Winter temperature in the exposed nest of Japanese honeybee, Apis cerana japonica.

摘要

A natural nest of a feral colony of Japanese honeybee, Apis cerana japonica was found in suburb area in Chiba Prefecture, Japan. It was built on the wall of a house exposed to open air. Its nest temperature was recorded during winter season for 5 months and the results show how honeybee colonies manage to survive cold winter even when they nested in an open space. Nest temperature was changed little while the colony was preparing for winter. In mid-winter the inside temperature became unstable. Then it recovered after severe cold. The wintering of the colony was divided into 5 phases from pre- to post-wintering by the range of temperatures inside the nest. During the deepest wintering phase honeybees probably ceased brood rearing and accurate thermoregulation to reduce the energy consumption and exhaustion of workers. This may be an adaptation enabling the bees to survive cold winters.