John Burgess a écrit:

> As I recall, this device is a hive floor constructed of closely spaced metal
> tubes, which allow the mites to fall through.
> My question is: does this have any advantages over the mesh varroa floor
> used without a bottom board, as discussed in posts earlier this year?
>
> John Burgess, Editor Gwenynwyr Cymru/The Welsh Beekeeper

This hive floor is constructed of plastic tubes and not of metal tubes for a
few reasons :
Plastic is cheap. Such a manufactured bottom-board would not be more expensive
than an ordinary bottom board.
It may be transparent, allowing light to enter the hive, which makes bees
milder.
It is not heat-conducting. Even when it is freezing, bees can walk on the tubes
without getting cold.
The comparison that I can do between the tubes board and the mesh board is the
following :
The holes are much bigger in the tubes board : 3.5 X 450 mm instead of 2.2 X
2.2 mm. A much higher proportion of varroa mites should therefore fall through
the board. Much bigger scraps are also eliminated. I can find cells caps under
my hives. And the smaller the holes are, the easier they are filled in.
Ventilation is mild and evenly distributed in the tubes board. The total
aperture is six times less than in the mesh board. A second slatted bottom
board to be used in winter is therefore unnecessary, at least in place where
winters are not too cold. Here in Paris, temperature may drop to -5 °C during a
week or two. I have not yet experimented lower temperatures.
Stainless steel mesh is very expensive.
A first experiment has been carried out in France on one hive with a mesh board
(See : L’Abeille de France, July-August 1998). The author reported that
withered wings bees appeared during the first year without treatment and
disappeared later. That is about what I observed myself. One of my hives has
not receive any treatment for three years, the others for two years.
Best regards.
Jean-Pierre LE PABIC
RUEIL-MALMAISON (10 km from Paris)
FRANCE