There are 3 frames with brood in the same pattern. It all is domed like in this photo which made me think it was all drone brood.About 60% myself . Cannot tell if domed cells or just shallow cells from converted honey cells. Cells are only as tall as bottom bar. Is that the cluster or are there other frames with brood and bees?
I definitely don't think nutrition is the issue. The frames on both sides of the brood nest are pretty solidly packed with honey and pollen (six frames of honey at least). I treated this hive with formic acid the first week of September (I live in a warm climate) and the mite counts were at 2/300 following the treatment using the sugar roll method (including a 2 min rest after shaking and dissolving the sugar in water to count mites). They were at 8/300 prior to the treatment. In November I treated them with an oxalic vape without doing a count, just because they were broodless and the risk is low with said treatment).pretty sure there is some worker brood in that pic. However the pattern definitely doesn't look all that great. I would say that is from a queen although she might be running out of steam, nutrition could be low in general in the hive (honey and pollen reserves) causing nurse bees to eat the eggs, or possibly Varroa is reaching high levels. Need more info though such as last known mite count or last mite treatment and what you used. Also status of stores in the hive.
I'll see what I can do about finding a queen. I did put a mated queen on top of the frames and they responded positivity to her fanning and such which seemed weird if they have a queen.That brood pattern is too solid for laying workers. Solid brood patterns like that can be confusing, as the domes can appear somewhat flat. Best way to assure if that is drone or worker brood is to scratch a few caps open and examine the pupa. You likely have a drone laying queen. Possible that they tried to replace the queen after the Formic treatment and she didn't mate. If you can't find her, try shaking all the bees thru an excluder. You'll need to eliminate her.
At that point, you can correct the problem as you see fit, with a frame of brood with eggs from which they'll pull a queen cell, adding a grafted queen cell, adding a purchased queen, or combining with another hive.
Ps. There is never "a" laying worker. When a hive goes laying worker, most of the bees in the hive are laying workers.
I do not understand the dynamics of LW prevention in a winter hive. I accept brood in a summer hive prevents LW, there is no brood in a winter hive so more is going on or most hives would come out of winter LW. Not sure how that plays out in the transition from winter to spring.I'll see what I can do about finding a queen. I did put a mated queen on top of the frames and they responded positivity to her fanning and such which seemed weird if they have a queen.
I've basically done the same thing with a screen bottom board. Use it to separate the bottom colony from the top. After a week, most of the bees in the bottom hive slowly relocated to the top queen rite colony and no issue just removing it. One time they didn't relocate, and I found a virgin queen in there(not sure where she came from)Last year on 5/7/19 we found one our colonies had gone LW. To fix it, we removed the honey supers and put a Snelgrove board on top of the LW brood boxes then placed a single queen right box on top of it. ( a swarm we had caught) Opened a top door on the snelgrove for an entrance for the top colony. Left it like this for about 3 weeks to allow the open brood pheromone from the top to drift through the lower LW brood boxes, then opened a door right below the top entrance and allowed the bees to mingle for another week. We then pulled the snelgrove board out and let it be one colony. I've read it takes about 3 weeks with open worker brood pheromone for the LW ovaries to reset.
Worked great, no more laying workers, got a fair honey harvest and this year it is one of our strongest hives coming out of winter.
You do need a single QR hive to this but it saves resources from not pulling brood from your other hives for 3 weeks. Probably to cold to do this now but later,you might give it a try.