>The mite density numbers reported from "resistant" colonies presumably produced by natural selection are not impressive. 

Most of the contemporary data that I am aware of that has been collected on this score has been by Dr. Martin.

In the present 'Parallel evolution of Varroa resistance in honey bees: a common mechanism across continents?' article under consideration it is noted:

'In the Africanized colonies, which are all resistant, average worker-brood infestation rates have fallen from 20% during 1996–1998 to 4% in 2018–2019 (figure 1h). Additional preliminary data from UK-resistant colonies (n = 44) collected by the authors and found that brood infestation averaged at 6% and was not significantly different to Africanized colonies in 2018/2019 (U = 460, p = 0.052).'

'Interestingly, we found that worker-brood infestation has fallen significantly (U = 123, p < 0.0001) from 20% to just 4% over the past two decades in resistant colonies in South America (figure 1h) currently the only location with long-term data.'





             ***********************************************
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