I missed the last club meeting this May but I did hear from some of the members the following:
Question #1: “How long should we keep the oxalic acid-treated towels in the hive.”
Answer #1: From my notes of the talk I gave November 2017 at the club and from the information I presented at the March field day, the answer is: “Within three to four weeks after placement, the bees should have removed most of the towels. After four weeks, any remaining towels can be removed.
Question #2: “Where should we place the towels?”
Answer #2: One towel per nuc/brood box. If there are two brood boxes, then place one towel on top of each brood box.
Questions #3 and #4 that should have been asked are, have you sampled for mites prior to and following treatment? If you haven’t then you really can’t know what the consequences of your treatments are accomplishing!
I’d ask the readers to reference Randy Oliver’s website, www.scientificbeekeeping.com for additional information.