The complete mitochondrial genome of Neuroctenus taiwanicus (Hemiptera: Aradidae).

Neuroctenus taiwanicus Kormilev, 1955 is a flat-bodied and enigmatic bug that was first discovered on the island of Taiwan, China. In this study, the whole mitochondrial genome of N. taiwanicus was sequenced and annotated for the first time, and its genomic data were uploaded to Genbank feedback number OR675057. The mitochondrial genome of N. taiwanicus is 15,340 bp in length, a typical circular DNA encoding 37 genes and a control region with 68.4% A + T content. The phylogeny reveals the taxonomic status of N. taiwanicus, which is most closely related to N. yunnanensis, and demonstrates the sister relationship among Neuroctenus, Mezira, and Brachyrhynchus. In addition, the results also confirm that Aradinae and Calisiinae are the earliest branching and more primitive in the family Aradidae, which is consistent with the analysis of the traditional classification.

Complete mitochondrial genome of Neuroctenus yunnanensis Hsiao, 1964 (Hemiptera: Aradidae: Mezirinae).

The complete Neuroctenus yunnanensis Hsiao, 1964, mitogenome was sequenced using an Illumina NovaSeq platform and submitted to GenBank (accession number: ON507991). The mitochondrial genome is a typical circular DNA molecule of 15,283 bp with 37 genes, including 22 tRNA genes, 13 protein-coding genes (PCGs), two rRNA genes, and a control region. Phylogenetic reconstruction validated the taxonomic status of N. yunnanensis, which was placed in the Mezirinae subfamily (Aradidae) and most closely related to N. parus. The mitochondrial genome data of N. yunnanensis provides a basis for genetic research.

Leucobacter tenebrionis sp. nov., isolated from the gut of Tenebrio molitor.

A novel Gram-stain-positive bacterium, designated NB10T, was isolated from the gut of Tenebrio molitor. The isolate was rod-shaped, aerobic, non-motile and non-spore-forming. Colonies of strain NB10T were light yellow, circular and smooth. Phylogenetic analysis based on 16S rRNA gene sequence comparisons indicated that the isolate was related to the genus Leucobacter. Its closest relatives were Leucobacter holotrichiae T14T (97.8 % 16S rRNA gene sequence similarity), Leucobacter zeae CC-MF41T (97.0%) and Leucobacter salsicius M1-8T (96.4%). The DNA G+C content of strain NB10T was 68.8 mol%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization values among strain NB10T and the selected Leucobacter species were ≤83.8 % (ANI-blast), 87.6 % (ANI-MUMmer) and 29.6%, which were below the recommended cutoff values for species delineation. The predominant cellular fatty acids were anteiso-C15 : 0 (39.0%), anteiso-C17 : 0 (35.5%) and iso-C16 : 0 (17.0%). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and glycolipids. The predominant respiratory quinones were MK-11 and MK-10. The cell wall amino acids were Gly, Glu, Tr, Ala, and DAB. Based on these phylogenetic and phenotypic results, strain NB10T can be clearly distinguished from all of the recognized species of the genus Leucobacter and is considered to represent a novel species of that genus. The name Leucobacter tenebrionis sp. nov. is proposed, with the type strain NB10T (=MCCC 1K07072T=KCTC 49728T).

The complete mitochondrial genome of Brachyrhynchus triangulus (Hemiptera: Aradoidea: Aradidae).

The complete mitochondrial genome of Brachyrhynchus triangulus Bergroth, 1889 was sequenced and annotated in the present study. It was a typical circular DNA molecule of 15,170 bp, with 37 genes and a control region. The percentages of A, C, G, and T nucleotides in the genome of B. triangulus were 41.1%, 17.4%, 11.9%, and 29.4%, respectively. Thirteen protein-coding genes (PCGs) start with a ATN codon or a TTG codon and terminate with a TAA codon or a TAG codon or a single T residue. With the exception of tRNASer(AGN) , each of the 22 tRNA genes had a clover-leaf structure and ranged in length from 62 to 69 bp. The length of lrRNA and srRNA was 1241 bp and 828 bp, respectively. The control region had a length of 708 bp and an A + T content of 74.6%. The sister relationship between B. triangulus and Brachyrhynchus hsiaoi is supported by the phylogenetic tree. Additionally, it proved the sister relationship between Mezirinae and Aneurinae, supporting the classical taxonomy of the Aradidae.

