Mitochondrial genome data provide insights into the phylogenetic relationships within Triplophysadalaica (Kessler, 1876) (Cypriniformes, Nemacheilidae).

Due to the detrimental effect of formaldehyde on DNA, ethanol has replaced formalin as the primary preservative for animal specimens. However, short-term formalin fixation of specimens might be applied during field collection. In an increasing number of studies, DNA extraction and sequencing have been successfully conducted from formalin-fixed specimens. Here the DNA from five specimens of Triplophysadalaica (Kessler, 1876) were extracted and performed high-throughput sequencing. Four of the specimens underwent short-term fixation with formalin and were subsequently transferred to ethanol. One was continuously stored in ethanol. No significant difference of DNA quality and amount were observed among these samples. Followed by assembly and annotation, five mitochondrial genomes ranging in length from 16,569 to 16,572 bp were obtained. Additionally, previously published data of other individuals or species were included to perform phylogenetic analyses. In the reconstructed trees, all eight individuals of T.dalaica form a monophyletic group within the Triplophysa branch. The group is divided into three clades: (1) samples from the Yellow River, (2) those from the Yangtze River, and (3) those from the Haihe River, and the Lake Dali Nur. This study sheds initial light on the phylogeographic relationships among different populations of T.dalaica, and will support the research about its evolutionary history in the future.

Two new species of Sinolachnus Hille Ris Lambers (Hemiptera, Aphididae, Lachninae) from China.

Two new Sinolachnus species from China, Sinolachnusrubusis Qiao & Li, sp. nov. feeding on Rubus sp. from Shaanxi and Sichuan Provinces, and Sinolachnusyunnanensis Qiao & Li, sp. nov. feeding on Elaeagnus sp. from Yunnan Province, are described and illustrated. Keys to Sinolachnus species distributed in China are presented. All examined specimens are deposited in the National Zoological Museum of China, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.

Cavariella Del Guercio (Hemiptera, Aphidinae, Macrosiphini) in China, with a new species, new synonymies, and first country records.

The genus Cavariella is distinguished from other Macrosiphini genera (Aphididae, Aphidinae) because it has a supra-caudal process on abdominal tergite VIII which possesses two setae distally. It is Holarctic in distribution, and half of its species are Asian. The Chinese fauna of this genus, 17 species, have been restudied, morphologically and through DNA barcodes. As a result: Cavariellahidaensis Takahashi is transferred to Elatobium; Cavariellasculptura Qiao & Xu, sp. nov. is described from specimens collected on Torilis and Cryptotaenia (Apiaceae); Cavariellacessana Zhang, Chen, Zhong & Li, syn. nov. and Cavariellalargispiracula Zhang, Chen, Zhong & Li, syn. nov. are respectively junior synonyms of Cavariellaaquatica (Gillette & Bragg) and Cavariellasapporoensis Takahashi; Cavariellagilgiana Zhang, Chen, Zhong & Li and Cavariellalhasana Zhang are confirmed as valid species and complete descriptions are provided; Cavariellabhutanensis Chakrabarti & Das, Cavariellanigra Basu, Cavariellapastinacae (Linnaeus), and Cavariellapustula Essig are recorded for the first time from China. Additionally, keys for species of Cavariella known in China are provided and modifications to the key by Blackman and Eastop of aphid species on Angelica (Aphids on World's Plants) are presented.

Revision of the genus Allocotaphis Börner, 1950 (Hemiptera, Homoptera, Aphididae, Macrosiphini).

Allocotaphis Börner, 1950 (Hemiptera, Homoptera, Aphididae, Aphidinae, Macrosiphini) and its three species are fully revised. The history of the descriptions of the involved taxa is critically presented. Descriptions of the known morphs of these species and complete information on the biology and distribution of the species are presented. Three subjective synonymies are established: Spinaphis L.K. Ghosh, 1986 syn. n. and Longisiphoniella Chakrabarti, Saha & Mandal, 1988 syn. n. of Allocotaphis Börner, 1950, and Longisiphoniella subterranea Chakrabarti, Saha & Mandal, 1988 syn. n. of Allocotaphis multisetosa (L.K. Ghosh, 1986) comb. n. An hypothesis for the formation of the genus and the speciation that took place within it is proposed.

A new species of Eulachnus Del Guercio from China (Hemiptera: Aphididae: Lachninae).

We describe apterous and alate viviparous females of a new species of the Lachninae genus Eulachnus (Eulachnini) from China. The new species, Eulachnus blackmani sp. nov., can be easily separated from other Asian representatives of this genus: the ultimate rostral segments are without accessory setae; the spinal scleroites are larger than the pleural and marginal ones; there are a few very long setae on the distal part of the tibiae and on the hind tarsus. The new species is morphologically most similar to the European E. nigricola (Paek), and hence unusual within the Asian Eulachnus fauna.

