Samplings of Millipedes in Japan and Scarab Beetles in Hong Kong result in five new Species of (Nematoda: Diplogastridae).

The authors describe five new species of from Japan and Hongkong. Scarab beetle samplings in Hongkong identified sp. n. and sp. n., representing the first beetle-associated species from China. Surprisingly, samplings of millipedes in Japan revealed a previously unknown association of nematodes with these arthropods. Specifically, the authors found three previously known species, , , and on Japanese millipedes. In addition, the authors found three new species on millipedes, which are described as sp. n., sp. n., and , sp. n., the latter of which was also found on stag beetles. These species are most closely related to , , and and belong to the species-complex. The authors describe all species based on morphology, morphometrics, and genome-wide sequence analysis. Mating experiments indicated that all species are reproductively isolated from each other and in contrast to the species of the " species-complex " they do not form F1 hybrids. The authors describe five new species of from Japan and Hongkong. Scarab beetle samplings in Hongkong identified sp. n. and sp. n., representing the first beetle-associated species from China. Surprisingly, samplings of millipedes in Japan revealed a previously unknown association of nematodes with these arthropods. Specifically, the authors found three previously known species, , , and on Japanese millipedes. In addition, the authors found three new species on millipedes, which are described as sp. n., sp. n., and , sp. n., the latter of which was also found on stag beetles. These species are most closely related to , , and and belong to the species-complex. The authors describe all species based on morphology, morphometrics, and genome-wide sequence analysis. Mating experiments indicated that all species are reproductively isolated from each other and in contrast to the species of the “ species-complex ” they do not form F1 hybrids.