Lesson learned

Before I share what I have recently and painfully learned, a quick update on the rest of bee activity.  

A couple of days ago, I pulled out the trays (from below the bottom screen) to clean them.  As always, there were a number of dead bees on top of them, albeit more than usual.  I also noted that there were a fair number of drones, definitely not as usual.  If you can enlarge the picture, you will see that 42% of the bees are drones.  The bees evict the drones in winter, but I wonder if they started early this year and that these fellows were trying to get back in.

I started bringing in the fall harvest of honey.  Since I only have one escape board, I can only get one super each day.  I extracted the honey from two supers (one from each hive) today and put one sticky back on, with the bee escape board.  Tomorrow, I'll take off the super and put the escape board and remaining sticky onto the other hive and the day after that, I'll be able to extract the rest of the honey.
I did take a look into both hives but looked no further than just finding capped brood.
For the past several months I have been saving the propolis that I scraped off the frames.  I now have a  small jarful.
Now for the hard-learned lesson: pay attention to the experts.
Most sources recommend storing comb in special ways, but I erroneously figured that if they were getting air and some light, that would be enough.  Today, I looked in one of the nucs in which I was storing some comb, and this is what I saw:

 

Close up of the webbing and frass

The (out of focus) culprit

These two frames are ruined and I will scrape them clean.  In the meantime, two frames with only a few cells with webbing are currently in the freezer.  It looks like I need to purchase some Paradiclorobenzene (PDB), 80% acetic acid or a large freezer.