Six new species of Aspidophorodon Verma, 1967 (Hemiptera, Aphididae, Aphidinae) from China.

The genus Aspidophorodon Verma is presented including six new species from China namely Aspidophorodoncapitatum Qiao & Xu, sp. nov. Aspidophorodonlongicornutum Qiao & Xu, sp. nov. Aspidophorodonreticulatum Qiao & Xu, sp. nov. Aspidophorodonfurcatum Qiao & Xu, sp. nov. Aspidophorodonlongirostre Qiao & Xu, sp. nov. and Aspidophorodonobtusirostre Qiao & Xu, sp. nov. Aspidophorodoncornuatum Qiao 2015, is considered as a junior synonym of Aspidophorodonlongituberculatum (Zhang Zhong & Zhang 1992), syn. nov. Two species Aspidophorodonharvense Verma and Aspidophorodonindicum (David Rajasingh & Narayanan) are recorded for the first time in China. The genus is mainly distributed in East Asia and is represented by 15 species in the world of which 12 are found in China. Keys to the species of Aspidophorodon are given.

Studies on the genus Psephenothrips Reyes from China (Thysanoptera, Phlaeothripinae), with one new species.

Species from China of the Asian genus Psephenothrips are reviewed, with P. eriobotryae sp. nov. collected from the leaves of Eriobotrya japonica in Sichuan Province. A key to the five species known from China is provided and the COI sequence of the new species is also given.

Diversity of bacteria associated with Hormaphidinae aphids (Hemiptera: Aphididae).

Bacteria are ubiquitous inhabitants of animals. Hormaphidinae is a particular aphid group exhibiting very diverse life history traits. However, the microbiota in this group is poorly known. In the present study, using high-throughput sequencing of bacterial 16S ribosomal RNA gene amplicons, we surveyed the bacterial flora in hormaphidine aphids and explored whether the aphid tribe, host plant and geographical distribution are associated with the distribution of secondary symbionts. The most dominant bacteria detected in hormaphidine species are heritable symbionts. As expected, the primary endosymbiont Buchnera aphidicola is the most abundant symbiont across all species and has cospeciated with its host aphids. Six secondary symbionts were detected in Hormaphidinae. Arsenophonus is widespread in Hormaphidinae species, suggesting the possibility of ancient acquisition of this symbiont. Ordination analyses and statistical tests show that the symbiont composition does not seem to relate to any of the aphid tribes, host plants or geographical distributions, which indicate that horizontal transfers might occur for these symbionts in Hormaphidinae. Correlation analysis exhibits negative interference between Buchnera and coexisting secondary symbionts, while the interactions between different secondary symbionts are complicated. These findings display a comprehensive picture of the microbiota in Hormaphidinae and may be helpful in understanding the symbiont diversity within a group of aphids.

 Neothelaxespileata, a new species from China (Hemiptera, Sternorrhyncha, Aphididae, Thelaxinae).

Neothelaxespileata Qiao sp. nov., found on Pileamartinii (Urticaceae) in China, is described and illustrated. Neothelaxes Chakrabarti & Quednau is also a new generic record for China.

Studies on the genus Mesandrothrips from China, with a new species (Thysanoptera: Phlaeothripinae: Haplothripini).

In the recently re-instated genus Mesandrothrips Priesner, four species are recognized from China, and an illustrated key is provided here. This includes one new species, M. acutisetis sp.n., together with the first record of M. subterraneus from China.

Host Plants Influence the Symbiont Diversity of Eriosomatinae (Hemiptera: Aphididae).

Eriosomatinae is a particular aphid group with typically heteroecious holocyclic life cycle, exhibiting strong primary host plant specialization and inducing galls on primary host plants. Aphids are frequently associated with bacterial symbionts, which can play fundamental roles in the ecology and evolution of their host aphids. However, the bacterial communities in Eriosomatinae are poorly known. In the present study, using high-throughput sequencing of the bacterial 16S ribosomal RNA gene, we surveyed the bacterial flora of eriosomatines and explored the associations between symbiont diversity and aphid relatedness, aphid host plant and geographical distribution. The microbiota of Eriosomatinae is dominated by the heritable primary endosymbiont Buchnera and several facultative symbionts. The primary endosymbiont Buchnera is expectedly the most abundant symbiont across all species. Six facultative symbionts were identified. Regiella was the most commonly identified facultative symbiont, and multiple infections of facultative symbionts were detected in the majority of the samples. Ordination analyses and statistical tests show that the symbiont community of aphids feeding on plants from the family Ulmaceae were distinguishable from aphids feeding on other host plants. Species in Eriosomatinae feeding on different plants are likely to carry different symbiont compositions. The symbiont distributions seem to be not related to taxonomic distance and geographical distance. Our findings suggest that host plants can affect symbiont maintenance, and will improve our understanding of the interactions between aphids, their symbionts and ecological conditions.

