I found this video which shows bees removing larvae (or should I write pupae?) infected with varroa. The page belongs to a Germany-wide association of beekeepers which work together to breed varroa-tolerant bees. They have very strict selection criteria and isolated mating sites, and they swap queens of successful colonies amongst each other.
http://www.toleranzzucht.de/home/video/
I found it very cunning how the mite still got away!
It also shows the needle-test which is described on this page (in English):
http://www.beekeeping.com/articles/u...port/index.htm
Doris
Bookmarks