The most successful way to introduce a queen is with a Push-In Cage. Fill the exit tunnel with queen candy, push the cage into a frame in the center of the brood nest with open cells and brood about to emerge (no adult bees), and relesae the queen and attendant workers into the large 5 3/4" by 5 1/8" cage. As the queen starts to lay eggs she will give off queen pheromone, which will insure acceptance. Putting the cage over the soon to emerge brood insures nurse bees to care for the new queen. The bees can release her or you can manually do so after she has started laying. Reduce to 9 frames to give more space for bees to crawl on the cage. Also can be used to isolate the queen.
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