Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan.
Department of Biology, Faculty of Science, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, 950-2181, Japan.
Sci Rep. 2023 May 31;13(1):8809. doi: 10.1038/s41598-023-36035-1.
Overwintering is a critical part of the annual cycle for species that live in temperate, polar, and alpine regions. Consequently, low-temperature biology is a key determinant of temperate species distribution. Termites are distributed predominantly in tropical regions, and a limited number of species are found in the temperate zone. Here, in the termite Reticulitermes speratus, we report the discovery of an underground chamber that protects kings and queens to survive the winter, which is separate from the one they used during the warmer breeding season. In the spring, the royals inhabited decayed logs on the ground, then moved to their underground chamber located in the roots of stumps in the fall. The winter minimum temperature measured in the royal chamber was higher than that in the logs on the ground. In overwintering termites, the kings and queens had higher cold tolerance than workers and soldiers. Air temperatures dropped below the critical temperature multiple times, as evidenced from the past 140 years of weather records in Kyoto. These results demonstrated the survival strategies of reproductives to overcome the environment at the latitudinal limits. This study helps further the understanding of the termite's seasonal phenology, long-term survivorship, and life cycle.
越冬是温带、极地和高山地区物种年度周期的关键部分。因此，低温生物学是决定温带物种分布的关键因素。白蚁主要分布在热带地区，只有少数几种存在于温带地区。在这里，我们在白蚁 Reticulitermes speratus 中报告了发现一个地下洞穴，它可以保护蚁王和蚁后来越冬，这个洞穴与它们在温暖的繁殖季节使用的洞穴是分开的。春天，蚁王和蚁后栖息在地上腐烂的原木上，然后在秋天移到它们位于树桩根部的地下洞穴中。在皇家洞穴中测量到的冬季最低温度高于地上原木的温度。在越冬的白蚁中，蚁王和蚁后的耐寒性高于工蚁和兵蚁。从过去 140 年京都的天气记录来看，空气温度多次下降到临界温度以下。这些结果表明了繁殖蚁克服纬度限制环境的生存策略。本研究有助于进一步了解白蚁的季节性物候、长期存活和生命周期。
