On page 14 of the Varroa Mite Handbook it states on adult bees the mite must
squeeze between the OVERLAPPING segments in order to reach,and finnally  cut
through, the thin membrane and draw its fill.
Question: If the bee were smaller and the bees were in a winter cluster with
no brood and had allready disposed of the drones for winter wouldn't smaller
bees be a method of control?