Some suggest that one important trait for varroa resistance is smaller brood nest and less brood rearing. That may be so for some stock resulting in lower growth rate of varroa mites. It’s also resulting in a smaller honey crop for the beekeeper.
One of my goals in breeding varroa resistant stock is to keep a big brood nest and high brood production, for quick spring development and a big bee population when the main nectar flows is at hand. That means a maintained good honey crop for the beekeeper. But also a long brood break when nectar and pollen availability is low. That is positive for the fitness of the bees. Vi can see now in our local bee club when our bees here are very varroa resistant that our bees continue to give us a good crop and have the good traits we are used too. A big brood nest is present during brood season. It doesn’t matter if the big brood nest gives varroa mites good opportunities to reproduce. Our bees are good at chasing, catching and biting mites, as well as discovering and disturbing mites in brood. Even reinvasion of mites in a moderate degree doesn’t hurt the bee colonies enough to set them back through too much virus growth. What we have shown in our local bee club is that it is well possible to develop varroaresistant bees with ”normal” breeding traits, for the benefit of both bees and beekeeper.