That comb looks a little old. I am planning to do a couple of shook swarms this spring to see if that re-energizes the colonies. I have a couple in mind that didnt produce well and have old dark comb.
I saw at least one frame that was mostly drone comb. I know that varroa is new to your country, but it certainly is not to us! That frame of drone comb will become a varroa generator, producing almost TWICE the reproduction rate. Get that frame out of there! Chalk brood will be nothing compared to varroa if you enhance their reproduction rate.