Scanning Electron Microscopy of Antennae and Mouthparts of Mezira yunnana Hsiao (Hemiptera: Aradidae): Specialized Microstructures Reflecting Adaptation to Mycetophagy.

Many species of the family Aradidae (also known as flat bugs) feed on fungal mycelia and fruiting bodies. In order to better understand the morphological adaptation to this unique feeding habit, we examined the microstructure of antennae and mouthparts of an aradid species, Mezira yunnana Hsiao, using scanning electron microscope, and documented the fungal feeding process under laboratory conditions. The antennal sensilla include three subtypes of sensilla trichodea, three subtypes of sensilla basiconica, two subtypes of sensilla chaetica, sensilla campaniformia, and sensilla styloconica. The apex of the second segment of flagellum has a large number of various sensilla forming a sensilla cluster. The labial tip is distally constricted, which is rarely observed in other Pentatomomorpha species. The labial sensilla include three subtypes of sensilla trichodea, three subtypes of sensilla basiconica, and a sensilla campaniformia. The tip of the labium has only three pairs of sensilla basiconica III and small comb-shaped cuticular processes. The external surface of the mandibular apex has 8-10 ridge-like central teeth. A series of key morphological structures associated with mycetophagous feeding habit were identified, which will facilitate future studies on adaptive evolution of species in Pentatomomorpha as well as in other heteropteran lineages.

Paracremastaptera, a new apterous genus of Mezirinae from China (Hemiptera: Aradidae).

A new apterous flat bug genus and species, Paracremastaptera ximaensis Bai, Heiss Cai, gen. nov. and sp. nov., is described from Yunnan, China. The diagnostic morphological features of the new genus and species are illustrated.

A new apterous genus of Carventinae from Hainan, China (Hemiptera: Heteroptera: Aradidae).

A new apterous genus and species of flat bugs, Neolibiocoris obtusus gen. nov. and sp. nov., and an additional new species, Rotundocoris pyramidalis sp. nov. (Hemiptera: Heteroptera: Aradidae: Carventinae), are described from Hainan Island, China. The diagnostic morphological features of the new genus and species are discussed and illustrated. A revised key to apterous genera of Carventinae from Hainan Island is presented.

A new apterous genus of Carventinae from China (Hemiptera: Heteroptera: Aradidae).

A new apterous genus and species, Oblongocoris hainanensis gen. and sp. nov. (Hemiptera: Heteroptera: Aradidae: Carventinae), are described from Hainan, China. The diagnostic morphological features of the new genus and species are discussed and illustrated, and a key to genera of Carventinae from Hainan Island is presented.

Rotundocoris, a new apterous genus of Carventinae from China (Heteroptera: Aradidae).

A new apterous genus, Rotundocoris gen. nov., and two included new species, R. stenonotum sp. nov. and R. obliquonotum sp. nov. (Hemiptera: Heteroptera: Aradidae: Carventinae), are described from Hainan, China. The diagnostic morphological features of the genus and its two species are discussed and illustrated.

Neocrassocoris, a new apterous genus of Carventinae from China (Heteroptera: Aradidae).

A new apterous genus, Neocrassocoris gen. nov., with two new species, N. pingbianensis sp. nov. and N. longzhouensis sp. nov. (Heteroptera: Aradidae: Carventinae), are described from Yunnan and Guangxi Provinces of China. The diagnostic morphological features of both taxa are described and illustrated.

The Oriental flat bug genus Libiocoris Kormilev, 1957 revisited: re-examination, synonymy, and description of a new genus (Heteroptera, Aradidae).

Re-examination of type specimens of LibiocorisKormilev 1957, L.poecilus from New Guinea and other taxa assigned to this genus, the Chinese Libiocorisheissi Bai, Yang & Cai, 2006 and Libiocorissinensis Bai, Yang & Cai, 2006 proved to be synonyms, thus L.heissi = L.sinensis syn. n. They are, however, different from Libiocoris Kormilev, 1957 to which they were originally assigned and a new genus Paralibiocoris gen. n. is proposed for them. Therefore Paralibiocorisheissi comb. n. = Libiocorisheissi Bai et al., 2006 = Libiocorissinensis Bai et al., 2006, syn. n. From Hainan Island, China, the following new species, P.roundangulus sp. n., P.hainanensis sp. n., and P.limuensis sp. n., are described and figured and a key to species is provided.

