Substitution Rate Estimation of Molecular Markers to Evaluate Evolutionary Aspects in Ladybird Beetles

In this study, we examined the ribosomal DNA internal transcribed spacers and mtDNA markers for their use in the prospecting of 480 ladybird species belonging to 14 tribes to assess the evolutionary topology and substitution rates. Substitution patterns of the respective markers were estimated using a cascade of algorithms such as pairwise sequence comparisons, maximum likelihood estimates of the substitution matrix, transitions/transversions (ti/tv) and gamma parameters with a suitable substitution model. Maximum likelihood (ML) estimates showed that COI (R = 1.16) and COII (R = 1.36) were more biased towards transitions. COI has a higher ti/tv ratio indicating more substitutions and less divergence among the species in the phylogenetic tree, though it had moderate bootstrap support. ML and Bayesian analysis were used to construct the morphology character matrix and molecular datasets in order to establish the evolutionary relationship. All the characters of male and female genitalia supported mophyletic topology. The phylogenetic results of molecular datasets suggest that most of the taxa significantly support monophyly. Phylogenetic analysis depict COI consists of more substitution as it shows less divergence among species.