In message <B1739ZWRLI50WD*/R=GALAXY/R=A1/U=KCLARK/@MHS>, "Kerry Clark of AGF 784-2225 fax (604) 784 2299" <[log in to unmask]> writes >The key difference seems to be that 50 to 60 % > of these varroa in worker brood are infertile. If I remember rightly this infertility is one of the features that allows A.cerana and the mite to co-exist. > > By the way, although many of these discussions use "tolerance" and > "resistance" (to varroa) interchangeabley, it seems to me that > tolerance implies no effect on the (former) harmful agent, while > resistance would include (but maybe not be limited to) mechanisms > that inhibit the source of the harm. > Is this distinction consistent with usage of these terms in > parasitology? > > If so, it seems to me we should be referring to varroa being > selected showing "tolerance" to fluvalinate, rather than > "resistance" Yes, resistance and tolerance are being used very loosly. Correct me if I wrong but resistance is an attribute of a population while tolerance is an attribute of an individual. Tolerant mites may or may not breed to produce a resistant population. -- Dave Black <http://www.guildford.ac.uk/beehive>, Guildford, GU1 4RN. UK.