Five new species of the pill millipede genus Rhopalomeris Verhoeff, 1906 (Diplopoda, Glomerida) from Thailand

Abstract An integrative approach based on morphological characteristics and DNA data from the mitochondrial COI gene has revealed five new species of the pill millipede genus Rhopalomeris Verhoeff, 1906 from Thailand: R. muka Sapparojpattana & Likhitrakarn, sp. nov. , R. lentiginosa Sapparojpattana & Likhitrakarn, sp. nov. , R. dulcia Sapparojpattana & Likhitrakarn, sp. nov. , R. punctata Sapparojpattana & Likhitrakarn, sp. nov. , and R. verhoeffi Sapparojpattana & Likhitrakarn, sp. nov. The five new species are distinguishable from their congeners by distinctive color patterns and telopod structure. The interspecific genetic divergences between the new species and other Rhopalomeris species ranged from 7.86 to 13.71%. Intraspecific genetic divergences within these five species ranged from 0 to 4.53%, with the highest divergences found in R. carnifex and R. verhoeffi sp. nov . This is consistent with both the wide distribution range and the significant intraspecific morphological variations observed in these latter two species. Furthermore, the taxonomic scope of R. carnifex in Thailand is reviewed, and intraspecific morphological variations within R. carnifex and R. verhoeffi sp. nov. are discussed. A distribution map, morphological illustrations from SEM , and an updated key to all known Rhopalomeris species are also provided.