Pygmy grasshoppers of the genus Xistra Bolvar, 1887 (Orthoptera: Tetrigidae: Metrodorinae).

The genus Xistra Bolvar is reviewed. Two new species from China, Xistra hainanensis Deng, sp. nov. and Xistra nigriabdominis Deng, sp. nov. are described and illustrated. Three new combinations are established: Xistra emeiensis (Zheng, 1998), comb. nov., Xistra guangxiensis (Zheng, 1998), comb. nov. and Xistra lochengensis (Zheng, 2005), comb. nov. Four new synonyms are established: Bannatettix ruiliensis Zheng, 1993 = Xistra klinnema Zheng Zeng, 2011, syn. nov., Systolederus emeiensis Zheng, 1998 = Xistra yaanensis Zheng, 2009, syn. nov., Systolederus guangxiensis Zheng, 1998 = Xistra longzhouensis Zheng Jiang, 1998, syn. nov., Mazarredia lochengensis Zheng, 2005 = Xistra oculata Li, Deng Zheng, 2014, syn. nov. In addition, an updated key to all species of the genus Xistra is given.

The complete chloroplast genome of Saussurella borneensis (Orthoptera: Tetrigoidea) from China and its phylogenetic analysis.

The mitochondrial genome (mitogenome) of Saussurella borneensis (Orthoptera: Tetrigoidea) was determined and analyzed. The complete mitochondrial genome is 16,006 bp in length, consisting of 37 genes, including 13 protein-coding (PCGs), 22 tRNA, 2 rRNA genes as well as an A + T-rich region. Ten PCGs initiated with a typical ATN codon (one with ATC, two with ATA, two with ATT, and five with ATG) and 13 terminated with complete stop codons. The overall nucleotide composition was 42.97% for A, 17.61% for C, 11.62% for G, and 27.8% for T. Phylogenetic analysis of S. borneensis fully resolved it in a basal branch sister to Tripetaloceroides tonkinensis. This data increase the bioinformatics of the Tetrigidae, and improves our understanding of the phylogenetic status of S. borneensis in the Tetrigoidea.

Characterization of the complete mitochondrial genome of Tripetaloceroides tonkinensis (Orthoptera: Tetrigoidea) from China and its phylogenetic analysis.

The mitochondrial genome (mitogenome) of the Tripetaloceroides tonkinensis (Orthoptera: Tetrigoidea) was sequenced and annotated. The complete mitogenome has a length of 16,696 bp and consists of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a A + T-rich region. Thirteen PCGs started with typical ATN codon and ended with complete stop codons (five with TAG, eight with TAA). The overall nucleotide composition was 42.7% of A, 10.34% of G, 25.87% of T, and 21.08% of C. The phylogenetic trees in the current study confirmed that T. tonkinensis was clustered with other Tetrigoidea species, and the study would improve our understanding for the mitogenomes of Tetrigoidea.

Molecular data provide new insights into the phylogeny of Cladonotinae (Orthoptera: Tetrigoidea) from China with the description of a new genus and species.

Considerable effort has been devoted to elucidating the phylogenetic relationships of tetrigides. However, there is still no commonly accepted phylogenetic hypothesis. Therefore, the phylogenetic relationships among some subfamilies remain unclear; e.g., Cladonotinae is a controversial group, in which the phylogenetic relationships between genera and the boundaries of some of the included genera are unclear, causing some of the taxa to be difficult to identify. Therefore, an in-depth phylogenetic analysis of Cladonotinae is urgently needed. In this study, a robust phylogenetic framework for the tetrigides was reconstructed based on the combined mitochondrial cytochrome oxidase subunit I (COI), 16S ribosomal RNA (16S rRNA), and nuclear 18S ribosomal RNA (18S rRNA) gene sequences of 25 species belonging to 16 genera of Tetrigoidea from China, which included 13 species from 8 genera of Cladonotinae. Phylogenetic inferences were performed using the combined dataset and Bayesian inference (BI) and Maximum Parsimony (MP) methods, and the phylogenetic tree of Cladonotinae was reconstructed. All inferences based on the results of the present study supported the Cladonotinae subfamily as a polyphyletic group; within the Cladonotinae subfamily, Tetradinodula, and Tuberfemurus were closely related to Tetriginae, while Austrohancockia and Gibbotettix showed a close relationship to the Scelimenidae subfamily. Additionally, a new genus and new species of the Cladonotinae subfamily are described and illustrated: Hainantettix Deng, gen. nov. and Hainantettix strictivertex Deng, sp. nov.

New species and new synonyms of Macromotettixoides (Orthoptera: Tetrigidae) with an updated key.

The genus Macromotettixoides Zheng, Wei Jiang, 2005 is reviewed. Four new species of the genus, M. daiyunshanensis Deng, sp. nov., M. curvicarina Deng, sp. nov., M. convexa Deng, sp. nov. and M. shengtangshanensis Deng, sp. nov. are described with detailed illustrations of external morphology. Two new synonyms are established: M. jinggangshanensis, syn. nov. is synonymized with M. jiuwanshanensis Zheng, Wei Jiang, 2005; M. parvula Zha Wen, 2017, syn. nov. is synonymized with M. undulatifemura Deng, Zheng Yang, 2012. Additionally, an updated key to species of the genus is given.

Characterization of the complete mitochondrial genome of Ergatettix serrifemora (Orthoptera: Tetrigidae) from China and its phylogenetic analysis.

The mitochondrial genome (mitogenome) of the Ergatettix serrifemora (Orthoptera: Tetrigidae: Tetriginae) was sequenced and annotated. The assembled mitochondrial genome was 14,947 bp, containing 45.8% of A, 15.7% of C, 9.6% of G and 28.9% of T, respectively, which is the classical structure for insect mitogenome. The region that we failed to sequence was between rrnS and trnI, and generally contained a putative AT-rich region. Twelve PCGs started with typical ATN codon and eleven ended with complete stop codons (three with TAG, eight with TAA). The phylogenetic trees in the current study confirmed that E. serrifemora was clustered with other Tetriginae species, and this study would improve our understanding for the mitogenomes of Tetrigoidea.

The genes expression difference between winged and wingless bird cherry-oat aphid Rhopalosiphum padi based on transcriptomic data.

Aphids produce wing and wingless morphs, depending on the environmental conditions during their complex life cycles. Wing and wingless variations play an important role in migration and host alternation, affecting the migration and host alternation processes. Several transcriptional studies have concentrated on aphids and sought to determine how an organism perceives environmental cues and responds in a plastic manner, but the underlying mechanisms have remained unclear. Therefore, to better understand the molecular mechanisms underlying the wing polyphenism of this fascinating phenomenon, we provide the first report concerning the wing development of aphids in bird cherry-oat aphid Rhopalosiphum padi with comparative transcriptional analysis of all the developmental stages by RNA-Seq. We identified several candidate genes related to biogenic amines and hormones that may be specifically involved in wing development. Moreover, we found that the third instar stage might be a critical stage for visibility of alternative morphs as well as changes in the expression of thirty-three genes associated with wing development. Several genes, i.e., Wnt2, Fng, Uba1, Hh, Foxo, Dpp, Brk, Ap, Dll, Hth, Tsh, Nub, Scr, Antp, Ubx, Asc, Srf and Fl, had different expression levels in different developmental stages and may play important roles in regulating wing polyphenism.