Phylogenetic Analysis Of Bittacidae Based On Morphological Characters And Molecular Data With Descriptions Of Species

Bittacidae is an important relic family of Mecoptera.The adults are unable to stand on a surface because of their having three pairs of raptorial legs.They usually use their prehensile tarsi to hang themselves from the edge of leaves or twigs of plants.As the second largest family in Mecoptera,Bittacidae comprises more than 200 species in 20 extant genera,but the rationality of several genera remains controversial.A rational systematics should be based on a phylogenetic analysis.Although some phylogenetic analyses have been conducted for Mecoptera,the phylogeny of Bittacide received little concern.Therefore,a phylogenetic analysis of Bittacidae is desirable.In this study,a phylogeny of 77 species in 18 genera is reconstructed in Bittacidae based on 92 morphological characters of male adults,using maximum parsimony with Microchorista philpotti(Tillyard,1917),Nannochorista neotropica Navás,1928 and N.holostigma Tillyard,1917 in Nannochoristidae as outgroups.The analysis was performed using TNT 1.1 and WinClada 1.00.08 combined with NONA 2.0.Furthermore,based on two mitochondrial gene fragments(COI and COII)and two nuclear gene fragments(28S and EF-1?),we reconstructed a phylogeny among 31 species of six genera in Bittacidae using maximum likelihood and Bayesian inference with Nannochorista dipteroides Tillyard,1917 and N.neotropica Navás,1928 in Nannochoristidae as outgroups.Maximum likelihood used raxmlGUI 1.3,Bayesian inference used MrBayes 3.1.2.The phylogenetic analysis of Bittacidae using morphological characters shows that the following genera are monophyletic,including Bicaubittacus Tan & Hua,2009,Eremobittacus Byers,1997,Harpobittacus Gerstaecker,1885,Issikiella Byers,1972,Kalobittacus Esben-Petersen,1914,Nannobittacus Esben-Petersen,1927,Neobittacus Esben-Petersen,1914,Pazius Navás,1913 and Terrobittacus Tan & Hua,2009.Among them,Issikiella,Kalobittacus,Nannobittacus and Pazius form a monophyletic group;Terrobittacus has more closely phylogenetic relationship with the Chinese bittacids.The monotypic genera Anabittacus Riek,1954,Orobittacus Villegas & Byers,1981 and Tytthobittacus Smithers,1973 were placed as basal genera of Bittacidae.As the most widespread genus in Bittacidae,Bittacus is reconfirmed to be a paraphyletic group,and needs to be reclassified based on the phylogenetic relationship.Bittacus capensis(Thunberg,1784),B.kimminsi Tjeder,1956,B.milleri Londt,1978,B.selysi Esben-Petersen,B.smithersi Londt,1972,1917 and B.sobrinus Tjeder,1956 have closely relationships with Harpobittacus.B.alexanderi Byers,1999,B.banksi Esben-Petersen,1915,B.mexicanus Klug,1838 and B.sylvaticus Byers,1996 form a monophyletic clade.Based on the analysis of molecular systematics,Bittacus is paraphyletic.B.punctiger Westwood,1846,B.stigmaterus Say,1823,Bittacus walkeri Esben-Petersen,1915,B.selysi and Harpobittacus australis(Klug,1838)have close relationships.The Chinese Bittacus,Bicaubittacus appendiculatus(Esben-Petersen,1927)and B.strigosus Hagen,1861 form a monophyletic group.Terrobittacus is well supported again for their monophyly and can be divided into two principal clades.T.angustus Du & Hua,2017,T.longisetus Tan & Hua,2009 and T.rostraus Du & Hua,2017 form a clade;T.echinatus(Hua & Huang,2008),T.implicates(Huang & Hua,2006)and T.xiphicus Tan & Hua,2009 form another clade.In addition,nine species in three genera of Bittacidae are described and illustrated,including three new species,i.e.Terrobittacus rostratus Du & Hua,2017,Terrobittacus angustus Du & Hua,2017 and Bittacus acutus sp.nov..Three species,Bicaubittacus burmanus(Tjerder,1973)rec.nov.and Bittacus ussuriensis Plutenko,1985 rec.nov.are first recorded from China.Bittacus diaoluoshanus Chen & Hua,2011 rec.nov.is first recorded from Vietnam.