(( Leading a Varroa Management workshop this weekend, so tying up loose ends that have been bothering me)). The return interval for OAV treatment is the subject to idiosyncratic recommendations. Can someone cite a published source for comparative efficiency and safety of different return intervals. I have seen periods of 4-7 days recommended. Typically the recommendation appears based on inductive reasoning about open brood (and/or uncited factoid about the average phoretic period of mite mothers). Any trials actually done of behavior of colonies under different return intervals ? *********************************************** 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