This is my first year keeping bees, just outside Denver, Colorado, USA. I was planning on one hive but caught a wild swarm in the spring so I setup two (New Nuc in a regular Langstroth and wild ones in the Flow).
The Nuc hive seemed stronger all year but today, after our first snow (10"/25cm) and three days of cold temperature (6ºF/-14ºC) I found a massive die off on the nuc hive. Piles of bees on the ground in front and covering the entire bottom board. Still some live bees in the hive, but this is a lot of death.
After I dumped everything out from the bottom board:
I haven’t counted varroa, but in my tiny knowledge this seems like a lot of sudden loss to mites?
I didn’t see anyone spraying and it’s been snowing and icy roads and cold so I doubt that was it. I did have some loss in the spring due a neighbor’s pesticides.
I have been negligent in my winter prep and will work on it this weekend. Thanks again!
Good points, so strike that concept! I know we have a La Nina year building, and as a skier, it seems that the snow is better in UT and CO in La Nina years.
P.S. I still think that a moisture quilt top and some outside wall insulation may help a lot
Just food for thought. Such death rates at first frosts quite often caused by disconnection of the cluster from food source when it tries to heat brood. Diseases and parasites make situation worse.
Your hive entrances look huge for -14ºC. I would reduce them to something more reasonable: 5-10 cm. Not sure how cover is constructed, but I would address excessive ventilation there too if exists.