Re: Sundance Pollen trap Problem
I'm sorry you are having difficulties. As you said, one trap worked very well last year and even that trap is not working this year. I suspect that there is a problem that is not trap-related.
You think that the bees may have died from the cold...I really doubt that. A friend of mine decided to deal with a hot hive by taking the outer and inner covers off one winter; figuring the cold and wet would kill the hive. We always have several nights below zero, and average 30-50 inches of snow. In the spring, he found that the hive survived just fine and was as mean as ever! In a similar vein, on many occasions I have had hives tipped over by kids on snowmobiles, by bears, and just by accident. Even when the hive bodies get separated, the one with the queen usually survives. So, it is unlikely (I think) that cold killed your bees.
Just for the record, the bottom-mount Sundance trap lets the bees enter along both sides, across the back (as you said) and across the front! These entrances are not terribly obvious, but they are there and readily used by the bees. Moreover, the bees move into the brood nest by going through wire that extends almost all the way across the width and depth of the hive. That feature is very important as it assures that the pollen is well distributed across the pollen drawer and is not deposted in one or even a few clumbs that are likely to compact and mold.
With the symptoms you describe, I'd look for insecticide damage.
Best of luck,
Lloyd Spear, Owner of Ross Rounds, Inc. Manufacturers of round section comb equipment and Sundance Pollen Traps.