Not having one-day-old larvae suppresses emergency queen production! Give that one a mated queen in a Laidlaw cage pronto!
Only other thing is maybe they have a queen who is holding up on laying for a while - how are conditions? Do they have pollen stores? Without pollen, many queens will not lay eggs, as the brood needs the protein in their royal jelly. Many a beek interprets this and queen failure. It is probably better interpreted as beekeeper failure!
Check them carefully for a queen, run a queenless test. Put a caged, mated queen on top of the frames. If they flock to her and adore her and feed her, they are queenless. If they ignore her or form an attack ball, they have a queen. If they are queenless, add that mated queen under a Laidlaw push-in queen introduction cage.
Only other thing is maybe they have a queen who is holding up on laying for a while - how are conditions? Do they have pollen stores? Without pollen, many queens will not lay eggs, as the brood needs the protein in their royal jelly. Many a beek interprets this and queen failure. It is probably better interpreted as beekeeper failure!
Check them carefully for a queen, run a queenless test. Put a caged, mated queen on top of the frames. If they flock to her and adore her and feed her, they are queenless. If they ignore her or form an attack ball, they have a queen. If they are queenless, add that mated queen under a Laidlaw push-in queen introduction cage.