> > >Just as good a case could be made against short term antibiotic use: if > you use it for a > week or two in spring, you will kill off the susceptible bacteria, leaving > only the resistant > ones. Pete, 'm not sure that a good case could actually be made. Short-term use in a portion of an operation utilizes the "refuge strategy" of pest resistance management. The strategy being that the remaining nonresistant pest will generally be more fit than the resistant pest (in the absence of the chemical control agent), and outcompete it once the agent is removed. With continual use of antibiotic, there is no refuge for nonresistant strains of bacteria. Therefore, selective pressure would strongly favor any resistant strains that possess alleles for resistance, or randomly mutate, or pick up plasmids for resistance, or epigenetically upregulate genes that confer resistance. >I have met many people who have successfully stamped out AFB. I have personally done so a few times over the years (serious spread in the operation) mostly by burning, plus judicious use of antibiotic in targeted yards, and when doing "shake and bake." I haven't used antibiotics prophylactically for a number of years, which is why I'm curious about Bob's experience with EFB when OTC isn't used. I'm seeing more EFB-like symptoms, but they don't go away like EFB used to when a good pollen/nectar flow comes on. I've been too busy to do a good controlled trial of OTC and tylosin against the symptoms, but will try to get around to it. So far, either antibiotic (dusted) appears to help. 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