Whenever a new queen is introduced to the existing colony there is always a chance your worker bees will not accept her, and the result of this could be the death of your new queen – no matter which method of introduction you use.
The main things you need to be sure of when introducing a new queen, whether it be into a full colony or nucleus, is that you do not have a virgin queen or indeed a mated queen that has simply gone off lay in your colony. You need to ensure you have removed all queen cells or queen cups, shake the bees off the frames if necessary to find the queen cells they hide in the edges of the frames. Also ensure you do not have laying workers in your hive.
Read full article here: Introducing Queens — Lytchett Bay Apiaries