Hello All
 
I was wondering about the possible rate of spread of Apistan/Bayvarol
resistant mites in the light of a recent post reporting these mites in South
Dakota USA.
 
Would I be correct in saying that the spread of the resistant variety will
be considerably faster than that of the original mites?. I say this for the
reasons shown below, and would be grateful - as always - if I can be put
right if I am in error. (I am only two years at beekeeping).
 
The original mites spread by physically moving into a new area. I am taking
England as an example, since it is the only country, apart from my own, with
whose beekeeping practices and recent beekeeping history I am somewhat
familiar. It has taken just over 6 years for the mite to achieve a presence
in most parts of England starting in the South West in April 1992. (Some
would argue, that but for migratory beekeeping, the colonisation time would
have been far longer, but that is not an issue here).
 
I believe, however, that the resistant mite is in a far better position for
spreading its presence. I am assuming that resistance is achieved by the
mites' exposure over time, to control chemicals. If this be the case, then
resistant mites will eventually appear in thousands of hives dotted
throughout the area colonised by the mite. Thus the spread of the resistant
mites will be very rapid indeed.
 
If the above is true, England will be colonised by resistant mites in far
less than 6 years from the date of the first confirmed outbreak. (In this
scenario, migratory beekeeping will not be a major factor, if indeed it be a
factor at all).
 
And of course this will occur in all countries where the varroa mite is
found, (this is now rapidly translating into 'all countries').
 
I suppose that the advent of a chemical which operates differently to
Apistan and Bayvarol, and to which initially at any rate, the mites will not
have resistance, will in the short term improve matters.
 
But what of the long term?.
 
What do the list members think?.
 
 
Sincerely
 
Tom Barrett
49 South Park
Foxrock
Dublin 18
Ireland
 
e mail [log in to unmask]
Tel + 353 1 289 5269
Fax + 353 1 289 9940
 
Latitude  53 Degrees 16' North
Longitude  6 Degrees  9' West of Greenwich