The complete mitochondrial genome of Thaumatosmylus hainanus (Neuroptera: Osmylidae)

Characterization of the complete mitochondrial genome of the Libelloides sibiricus (Neuroptera, Ascalaphidae)

Libelloides sibiricus (Eversmann, 1850) is widely distributed in China, Korea and eastern Russia. To date, few studies have been conducted on this species, with the exception of morphological taxonomy studies. In this study, we sequenced the complete mitochondrial genome (mitogenome) of Libelloides sibiricus, which is 15,811 bp in length, with an overall A + T content of 74.8%, encoding 2 ribosomal RNA genes, 22 transfer RNA genes, 13 protein-coding genes, and a control region. The gene arrangement and components of L. sibiricus are identical to those of most other Neuropteran species. TAA is utilized as the termination codon for most PCGs and TAG for nd1, however, nd6 and atp6 used the incomplete termination codon TA- and cox1, cox2, nd5, cytb had termination codons consisting of only T-. In addition, we selected all known 59 species of Neuroptera from NCBI, and used Sialis hamata, Sialis melania, Sialis longidens and Sialis jiyuni (Megaloptera: Sialidae) as the outgroup. Phylogenetic analysis suggested that the mitogenome of L. sibiricus was the most closely related to L. macaronius and all the owlflies formed the monophyletic group within the superfamily Myrmeleontoidea.

Comparative analysis of five mitogenomes of Osmylinae (Neuroptera: Osmylidae) and their phylogenetic implications

In this study, five mitogenomes of Osmylinae species were sequenced: Osmylus fulvicephalus, Osmylus lucalatus, Plethosmylus atomatus, Plethosmylus zheanus, and Plethosmylus sp. These mitogenomes vary from 15,401 bp to 17,136 bp in size. The nucleotide compositions of Osmylinae mitogenomes are biased towards A/T. The gene arrangement of five mitogenomes is congruent with the putative ancestral pattern of the insects. Most of PCGs initiate with typical start codon ATN and terminate with TAA as the stop codon. All tRNA genes are folded into the typical cloverleaf secondary structure with an exception of tRNA^Ser(AGN). The phylogenetic relationship was reconstructed by both maximum likelihood and Bayesian methods based on 13 PCGs and two rRNA genes. The sister group relationships between Osmylinae and the clade of Spilosmylinae and Protosmylinae were recovered as expected. The monophyly of Osmylinae was corroborated, but within the subfamily, three species (P. atomatus, P. zheanus, and Plethosmylus sp.) originally belonging to Plethosmylus (transferred to Osmylus by Winterton) were restored as a clade and sister to the clade of Osmylus. The current results implied that it is necessary to reassess the systematic status of Plethosmylus in the future.