Since I was a bit in a time stress I fergot to explain in my last message
that when checking colonies for presence of mites using fumigants dead
mites can be collected a half day later (in the morning) on a sheat
inserted under the cluster through the hive bottom entrance. From the view
point of manipulation the larger space between the bottom and the frame
bars is an advantage.
Thanking for appology,
Vladimir Ptacek