First record of Lithurgus collaris (Megachilidae) from Minamidaito-jima Island, Ryukyu Archipelago.

南大東島は, 琉球列島の沖縄島から360km 東に浮かぶ海洋島である。南大東島において2017 年4 月, 7 月, 9 月にオオハマボウHibiscus tiliaceus ( アオイ科) の訪花動物相調査を実施したところ, シロオビキホリハナバチLithurgus collaris が頻繁に訪花するのが観察された. シロオビキホリハナバチはハキリバチ科の穿坑性種で, 中国, 日本 ( 本州• 九州), 台湾に至る広い分布域を持つ. 琉球列島では中琉球と南琉球に分布することが知られていたが, 南大東島では初めての記録である.Minamidaito-jima Island is an oceanic island located about 360 km east of Okinawa Island, in the Ryukyu Archipelago, Japan. We conducted observational surveys on flower visitors of Hibiscus tiliaceus (Malvaceae) on Minamidaito-jima Island in April, July and September 2017. Lithurgus collaris (Megachilidae) was found visiting the flowers of H. tiliaceus frequently. Lithurgus collaris is a wood-boring bee, and is widely distributed from China, Japan (Honshu and Kyushu) to Taiwan. Although L. collaris has also been known to be distributed in the central and southern Ryukyus, this is the first record of this species from Minamidaito-jima Island