Perhaps it was not properly coated in wax from the beginning or other reasons.
BF, thanks, that has been my main thought. I have a 100-pack of foundation that are pre-waxed, but I recently felt that the wax was so minimal it seemed negligible. Last week I melted down some really nice wax (ver aromatic, A+ stuff) and applied my own coat to about 14 foundations for which my daughter and I assembled frames for. We subbed those into this same hive during this recent inspection to see if they'll take to it.
As for this frame in particular (pictures 1 & 2), one side has a bunch of brood and the other is filling with nectar. As I don't want them to lose any of this at this time, I think for attempt number one at encouraging them to accept the rest of the foundation, I'm going to brush off the bees from this frame, then use a small brush to apply a new coat of fresh wax to the areas they're neglecting, re-install the frame right back into the hive after coating and see if that prompt them to fill in the blanks so to speak.
If that doesn't work, then I may move this frame to the #2 position with brood faced in so they'll (hopefully) keep tending them after the move, and hopefully they'll relocate the nectar (as they ton't want it out there I assume) and vacate the frame so I can replace it completely without them losing a bunch of brood and food.
Capn, I have not had any problems with bees taking to plastic foundation in the pst and I love its ease of use. I have however noticed IMO that the wax coating from the manufacturer seems so thin it's almost moot, so I've begun to give them a coat of my own wax now before installing into hives. It's still thin as it should be, but it's how I'd like it and I think (hope) they'll take to it better.
Oldbeavo, indeed, I've not seen this problems in any other hives to date, and they are all much stronger than this one.
30, I fed these girls syrup for a month when I got them. They built some comb, but not much. Hence, I was considering replacing the Queen, but it was December, so I didn't think it was fair to judge her performance just yet, plus she wasn't laying very much and I wasn't sure they would survive. She's laying much better now, but the workers just aren't giving her much to work with aside from the middle four frames. That's why I'm trying newly coated foundations that I swapped in, but I was wondering if anyone had seen this or had any ideas as to the cause. Indeed, the bees forage year-round here as our winter's are very mild. I'm at a higher elevation that most on this island, and the coldest we probably see here is about 55F at night in the winter.
We're in the middle of a flow right now. The hive next to this one has exploded its numbers and is filling frames in their deep super very fast right now. I'm tickled about them., however, I do not have a super on this weak hive as they've yet to demonstrate that they're in need of it. They've not touched the outer two frames on either side (#'s 1,2,9,10) and two frames are patchy (#'s3,8). The middle four are in good use, full of brood and food, although they're building a fair amount of bridge comb between frames, despite me ensuring they're spaced properly. I trimmed some during this last inspection and tightened the spacing a smidge...we'll see.
Anyway, I'll give them a few more days before I intrude on them again to apply wax to the patchy frames. Will followup on this thread post-inspection. Further thoughts are welcome from all. Thanks to those who chimed in already.