HI Allen, You are absolutely correct, and I've gone over this in my articles in ABJ. It is time consuming to subsample larger samples. And yes, I have gone through samples bee by bee. Yes, one badly infected bee can very much skew the sample. At a 4-5M infection level at the entrance, for N ceranae, maybe 5% of the entrance bees will show an infection, and maybe 2% of the house bees. For bees at the entrance, I'd recommend taking at least 50 bees; from inside, at least 100. These samples will give you an average idea of the overall infection rate, and correlates fairly well with the percentage of bees infected, as Juanse mentioned. For larger apiaries, I'd do an entire apiary sample from the entrances, then follow the protocol on my website for processing large samples. This will give you the most meaningful infection number, since you will likely be treating by yard, not by individual colony. Randy Oliver *********************************************** 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 Access BEE-L directly at: http://community.lsoft.com/scripts/wa-LSOFTDONATIONS.exe?A0=BEE-L