New insight into the systematics of Heteromurini (Collembola: Entomobryidae: Heteromurinae) with special reference to?Alloscopus?and?Sinodicranocentrus?gen.n.

摘要

Classification of Heteromurini represented by?Heteromurus?and?Dicranocentrus?is currently under debate due to the presence of 5 or 6 antennal segments, respectively. Among the Heteromurini,?Alloscopus?is traditionally considered to be closely related to?Heteromurus?but its phylogenetic position is challenged by recent molecular evidence. A multilocus molecular phylogeny and topology tests conducted here indicate the closer relationship of?Alloscopus?and?Dicranocentrus, and one non-Dicranocentrus?basal group,?Sinodicranocentrus?gen.n.?Two new species,?Alloscopus bannaensis?and?A. liuae, are described from southern China. Intact tergal chaetotaxy including macrochaetae, microchaetae and S-chaetae is illustrated in?Alloscopus?for the first time. A new genus?Sinodicranocentrus?gen.n. is also erected based on the unique paired outer teeth on unguis and S-chaetotaxic pattern. Transformation among S-chaetae on the fifth abdominal tergite is presented to further illuminate the possible relationships among Heteromurini taxa. Main distinguishing characters used in the classification of Heteromurini and the phylogenetic position of supraspecific taxa are discussed. Comprehensive keys to the genera of Heteromurini and the species of?Alloscopus?are provided. This study provides the new insight into the relationships among Heteromurini genera and highlights the great systematic values of intact tergal chaetotaxy within the tribe.