Two new species of the dwarf centipede genus Nannarrup Foddai, Bonato, Pereira & Minelli, 2003 (Chilopoda, Geophilomorpha, Mecistocephalidae) from Japan

The genus Nannarrup Foddai, Bonato, Pereira & Minelli, 2003 is a monotypic genus established on the basis of the possibly introduced species N.hoffmani Foddai, Bonato, Pereira & Minelli, 2003, from New York, USA. In the present study, in a field survey conducted throughout Japan, Nannarrup-like specimens were collected from Honshu, Shikoku, and Kyushu. These specimens clearly showed the diagnostic characteristics of the genus but were morphologically distinct from N.hoffmani. Furthermore, morphological analysis and DNA barcoding revealed that these specimens could be assigned to two distinct undescribed species. On the basis of these results, N.innuptus Tsukamoto, sp. nov. and N.oyamensis Tsukamoto, sp. nov. are described. The three Nannarrup species can be distinguished from each other on the basis of the following combination of characteristics: presence or absence of a pair of smooth or weakly areolate areas along the posterior part of the paraclypeal sutures; the width-to-length ratio of the denticle on the trochanteroprefemur; the pigmentation of the denticle on the tarsungulum. Moreover, the field survey resulted in the collection of exclusively female specimens of N.innuptus Tsukamoto, sp. nov., which shows the possibility of parthenogenesis of this species.