Dear Chris,

If you consider using organic acids (formic and oxalyc acid) to fight
against varroa "organic beekeeping", the information on our URL might
interrest you.
Over here many beekeepers treat their hives with formic acid since about 10
years with great succes. Lately we also used oxalic acid that is even more
efficient if applied during no brood periods.

Jan's URL given in his last mail desribes a method that also shows good
results over here (up to 80% efficiency). We use the method less methodicaly
and just cut capped dornes out of the hive. But this treatment alone in
unsufficient if done without other measures.

Jean-Pierre talked about anti-varroa bottom board in his last mail . We also
use it but only to follow the varroa infestation to avoid unnecessary
treatment if the varroa chute rate is low enough.

Our varroa board is removable and a mesh avoing bee entrance from the bottom
is inserted between the colony and the board. Of course, the falling varroas
fall rigth through the mesh on to the ground and decreases infestation. But
I can assure you that I still need to treat my hives against varroa mites to
keep the population under a reasonnable limit. If you are interrested in
these treatments, have a look on the articles referenced under
http://www.club-association.ch/apigeneve/varroa.html . I'm sorry they are in
french ! If you do not know french and do not want to learn it quickly
please ask the author or co-author of these articles for an english
translation, his address is :[log in to unmask]
:-)
Daniel Thommen (10 DB hives at 420 m )
Grand Pré 76
1202 Genève (Switzerland)
http://www.club-association.ch/apigeneve