 11, 26, 42, 22, 18, 7, 7, 13, 6, 10, 11,
13, 7, 14, 10, 4, 4, 3, 5, 2, 5, 1, 7, 10, 4, 3, 1, 2, 1, 3, 1, 3, 0,
4, 3, 3, 0, 0, 0, 0, 0, 0, 0.
 
The reason that the colony had so many mites this early in the year is that it was very
heavily infested last year,  in fact I counted/estimated a drop of
more than 13,000 mites last Autumn (or 'Fall' as some of us would
call it).  I am suprised that the colony survived.
 
I leave you to draw your own conclusions,  but my guess is that the
treatment is effective at lowish temperatures,  but takes longer to
take effect.
 
In my experience ApiLife Var - even in a warm British Summer (is
there such a thing?) - takes much longer to produce results than
Apistan or Bayvarol, which give something like 80% knockdown in a
couple of days  but does this matter?
 
In passing,  I have no arguments with the use of Apistan but the Sandoz/Zoecon respondent,
was perhaps wrong in suggesting that S/Z are unique in researching/paying for
licensing Varroacides.  Apistan is not licensed in the UK at the
moment,  but we have a similar product from Bayer.  Also,  recently a
new treatment was announced by a French company, called Apivar (NOT to
be confused with ApiLife Var),  based on Amitraz.
 
Best wishes
 
Joe Hemmens