The mitochondrial genomes of the barklice, Lepinotus reticulatus and Dorypteryx domestica (Psocodea: Trogiomorpha): Insight into phylogeny of the order Psocodea

Complete mitochondrial genome of Stethoconus japonicus (Hemiptera: Miridae): Insights into the evolutionary traits within the family Miridae

The mitochondrial (mt) genome sequence of insects possesses numerous evolutionary traits. To better understand the evolution of mt genomes within the family Miridae, the complete mt genome of the predatory Japanese plant bug Stethoconus japonicus Schumacher was sequenced before undertaking a comparative analysis of all reported plant bug mt genomes. The mt genome of S. japonicus is a closed-circular and double-stranded DNA molecule of 16,274 bp (GenBank: MK341530), which consists of 13 protein-coding genes (PCGs), 2 rRNAs, 22 tRNAs and a putative control region (CR). Consistent with other plant bugs, the mt genome of S. japonicus is strongly AT-biased (73.49 %) with A-skewed (0.202) and C-skewed (-0.248). All 13 PCGs initiate translation using ATN codons and TAA served as complete stop codons for eight PCGs, which as incomplete stop codon "T-" for cox1, nad1, nad5-6 and "TA-" for cox2. Regarding other features, all 22 tRNAs could be folded into typical cloverleaf secondary structures. The control region is 1,717 bp and contains a long tandem repeat sequence of a 165 bp unit repeated six times. Similar sequence with variable number of tandemly repeated units from intra-genus CRs is a distinct characteristic of plant bug mt genomes. Phylogenetic relationships of 15 bugs were eventually analyzed based on Maximum likelihood (ML) and Bayesian inference (BI) methods using 17 mt genome sequences. In the phylogenetic trees, species from a same genus or subfamily are clustered into a branch with high supporting values.and the result suggest that Deraeocorinae is more closely related to Mirinae than Bryocorinae. Finally, this study revealed that mutation of tRNA anticodon is a useful phylogenetic marker that could be of significance for studies of evolutionary patterns.

Contribution to the Knowledge of Dicranoptychini (Diptera, Tipuloidea, Limoniidae) in China, with the First Mitochondrial Genome of the Tribe and Its Phylogenetic Implications

Dicranoptychini is a tribe in the subfamily Limoniinae (Diptera, Tipuloidea, and Limoniidae) and includes only the genus Dicranoptycha Osten Sacken, 1860. However, the species diversity of the tribe in China was seriously underestimated, and the taxonomic status of Dicranoptycha has long been controversial. In this study, types of Chinese Dicranoptycha species and specimens collected from several localities in China were examined, and the first mitochondrial (mt) genome of the tribe Dicranoptychini is presented. Two Dicranoptycha species, D. jiufengshana sp. nov. and D. shandongensis sp. nov., from China, are described and illustrated as new to science. A Palaearctic species, D. prolongata Alexander, 1938, is recorded in China for the first time. In addition, the complete mt genome of D. shandongensis sp. nov. is sequenced and annotated, indicating that it is a typical circular DNA molecule with a length of 16,157 bp and shows a similar gene order, nucleotide composition, and codon usage to mt genomes of other Tipuloidea species. The two pairs of repeat elements are found in its control region. Phylogenetic results confirm the sister-group relationship between Cylindrotomidae and Tipulidae, question the position of the genus Epiphragma Osten Sacken, 1860 in Limoniidae, and indicate that Dicranoptychini may be a basal lineage within Limoniinae.

Characterization of the complete mitochondrial genome of a barklouse, Lepinotus sp. (Psocodea: Trogiomorpha: Trogiidae)

Barklice in the genus Lepinotus (Psocoptera: Trogiidae) are small, soft-bodied stored-product pests that are difficult to control. We sequenced and annotated the mitochondrial (mt) genome of Lepinotus sp. The mt genome of Lepinotus sp. is 16,299 bp in size with 74.4% A + T content. The gene order was highly conserved in some of the Trogimorpha barklice. Two types of tandem repeat units were identified in CR of Lepinotus sp. The phylogenetic analysis showed that Trogiidae species was the sister group to Lepidopsocidae barklice, and the suborder Troctomorpha was polyphyletic.

Comparative mitochondrial genomics of five Dermestid beetles (Coleoptera: Dermestidae) and its implications for phylogeny

Dermestid beetles (Coleoptera: Dermestidae) are important pests of various stored products, posing potential threats to international trade. Their detailed characterization on molecular basis is a pre-requisite for proper identification and for understanding of their phylogenetic relationships. In this work, the whole mitochondrial genomes (mitogenomes) of Trogoderma granarium, Dermestes lardarius, D. ater, Attagenus augustatus augustatus and Attagenus unicolor japonicus were firstly sequenced to update the database using the next-generation sequencing technique. Based on the selected model species, a comparative analysis of four Dermestidae genera was performed. The mitochondrial genomes of these five species above showed high similarity in nucleotide composition, base composition and gene order, including 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs) and a non-coding control region, which was similar to most of Coleoptera species. The phylogenetic analysis based on the PCGs and two rRNAs indicated that the relationships within Dermestidae were reconstructed as (((Trogoderma + Anthrenus) + Attagenus) + Dermestes) using both Maximum Likelihood (ML) and Bayesian Inference (BI) analysis. However, more mitogenomes should be sequenced to obtain a more holistic view of the whole family. This study not only showed the mitogenomes of five Dermestidae species and their high conservativeness, but also discussed its implications for reconstructing a more comprehensive phylogeny of dermestids.