The distribution of the tramp ant Technomyrmex brunneus was surveyed on Amami-ôshima, Central Ryukyu Islands, Japan during 2017 to 2020. The inva- sion of this species into forests was monitored by checking traps set for mongoose control, in which for- agers and nests were often found. At 320 among a total of 18,963 trap sites this species was found. In three other parts of the island the presence/absence of this species was also confirmed at 58 sites 200 m to 1 km apart along roads. Our survey revealed the recent is- land-wide expansion of this species in both rural areas and forest interiors. Even in natural and semi-natural forests like Kinsakubaru, Kamiya etc. it occurred on the forest floor under closed canopies as well as in for- est gaps. Although at present we have no direct evi- dence of the negative effect of this species on ecosys- tem, it is quite possible that it would have serious damage to arboreal ant communities.

奄美大島におけるアシジロヒラフシアリ Technomyrmex brunneus Forel の分布(山室一樹・金井賢一・福元しげ子・山根正気)