Hi
I had very heavy mite loads in the middle of August, after having treated
with Apistan in April.

We used coumaphos in fall of 2000 & spring 2001. That fall mites were
acceptable, so we went back to Apistan fall 2001 & spring 2002. It hasn't
worked, so one wonders: 1) did the coumaphos not knock out resistant mites?
2) did we pick up resistant mites from other hives? 3) did environmental
conditions cause this rapid build-up?

We were hearing from other beekeepers that mites were heavy by the end of
July so we decided to examine all our hives for mites. By the way, we do keep
a dozen or so hives untreated during the season. The mite loads on these were
not higher than the treated ones, so it makes for a lot of head scratching.

pb