But if high mite loads triggered hygienic behavior, wouldn’t it be triggered without a brood break? If old mites can’t reproduce successfully, how do they begin reproducing in the spring after a long winter brood break? At some point all bees are hygienic, the question is where is the trigger? For some dead larve are removed immediately, others it takes a couple of days I am thinking that its probably triggered faster when the brood nest is tiny vs when its 5 frames... but just speculation... As for age of mites, don't know, just a thought maybe winter mites and summer mites are also different ?? Just pointing out after doing it there seems to be more to the picture than what we see. Charles *********************************************** 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