A list of Yuukianura Yosii, 1955 species of the world (Collembola: Neanuridae: Neanurinae: Lobellini), with description of a new species of unusual ecology from Santo Island (Vanuatu)

We redefine the genus Yuukianura Yosii, 1955, and we give an updated list of its nine species. Four of these species initially described in other genera are transferred to Yuukianura: Lobella (Lobella) yasudai Yosii, 1966, Lobella pacifica Yosii, 1971, Protanura hawaiiensis Bellinger & Christiansen, 1974, and Pseudocolonavis rosea Kim & Lee, 2000. Two species described as Yuukianura (Yuukianura cavicola Yosii, 1956 and Y. nomurai Yosii, 1956) are considered as Lobellini incertae sedis. A new species, Yuukianura judithae n. sp., is described from Santo Island in Vanuatu, Melanesia. It differs from other species of the genus by a combination of characters including total lack of eyes, two chaetae on the ocular tubercle (Ocp absent), (5 + 5) dorsal chaetae on Th. I, (3 + S) chaetae in chaetal group DL of Th. II-III, two chaetae in group Di of Abd. I-IV (Di3 absent) and untoothed claw. The species also shows three characters unusual for Neanurinae Boerner, 1901: a strong reduction of tibiotarsal chaetotaxy, the absence of macrochaeta De1 on Abd. I-IV and the presence of conspicuous buttonhole structures dorsally on head, Abd. I and Abd. IV. The new species occurs in both forest and cave habitats, not in mangrove or seashore habitats, in contrast to most members of the genus. In caves, it often lives in large number on guano piles of bats or swiftlets, and is the first record of a Neanuridae Yosii, 1956 in such an habitat.