What is the term for when a new queen takes over an existing colony?

The term "supersedure" refers specifically to the process by which a colony replaces its existing queen with a new one. This occurs when the colony decides that the current queen is not performing adequately, often due to factors like low egg production, aging, or disease. During supersedure, the bees will rear a new queen while simultaneously allowing the old queen to remain in the colony until the new queen is mature and ready to take over. Once the new queen emerges, she may kill the old queen or the old queen may leave the colony. This natural process ensures that the colony continues to function effectively with a healthy and viable queen.

In contrast, swarming involves the colony creating a new queen and leaving with a portion of the worker bees to establish a new colony elsewhere, which is a different context. Succession generally refers to the gradual replacement of one group of organisms with another and does not specifically apply to bees in the same way that supersedure does. Division refers to a method of colony reproduction but typically implies a more drastic separation of the colony rather than a simple queen replacement. Therefore, supersedure is the most accurate term for what happens when a new queen takes over an existing colony.