Molecular Phylogenetics Of Dexiini (Tachinidae: Diptera) From China Based On 28S RRNA Gene And COI Gene Sequences

Dexiini is a large group of the Dexiinae (Diptera Tachinidae) with a world widedistribution that contain all continents and most major islands. Its flies life historiesare exclusively endoparasitic on larval of Coleptera and Lepidoptera. Thus they playsignificant roles as natural enemies of herbivorous ecological communities.Dexiinae as a taxonomic classification are characterized by the similar gemelstructure of its male terminalia. In this study, we use molecular technologies thatamplificate and sequence 28S rRNA genes and COI genes from 37 species flies. BI,ML, NJ and MP phylogenetic trees were reconstructed for a phylogenetic analysis ofof Dexiini. The results show that the base of 28S rRNA genes and COI genes obviousbias to A+T in the 37 species and the average proportion of base contain isrespectively T=36.3%, 38.6%; C=11.3%, 15.2%; A=37.0%, 30.7%; G=15.4%, 15.5%.Ts+Tv between 28S rRNA gene and COI gene are 0.000-0.179 and 0.002-0.218between different genera of Dexiini. Two sequence genetic distance showed thatdifferent species in genus are comparatively small, and the average genetic distance ofBillaea, Dexia, Dinera and Estheria are 0.056, 0.086, 0.105 and 0.081, respectively.The topology of phylogenetic trees show very similar results. The relationshipbetween tribes, genera and species is definite, and proved that 28S rRNA gene andCOI gene are useful for inferring phylogenetic relationships in Dexiini and Dexiinae.In this study, molecular phylogenetic analysis show that Dexiinae is monophyly. Therelationships for the genus of Dexiini show that Trixa is as a sister group to Dexia andThelaira. Estheria and Prosena are found to be monophyletic, Billaea and Dinera arefound to be monophyletic, their relationships can be summarized that Estheria andProsena are as a sister group to Billaea and Dinera. We suggest that genus of Thelairabelonging to Dexiini, and as a sister group to Dexia. Dinera fuscata is independent, itsclassification status should be subject to the morphological and molecular data for thefurther analysis. The relationship of Tachinidae can be summarized as Dexiini +(Exoristinae + (Tachininae + Phasiinae)).