Characterization of the Mitogenome of the Genus Dendrocerus Ratzeburg (Hymenoptera: Megaspilidae) with the Specific...

In Hymenoptera, the monophyly of Evaniomorpha has been the focus of debate among different scholars. In this study, we sequenced two mitochondrial genomes of Dendrocerus (Hymenoptera: Megaspilidae) to analyze the mitochondrial genomic features of Dendrocerus and provide new molecular data for phylogenetic studies of Evaniomorpha. The mitogenome sizes of D. bellus and D. anisodontus were 15,445 bp and 15,373 bp, respectively, with the trnG of D. bellus missing. The nucleotide composition was significantly biased toward adenine and thymine, with A + T contents of 81.2% (D. bellus) and 82.4% (D. anisodontus). Using Ceraphron sp. (Ceraphronidae) as reference, the Ka/Ks values of NAD4L and NAD6 in D. anisodontus were both greater than one, indicating that non-synonymous mutations are favored by Darwinian selection, which is rare in other hymenopteran species. Compared with Ceraphon sp. gene order, nine operations were identified in D. anisodontus, including four reversals, four TDRLs (tandem duplication random losses) and one transposition, or four reversals and five TDRLs. Phylogenetic analysis of 40 mitochondrial genomes showed that Evaniomorpha was not a monophyletic group, which was also supported by the PBD values. Ceraphronoidea is a monophyletic group and is a sister to Aulacidae + Gasteruptiidae. Based on the conserved region of the newly sequenced mitochondrial genomes, a pair of specific primers MegaF/MegaR was designed for sequencing the COX1 genes in Megaspilidae and a 60% rate of success was achieved in the genus Dendrocerus.