Malcolm Roe asked why both chemicals were not available in most
   countries.
 
   I understand that these chemicals are so closely related that should
   a pest develop resistance to one, it would most likely be resistant to
   the other. This has been given as one of the reasons flumethrin has not
   been introduced to the North American market (not enough years of
   effectiveness left to recover investment??). This would imply that the 2
   products are not suitable for an "alternation of control" strategy to
   avoid resistance.
 
   There appears to be a great difference in concentration of active
   ingredient in the products available, however.
   Bayvarol has a much smaller concentration of flumethrin (a few (3?)
   milligrams per strip, anyone have a label handy?) than Apistan hive
   strips, which are labelled as 10 % fluvalinate. (1 strip is 6 grams. 10
   % fluvalinate = 600 mg/strip). Unless a different method of expressing
   concentration has been used, it looks like flumethrin is active at less
   than 1/100 of the concentration of fluvalinate. Any speculations on the
   implications of this difference?
 
   By the way, Malcolm, are 4 Bayvarol strips the recommended treatment for
   1 hive? (a normal-sized colony, in ____ (fall?)).
   Is fall treatment recommended? is spring treatment an alternative?
 
   Are treatments in both spring and fall sometimes necessary (when
   re-infestation from un-managed colonies is high).
 
   Is there concern or a tendency for people to re-use the Bayvarol strips?
 
 
   Kerry Clark, Apiculture Specialist
   B.C. Ministry of Agriculture
   1201 103 Ave
   Dawson Creek B.C.
        V1G 4J2  CANADA          Tel (604) 784-2225     fax (604) 784-2299
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