In southeastern Pennsylvania, USA, many people are treating twice a year for
Varroa.  One treatment before the spring nectar flow (which begins in
mid-April) and a second treatment in late summer.
      Our main nectar flow is from tulip trees (Liriodendron tulipfera) in
the month of May.   Autumn Apistan treatments have made it necessary for us
to extract earlier, mid-summer for me.
Tim Sterrett
Westtown, Pennsylvania
 (Southeastern) USA
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39 55 51 N 75 33 08 W