I can't make a judgement on the time scale for co-evolution. I would bet that when I put preventive treatment and mixing mites and bees continuously in a theoretical model, the time to a tolerant bee/mite couple would be prolonged. We got Varroa here in the early 80ties...I like to imagine what could have happened when we had done 30 years ( alot of mite generations) of IPM and selection in stead of just treating everything and select for yield and non-aggression mainly. Lennard > 1. varroa does not reproduce in the worker brood of cerana therefore > limiting reproduction to only times when the colony is producing drone > brood. 2. swarming. Cerana swarms more than any race of bee I have been told which > limits varroa. 3.cerana keeps an opening in drone cells from which to extract varroa from > cells. > > Mellifera is not known for any of the above and not likely to change any > time soon . > > A bee which can handle varroa (untreated) as managed in commercial > operations today seems unlikely but we must remain optimistic. > > bob *********************************************** The BEE-L mailing list is powered by L-Soft's renowned LISTSERV(R) list management software. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html Guidelines for posting to BEE-L can be found at: http://honeybeeworld.com/bee-l/guidelines.htm