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

Abstract

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. © Senckenberg Gesellschaft für Naturforschung, 2020.