Molecular Phylogeny Of Lucanidae From China (Coleoptera:Scarabaeoidea)

Lucanidae is one of the earliest branching lineages of Scarabaeoidea (Insecta: Coleoptera). The common name of stag beetle is derived from the large and striking mandibles in males. Most of stag beetles have distinctly sexual dimorphism and male polymorphism, which usually caused the intraspecific differences and interspecific similarity. Many amateur entomologists often overlooked these traits and named numerous so-called "new species and subspecies". A lot of problematic genera and species need to be clarified in this family. In addition, there has been an argument about the higher system of Lucanidae for a long time.In this study, we tried to explore the phylogeny of Lucanidae using molecular systematic techniques.26 genera including 103 species (or subspecies) from Chinese fauna were analysed (mitochondrial COI,16S rDNA, nuclear Wingless and 28S rDNA). Totally over 500 sequences were amplified, sequenced and aligned of the four genes and other alternative genes. We conducted a phylogenetic analysis by using MP, ML and BI methods based on the combined sequences of the four genes.As the results, the phylogeny tree exhibited a monophyly of Lucaninae. At the subfamily level, the Syndesinae is recovered as paraphyletic. The genus of Sinodendron is the most primitive group in Lucanidae from Chinese fauna, which should be treated as an independent subfamily Sinodendroninae. At the tribe level, the phylogenetic relationships among the ten Chinese Lucanidae tribes are Sinodendrini+ ((Ceruchini+Lamprimini)+((Platycerini+Aesalini)+(Figulini+(Lucanini+ (Dorcini+(Odontolabini+Aegini)))))). At the generic level, the genus Odontolabis is sister group of Neolucanus; the relationship of Pseudolucanus, Lucanus and Noseolucanus still need further research; the current genus of Prosopocoilus is a paraphyly, which is close relative to Rhaetulus, Hexthrius, Rhaetus, Pseudorhaetus and Dorcus (s.l.).Additionally, we sequenced, annotated and analyzed the mitochondrial genomes of 8 species representing 7 genera of Lucanidae (6 completed mitochondrial genomes and 2 partial genomes). The gene orders of most of them are identical to that of the putative ancestral arrangement of insects, while a trnL rearrangement occurred in the mtgenome of Sinodendron yunnanense. Three of them have a poly (A/T) stretch within their control regions. A phylogenetic analysis for 18 species of Scarabaeidae (others from Genbank) is conducted based on protein-coding genes. The main topological structures are consistent with the results obtained from the four genes.Moreover, a time-calibrated phylogeny tree obtained from BEAST based on four fossil data estimated the origin of crown group Lucanidae from China as circa 130 million years ago (Mya), and indicated that rapidly speciation occurred during Oligocene.