Daniel Thommen wrote:

> 2 Years ago a lot of beekeepers had a bad surprise. We actually lost about
> 30% of our hives and think that this was due to the inefficiency of apistan
> against Varroa.
> So I wonder if other beekeepers made the same experience.

I have treated fall and spring with Apistan for years now, but a few days ago
noticed a lot of worker bees crawling on the ground in the vicinity of one of
my hives.  On inspection, every one of them had deformed wings, so I knew
varroa got to them.  It has been only about six weeks since I removed the
Apistan strips, therefore obviously I have begun to experience varroa
resistance to Apistan.  I made a quick call to get some Check-Mite (coumaphos)
strips, pulled the supers (4 of them, two thirds filled), and inserted these
dangerous looking things into the hive.  While in the colony I pulled drone
pupae and checked for mites - about three/fourths of the pupae had mites.

I then looked at other colonies in the same yard, pulled drones, but they all
were still clean.  It looks like resistance is developing, but yet spotty.

Ted Fischer
Dexter, Michigan USA