Aradidae from Vietnam V. Bifurcatoaptera, a new genus of apterous Carventinae (Hemiptera: Heteroptera: Aradidae) from Vietnam.

A new apterous genus and species of Aradidae (Hemiptera: Heteroptera), Bifurcatoaptera lamdongensis gen. et sp. nov., is described from Vietnam. The diagnostic morphological features of the new species are described and illustrated.

Reconsideration of the apterous carventine genus Crassocoris and description of Paracrassocoris gen. nov. from China (Hemiptera: Heteroptera: Aradidae).

Based on new topotypical material, the apterous carventine genus Crassocoris Bai, Heiss Cai, 2007 (Hemiptera: Heteroptera: Aradidae) with the type species C. hsiaoi Bai, Heiss Cai, 2007, is redescribed. A new, closely related apterous genus and species, Paracrassocoris hekouensis gen. nov., sp. nov. is described from Hainan, China. The diagnostic morphological features of both taxa are described and illustrated.

Pseudowuiessa, a new genus of brachypterous Mezirinae (Hemiptera: Heteroptera: Aradidae) from China.

A new brachypterous flat bug (Hemiptera: Heteroptera: Aradidae) genus and species, Pseudowuiessa producta Bai, Heiss & Cai, gen. nov. & sp. nov., is described from Yunnan, China. A key to related genera is given and the diagnostic characters of the new taxon are illustrated.

Rearrangement of mitochondrial tRNA genes in flat bugs (Hemiptera: Aradidae).

The typical insect mitochondrial (mt) genome organization, which contains a single chromosome with 37 genes, was found in the infraorder Pentatomomorpha (suborder Heteroptera). The arrangement of mt genes in these true bugs is usually the same as the ancestral mt gene arrangement of insects. Rearrangement of transfer RNA (tRNA) genes, however, has been found in two subfamilies of flat bugs (Mezirinae and Calisiinae, family Aradidae). In this study, we sequenced the complete mt genomes of four species from three other subfamilies (Aradinae, Carventinae and Aneurinae). We found tRNA gene rearrangement in all of these four species. All of the rearranged tRNA genes are located between the mitochondrial control region and cox1, indicating this region as a hotspot for gene rearrangement in flat bugs; the rearrangement is likely caused by events of tandem duplication and random deletion of genes. Furthermore, our phylogenetic and dating analyses indicated that the swap of positions between trnQ and trnI occurred ~162 million years ago (MYA) in the most recent common ancestor of the five subfamilies of flat bugs investigated to date, whereas the swap of positions between trnC and trnW occurred later in the lineage leading to Calisiinae, and the translocation of trnC and trnY occurred later than 134 MYA in the lineage leading to Aradinae.

A new apterous genus of Carventinae (Hemiptera: Aradidae) from China.

A new apterous aradid, Paramorphocoris henanensis Bai & Heiss Cai, gen. et sp. nov., from China is described and illustrated, including the diagnostic morphological features of the new taxon.

Aradidae from Vietnam IV. Review of the Oriental flat bug genus Lissonotocoris Usinger & Matsuda, 1959 (Hemiptera: Heteroptera: Aradidae).

To date, only the type species Lissonotocoris membranaceus Usinger & Matsuda 1959 is known and recorded from Vietnam and China, Hainan Island. Four new species of the previously monotypic genus Lissonotocoris are described and figured: loebli n.sp. (Thailand), glabronotus n.sp. (N.Vietnam), pachycerus n.sp. (Malaysia) and siamensis n.sp. (Thailand). A key for the identification of all 5 species is provided.

Aradidae from Vietnam III. Trichosomaptera gibbosa n.gen., n.sp., an apterous Carventinae (Hemiptera: Heteroptera: Aradidae) .

A new apterous flat bug genus of the subfamily Carventinae, Trichosomaptera n.gen., is described and illustrated to accommodate gibbosa n. sp. from Vietnam. The species could not be placed in any known genus.

Aradidae from Vietnam II. Longitergus, a new genus and two new species of micropterous Mezirinae (Hemiptera: Heteroptera: Aradidae).

A new micropterous flat bug genus, Longitergus n.gen. with the species productus n.sp. and similis n.sp. from Vietnam, is described. A key to related Oriental genera is given and the diagnostic morphological characters of the new genus and species are illustrated.