A Phylogenetic Morphometric Investigation of Interspecific Relationships of Lyponia s. str. (Coleoptera, Lycidae) Based on Male Genitalia Shapes.

Simple Summary: Resolving phylogenetic relationships among animals remains one of the most challenging issues in systematics. Currently, molecular phylogeny is the standard for inferring evolutionary relationships, but morphological analysis still cannot be replaced or neglected. Male genitalia have been proven to be valuable in phylogenetic analyses usually in the higher taxonomic grades but are rarely studied at the lower level. In the present study, we performed a taxonomic review (with two new species described) and further investigated the interspecific relationship of Lyponia s. str. based on the morphometric data of phallus shapes using geometric morphometric (GM) and phylogenetic morphometric (PM) methods. As a result, the produced topologies (of the unweighted pair group method using arithmetic averages (UPGMA), neighbor-joining (NJ) and maximum parsimony (MP) analyses) provide a general framework of the morphological evolution of this subgenus. To be exact, these species are divided into two clades that represent two shapes of the phallus. The results provide better understanding of the species diversity and evolution of Lyponia s. str. and shed new light on investigations of the phylogenetic relationships of insects based on male genitalia shapes, which is particularly useful when molecular data are unavailable. The nominate subgenus Lyponia Waterhouse, 1878 from China is reviewed, with two new species described and named L. (s. str.) ruficeps sp. n. (China, Yunnan) and L. (s. str.) zayuana sp. n. (China, Xizang). A distribution map and a key to all species of Lyponia s. str. are provided. Moreover, the phenotypic relationships among the species of Lyponia s. str. are investigated based on phallus shapes using geometric morphometric and phylogenetic morphometric analyses. The topologies demonstrate that the species are divided into two clades. One clade is composed of six species (L. ruficeps sp. n., L. zayuana sp. n., L. kuatunensis, L. shaanxiensis, L. hainanensis, and L. tamdaoensis) and is supported by a stout phallus (less than 3.6 times longer than wide). The other clade includes the remaining species (L. nepalensis, L. debilis, L. cangshanica, L. delicatula, and L. oswai) and is supported by a slender phallus (at least 4.1 times longer than wide). These results provide better understanding of the species diversity and evolution of Lyponia s. str. Nonetheless, more samples and loci are required in the future to verify the present results. [ABSTRACT FROM AUTHOR]