In May 2012 Rotuma Island, the main island of the remote Rotuma Group (Fiji), was surveyed to document the
composition of the non-native land snail fauna and to investigate if populations of previously recorded native land snail
species persist. From sampling at nine locations, twenty-one land snail species from eleven gastropod families were
found. Of these, eight species are non-native and two of these Parmarion martensi Simroth, 1893 and Quantula striata
(Gray, 1834) (Ariophantidae) are new records for the Rotuma Group. Ten of the 13 species of native land snails found
— including the endemic partulid Partula leefi E. A. Smith, 1897 and the rhytidid Delos gardineri (E. A. Smith, 1897)
— were detected only as empty shells. The native Ouagapia perryi (E. A. Smith, 1897) and the endemic Succinea
rotumana E. A. Smith, 1897 and Sinployea rotumana (E. A. Smith, 1897) remain undetected on Rotuma Island since
their first collection in 1897. The non-native, invasive predatory flatworm, Platydemus manokwari, was also found and
represents a major threat to the island’s land snail fauna. This non-native species appears to be absent in many other
parts of the Fiji Island archipelago and thus a re-evaluation of existing quarantine measures is required to address its
potential spread to non-invaded areas. Comparisons with earlier surveys indicate a shift in the structure of the Rotuman
land snail fauna over a 115-year period, with declining native components and increasing prevalence of non-native
species. Further sampling, focusing on residual native habitat in less accessible areas such as coastal cliffs and offshore
islets, is urgently needed to establish the conservation status of Rotuman native land snails and determine the
threat posed by both, non-native snails and P. manokwari.
XV.—New species of Tabanidæ from Australia and the Fiji Island
