Just want to talk about my very limited experience with IPM bottom boards and ask for some input on your experiences. I had only one hive, which was wintering for the second year. In October I went to Brushy Mountain to get a couple of hives and other things and I decided to go with IPM bb's on the new hives and get one for the existing. I painted it and put it on in November, and monitored mite fall to see that Apistan was doing it's job. When I removed the strips in late December I also removed the corrugated plastic monitoring board as everyone says to do. In mid December I opened the hive for inspection on a warm sunny day to find the cluster had abandoned the bottom hive body and moved up, leaving several frames full of honey behind. It has been very cold lately, Saturday morning was below zero, so I decided to tap on the hive this evening to make sure all was well. No reaction. So I popped the cover and found the cluster frozen to death still in place on a frame with honey. Am I just gullible for listening about leaving the bottom wide open in winter. It gets colder in the mountains of WNC than surrounding areas, but I have read of people using the IPM bb's open pretty far up north. Any input would be appreciated.
I left mine on, and I'm in PA. I do have the hive stands built, to prevent updrafts though. It has been cold this winter. We had a lull in the cold about 2 weeks ago, and I still had bees. Time, that 4 letter dirty word will tell though.