Pattern filogeografici a confronto in specie paleartiche di Coleotteri Scarabaeoidea

Abstract

Biogeographia vol. XXX - 2011 (Pubblicato il 23 dicembre 2011) La Biogeografia della Sicilia Pattern filogeografici a confronto in specie paleartiche di Coleotteri Scarabaeoidea ASTRID PIZZO, DANIELE SILVESTRO, MASSIMILIANO DELPERO, PIERO CERVELLA, CLAUDLA PALESTRINI, ANTONIO ROLANDO Dzjmrtimento di Biologia Animale e a’e[[’U0m0, Universita‘ degli studi di Torino, via Accczdemia Albertina I3, I 0123 Torino (Italy); e—mzzz'Z: ast7*z'd.pz'zzo @um'to.it Keywords: historical biogeography, CO1, ITS2, Nested Clade Analysis, Likelihood-based methods. SUMMARY The present study aims to compare the population structures and the phylogeographic patterns of species be- longing to two different paleartic genus of Coleopteta Scarabaeidae (77ypocopris and Om‘/Jop/azzgms.s.), whose dis- tributions largely overlap, but whose ecological requirements are deeply different. We tested if mitochondrial poly- morphisms (COI gene) of three species of the genus Yiypocopris, I zzlpizzz/5 (Hagenbach), Yipyremzeux (Charpentier) and T z1ermzli5(L.) reflect morphological and geographic subspecies previously recognised; results showed high con- sistency between molecular and morphological/ geographical data, suggesting that the subspecies can be considered as independent evolutionary units. An additional analysis performed with the help of a likelihood based method for historical biogeography allowed us to evaluate the relative influence of demographic factors like genic flow or drift in shaping the particular phylogeographic patterns observed. Both nested clade analysis and likelihood—based historical reconstruction suggested that Sicilian population of T pyremzeu: separated from Peninsular populations only recently and this is likely due to vicariance mechanisms. On the contrary, Ont/rap/mgu: t(Z1I7‘ZlS(SCl’1I'Cl)C[') and O. illyriczts (Scopoli) did not show any phylogeograhic pattern using COI, because of very low (0. tzzurus) or com- pletely lacking (O. z'll}IrirzLs) haplorype polymorphism. A feeble and little informative phylgeographic structure was found using sequences from ITS2. An estimate of the time of interspecific divergence in each genus located speciation events in a time- frame pleaceble in Pliocene. Differences between the patterns observed are interpreted in the light of the different ecological requirements of the species of the two genus. INTRODUZIONE Il presente lavoro si propone di confrontare la struttura di popolazione ed i pattern filogeografici di specie appartenenti a due diversi generi di Coleotteri Scarabaeoidea, T73/pocopris e Ont/cop/mgus (s.s.), che realizzano corologicamen— te areali in larga parte sovrapposti. ll genere Trypocopris comprende sei specie coprofaghe tipiche di pascoli e fo— reste di media ed alta quota: T alpinus (Hagenbach), T azmedei (Fairrnaire), T pyremzeus (Charpentier), T 7/ermzlis (Linnaeus), Tfitlgidus (Motschulsky) e T