臺灣研蟲誌 Taiwanese Journal of Entomological Studies 6(2): 13–23 (2021) 稿件收到 Received: 22 March 2021 稿件接受 Accepted: 03 May 2021 稿件出版 Published: 25 June 2021 13 [研究文章 Research Article] http://zoobank.org/urn:lsid:zoobank.org:pub:BD853C3D-DA8F-43FC-9B29-BB9FBCD7F0D8 A Preliminary Phylogenetic Study on the Systematics of Lycocerus Gorham (Coleoptera: Cantharidae) YUN HSIAO 1, 2 1 Australian National Insect Collection, CSIRO, GPO Box 1700, Canberra, ACT 2601, Australia.Email: yunhsiao@outlook.com 2 Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia. Abstract. The genus Lycocerus Gorham, 1889 is a highly speciose group of Asian soldier beetles. Okushima (2005) divided this genus into several species groups and presumed their potential phylogenetic relationship based on anatomical comparison, and a few more species groups were subsequently proposed by various authors. In this study, I reinvestigated the relationship within Lycocerus using phylogenetic analyses of morphological data and extended the taxa sampling to corroborate all currently known major lineages. The resulting topology only partially agrees with Okushima (2005), but supports the synonymy of Athemus Lewis, 1895, Athemellus Wittmer, 1972, Mikadocantharis Wittmer & Magis, 1978, Andrathemus Wittmer, 1978 and lsathemus Wittmer, 1995 with Lycocerus. Key word: Soldier beetles, Cantharinae, systematics, morphological phylogenetics, Asia Introduction Cantharidae is a diverse elateroid beetle family with a brightly colored soft-body, originating from the Late Jurassic and maintaining the high rate of diversification since then (McKenna et al., 2019). Lycocerus Gorham, 1889 is a highly species-rich Asian genus of soldier beetles, with more than 300 species distributed in the Oriental and eastern Palaearctic regions (Kazantsev & Brancucci, 2007). Okushima (2005) revised the Japanese fauna and summarized nine major species groups with a couple of subgroups based on both external and genitalic characters. Subsequently, four species groups of Lycocerus were established, including the L. michiakii Group based on species from Laos (Okushima & Brancucci, 2008), the L. hickeri Group based on species from China and Vietnam (Yang et al., 2014), the L. rhagonychiformis Group based on the Taiwanese species (Hsiao & Okushima, 2016), and the L. fainanus Group based on species from China, Taiwan and Vietnam (Okushima & Hsiao, 2017). Currently, most research on Lycocerus was predominantly focused on the alpha and beta taxonomy, with only few studies attempting to approach the issues of systematics. Okushima (2005) assumed the phylogeny of Lycocerus based on the comparative anatomy, and Hsiao et al. (2016) attempted to reconstruct the Lycocerus phylogeny using a cladistics analysis based on 29 adult traits and geographic distribution, covering all proposed species groups. Nonetheless, the main purpose of the phylogenetic analysis in Hsiao et al. (2016) aimed to clarify the systematic placement of some species related to the L. hanatanii Group and the relationship among most species groups was unresolved. In the present study, I reanalyze the relationship within Lycocerus to examine the phylogenetic hypothesis in Okushima (2005). Also, I include all genera and subgenera synonymized with Lycocerus by Okushima (2005) to test this taxonomic treatment. Material and methods Taxon sampling and character selection The ingroup contained 15 species, representing all known species groups (Table 1). Lycocerus pallidulus (Wittmer) of L. maculicollis Group and L. japonicus (Kiesenwetter) of L. lineatipennis Group were also selected representing lsathemus Wittmer and Mikadocantharis Wittmer & Magis. Two species of Themus Motschulsky, namely Th. (Th.) nobilis nobilis (Gorham) and Th. (Telephorops) sauteri (Pic), were used as outgroups. The data matrixes from Okushima (2005) and Hsiao et al. (2016) were used as a starting point for morphological character coding. After reconsideration of characters used in previous phylogenies of Lycocerus, 21 characters were kept, seven were amended, four were added and one was deleted to obtain a matrix pertinent to the taxa included in analyses. No geographic character was used. In total, 46 adult characters were coded for the phylogenetic analysis (Tables 2, 3). I assembled the matrix using MESQUITE v. 3.61 (Maddison & Maddison, 2019). Inapplicable data were scored as ‘-’ in the character matrix.