Abstract
The Japanese honeybee population on Amami Oshima Island represents the southern distributional limit of the species, and is thought to be hereditarily isolated from the mainland population. To obtain basic ecological information for conserving the honeybee on Amami Oshima, we compared the nesting conditions, natural enemies, disease symptoms, and variation in body size of the species between Amami Oshima, Kyushu, and Iwate Prefecture. We also investigated worker bee foraging activity and the activities of the reproductive caste in tree hollows in a subtropical laurel forest and in village gravestones during the reproductive season. Bees on Amami Oshima were significantly smaller than those in Kyushu and Iwate Prefecture, but we found no natural enemies or diseases strongly influencing the population. Worker bee foraging and reproductive caste activity depended on the weather. In particular, rainy or windy days inhibited bee foraging and might restrict the rate of colony development. Approximately half of the colonies we observed occurred in the hollows of large trees, and we twice observed swarming of subtropical forest colonies. Therefore, protecting wooded areas with large deciduous trees is important for conserving honeybees on Amami Oshima.
