Robin said:
We must not forget that varooa mites are in every single hive once they have
arrived in an area, and every hive dies out with say 5 years at most if not
treated effectively.

Many hives have been left untreated to see how long it takes for varroa to
kill the hive.

 Two years is the usual time frame when left untreated *unless* you are
dealing with a hive which is very hygienic or has  exceptional survivor
traits (SMR etc.).

Quite a bit of discussion about the subject is in the archives and will
support the two year *general* statement

Robin said:
  Varooa is only controlled so effectively because of Apistan

Apistan has been history in most parts of the U.S. for quite a few years.
Returning to Apistan after three or four years has met with failure also.

Robin said:
- scientists have not had as much success with thymol as Peter or we would
all know of it. Even Vita [who make both Apistan and Apiguard which contains
thymol] do not advocate using only Apiguard.

U.S. tests on Thymol have never produced effiacy in the range claimed by
vita Europe. I wish I could report better news. thymol does provide a
certain amount of control but needs to be used in warm weather such as
August in the Midwest.

The problem with a control in the 50 to 60% range (thymol testing reported
U.S.) is the carry over load of varroa from treatement period to treatment
period.
.
 Even formic acid liquid has trouble knocking back a high infestation of
varroa and in my opinion thymol would also.

I might point out for those new to the  discussion
that there is a point called *threshold* (or varroa mite load) when reached
that the hive CAN NOT BE SAVED REGARDLESS OF TREATMENT METHOD.
The point I tried to make above is when you are below threshold but not by a
huge amount and you try to clear the hive with a 50-60% control you are
spinning your wheels.

I predict when resistance to Apistan happens you will soon find fault with
thymol. The still effective Apistan treatment (U.K.) is making the thymol
treatment seem more effective in my opinion.

Bob

Ps. In the U.S were are in the same varroa book but in later chapters.

::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
-- Visit www.honeybeeworld.com/BEE-L for rules, FAQ and  other info ---
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::