Guys

I believe that either the pin-killing or freeze-killing tests will identify 'normally' hygienic stocks. This is a good thing for things like foulbrood and chalkbrood resistance, but only a bit useful for Varroa. 'Varroa Sensitive Hygiene' brings the ability to identify and uncap Varroa-infested cells specifically, so these crude assessments of hygienic behaviour aren't quite good enough for the real thing.

What I intended to do last year was to raise Varroa-infested brood in a heavily infested colony, then transfer freshly-sealed combs to colonies under test. Counts of empty cells before and after a period would give an indication of how good they were at finding infested cells, but the final thing would be to sample some of the remaining cells prior to them hatching so that a true figure could be obtained of '% infested cells uncapped'.

Rodger Dewhurst and James Kilty were talking about more casual opening of patches of sealed brood to look for numbers of sterile vs fertile mites remaining, I think.

Foulbrood happenings took my spare time away, and made it wise to treat my bees for Varroa, so it didn't happen. I did supply a post-graduate in Edinburgh with lots of Varroa-infested comb for her studies. One interesting thing was that after quite a long period of queenlessness the next round of sealed brood had most of the mites inside but the mites were dead! No treatment applied at that time. I guess that they got old.