Re: Queenless hive rejects grafts
As per above, but also, grafts are not always accepted even in the best prepared cell starting colonies. If the plastic cells are brand new and have never been in a hive, you will get better results after they have been in a hive and cleaned by the bees for a while.
The way forward will be to find out for certain if this colony will build queen cells by giving them a frame of eggs / young larvae & seeing what happens. If they don't build queen cells you have a queen or laying workers. If they do build queen cells, kill them and continue you grafting efforts till you succeed.
44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).