Final answer:
The phenomenon of a large group of bees leaving a hive with a queen is called 'swarming.' It is a natural part of the reproductive lifecycle of bees that ensures the survival of the species and continuation of their vital pollination services.
Step-by-step explanation:
The term used to describe the phenomenon of a large group of bees leaving a hive with a queen is swarming. Swarming is a natural part of the honey bee's reproductive lifecycle. When a colony becomes too large or crowded, or when the old queen begins to fail, the bees will raise a new queen.
As the new queen matures, the old queen leaves the hive with a large group of worker bees to establish a new colony. This is crucial for the survival of the species as it allows for genetic diversity and the spread of bees to new areas, which is essential for both the health of the bee populations and the plants they pollinate. The phenomenon of swarming ensures the continuation of bee colonies and thus, the critical pollination services they provide to ecosystems and agriculture.
Many honeybee populations are managed by apiarists who provide pollination services for crops, but they are threatened by issues like colony collapse disorder and pesticide use. The loss of honeybees and other pollinators could severely impact the ability to grow crops that require pollination, hence understanding and protecting bee populations is essential for food security and environmental health.