Termites are major pests of houses and buildings, and also living plants such as agricultural crops, trees in forests, urban areas and gardens. However, in Japan, the basic ecology of termites nesting in living trees is not fully understood. In this study, we observed 255 colonies (nests) of the drywood termite Neotermes sugioi, collected in the field on Okinawa Island, and reported the frequency composition of the reproductive castes, the size of wood with termite gallery, the population size of colonies, and the relative position of the reproductive and non-reproductive castes within nests. Most colonies were headed by a primary queen and a primary king. However, colonies headed only by primary queens, primary kings, or neotenic kings, each accounted for approximately 5% of the colonies. A colony size of 1,000– 4,000 individuals (2058.2 ± 1695.0 [mean ± SD]) was common and the average length of colony branches was less than 100 cm. Queens and kings were found in the same or nearby nest areas, and more predominantly in the central or root side of nest wood areas. The termites may experience colony fragmentation and reproductive loss as a consequence of typhoons. Incipient colonies (i.e., colonies at an early stage of development) were found on 11.3% of branches of Leucaena leucocephala that did not show any obvious signs of infestation. In future research, it will be necessary to update the list of trees damaged by this termite species, compare the damage by tree species, and evaluate the economic impact.

白蚁是房屋和建筑物的主要害虫，也是有生命的植物，如农作物，森林，城市地区和花园中的树木。然而，在日本，尚未完全了解白蚁在活树中筑巢的基本生态。在这项研究中，我们观察到255个殖民地（巢）的枯木白蚁Neotermes sugioi收集在冲绳岛的田野上，并报告了繁殖种姓的频率组成，带有白蚁通道的木材的大小，菌落的种群大小以及巢内繁殖和非繁殖种姓的相对位置。大多数殖民地由首相女王和首相国王领导。但是，仅以原皇后，原国王或新天王为首的殖民地，每个约占殖民地的5％。常见的菌落大小为1,000至4,000个个体（2058.2±1695.0 [平均值±SD]），菌落分支的平均长度小于100 cm。皇后和国王在巢区的相同或附近，主要在巢木区的中央或根部。由于台风，白蚁可能会经历殖民地分裂和生殖损失。没有显示出明显的侵染迹象的银合欢。在未来的研究中，有必要更新被该白蚁物种损害的树木清单，按树木物种比较损害，并评估经济影响。