Adrian Wenner a écrit:

> In Santa Barbara proper, we now have good survival of feral colonies ---
> obviously without treatment.  I consider that survival to be a POPULATION
> phenomenon, in that queens mate with drones from colonies that have also
> had no treatment.  I treated this possibility more fully in this network on
> 21 April.
>
>                                                         Adrian

On my opinion, survival of honey bees colonies in varroa infested area may be
due to at least two reasons :
1 - bees are resistant
2 - they live in conditions that allow them to survive to varroa mites
In Europe, numerous examples of feral colonies living without treatment in
highly infested areas have been reported. However, not a single example of
resistant domesticated colony has been reported. Moreover, the existence of
feral and domesticated colonies in the same area results in crossing so-called
resistant and non resistant colonies which may destroy resistance.
The assumption made in Europe is that many varroa mites fall from the feral
colony and are eliminated in this way, having no means to climb back. On the
contrary, in a hive, they do not have any difficulty joining up with their
initial environment from the bottom boards.
That is why I have experimented for some years a specially designed bottom
board so that varroa mites fall under the hive. It is made with tubes, one
under each frame, 3,5 mm apart (have a look on :
http://www.apiservices.com/plateau-anti-varroas/, French, English and German
version).
I count from time to time varroa mites which fall under four hives during one
week time. The first two hives have not received any treatment for three year,
the two other for two years.
The last counting periods were : 12 to 20/12/98 (8 days); 17 to 24/1/99 (7
days); 4 to 11/4/99, (7 days); 11 to 18/4/99 (7 days); 18 to 25/4/99 (7 days) :

And the results were the following :
Hive n° 6 : 94, 126, 14, 16, 20.
Hive n° 2 : 90, 38, 31, 31, 7.
Hive n° 5 : 280, 112, 4, 5, 4.
Hive n° 3 : 61, 57, 0, 2, 0.
These are by far the best results I have obtained. This experiment should
however be carried with different bees, in different places and so on to be
validated. Until now, I am the only one !
Jean-Pierre LE PABIC
Rueil-Malmaison (10 km from Paris), FRANCE