Most (but not all) "queenless" hives have a virgin queen who will start laying any day and who will kill any queen you try to introduce. The best soution is open brood so they can start a queen if they need one, the laying workers won't take over and it won't interfere with a virgin queen. Plus you won't waste your money on a queen who will only get killed.
http://www.bushfarms.com/beesmath.htm
http://www.bushfarms.com/beesfallaci...nobroodnoqueen
There are few solutions as universal in their application and their
success than adding a frame of open brood every week for three weeks.
It is a virtual panecea for any queen issues. It gives the bees the
pheromones to suppress laying workers. It gives them more workers
coming in during a period where there is no laying queen. It does not
interfere if there is a virgin queen. It gives them the resources to
rear a queen. It is virtually foolproof and does not require finding a
queen or seeing eggs. If you have any issue with queenrightness, no
brood, worried that there is no queen, this is the simple solution that
reuires no worrying, no waiting, no hoping. You just give them what
they need to resolve the situation. If you have any doubts about the
queenrightness of a hive, give them some open brood and sleep well.
Repeat once a week for two more weeks if you still aren't sure. By then
things will be fine.