Review of Mesocallis Matsumura from China (Hemiptera, Aphididae), with one new species.

The aphid genus Mesocallis Matsumura in China is reviewed. A total of seven species are recognised using morphological characteristics, including six known species, Mesocallis (Mesocallis) alnicola Ghosh, M. (Paratinocallis) corylicola (Higuchi), M. (M.) pteleae Matsumura, M. (M.) sawashibae (Matsumura), M. (P.) yunnanensis (Zhang) and M. (M.) taoi Quednau, and one new species, M. (M.) platycaryae Qiao, sp. nov. The new species, collected on Platycarya strobilacea (Juglandaceae) in Anhui Province, China, is described and illustrated. A key to Mesocallis species from China is presented.

The evolution of climate tolerance in conifer-feeding aphids in relation to their host's climatic niche.

Climate adaptation has major consequences in the evolution and ecology of all living organisms. Though phytophagous insects are an important component of Earth's biodiversity, there are few studies investigating the evolution of their climatic preferences. This lack of research is probably because their evolutionary ecology is thought to be primarily driven by their interactions with their host plants. Here, we use a robust phylogenetic framework and species-level distribution data for the conifer-feeding aphid genus Cinara to investigate the role of climatic adaptation in the diversity and distribution patterns of these host-specialized insects. Insect climate niches were reconstructed at a macroevolutionary scale, highlighting that climate niche tolerance is evolutionarily labile, with closely related species exhibiting strong climatic disparities. This result may suggest repeated climate niche differentiation during the evolutionary diversification of Cinara. Alternatively, it may merely reflect the use of host plants that occur in disparate climatic zones, and thus, in reality the aphid species' fundamental climate niches may actually be similar but broad. Comparisons of the aphids' current climate niches with those of their hosts show that most Cinara species occupy the full range of the climatic tolerance exhibited by their set of host plants, corroborating the hypothesis that the observed disparity in Cinara species' climate niches can simply mirror that of their hosts. However, 29% of the studied species only occupy a subset of their hosts' climatic zone, suggesting that some aphid species do indeed have their own climatic limitations. Our results suggest that in host-specialized phytophagous insects, host associations cannot always adequately describe insect niches and abiotic factors must be taken into account.

Review of Podothrips from China (Thysanoptera, Phlaeothripidae), with one new species and three new records.

Podothrips species occur on the leaves of various Poaceae, including bamboo and grasses. An illustrated identification key is given here to the six Podothrips species recorded from China. These include P. femoralis Dang & Qiao, sp. nov., and P. sasacola Kurosawa, P. odonaspicola (Kurosawa), and P. semiflavus Hood that are newly recorded from China.

Wolbachia Infection in Two Species: Novel Views on the Colonization Ability of Wolbachia in Aphids.

Wolbachia pipientis (Rickettsiales: Anaplasmataceae) is an intracellular symbiont residing in arthropods and filarial nematodes. Sixteen supergroups have been described from different host taxa. Four supergroups A, B, M, and N were found in aphids according to prior studies. The cotton aphid, Aphis gossypii, and the green peach aphid, Myzus persicae, are typical polyphagous species with global distributions. We conducted an extensive and systematic survey of Wolbachia infections in these aphids from China. High incidences of Wolbachia infection were detected. The total infection incidence was 60% in A. gossypii and 88% in M. persicae. Both aphid species were infected with supergroups A, B and M. Different incidences of infection were observed among the seven geographical regions in China, which suggested a positive relationship between Wolbachia infections and the geographical distribution of aphid species. Furthermore, multiple infection patterns (M, B, A&M, B&M, and A&B&M) were observed. Infection patterns M and B&M were detected in almost all populations. Patterns A&B&M and B showed geographical restriction in North China. Three factors can possibly influence the Wolbachia infection incidences and patterns: the geographical distribution, aphid species, and different supergroup types.

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.

The mitochondrial genome of Greenidea psidii van der Goot (Hemiptera: Aphididae: Greenideinae) and comparisons with other Aphididae aphids.

The complete mitochondrial genome of Greenidea psidii was sequenced and compared with the genomes of other aphid species. The G. psidii mitogenome is 16,202 bp long with an A + T content of 85.4%, comprising 37 genes arranged in the same order as the inferred insect ancestral arrangement, a control region and a special repeat region between trnE and trnF. G. psidii is the first representative possessing such a repeat region from the subfamily Greenideinae. These repeat motifs found in Aphidinae, Eriosomatinae and Greenideinae are species-specific, differing in nucleotide composition, length and copy number across different species. All reported complete aphid mitogenomes are A- and C-skewed in the whole genomes and show opposite skewness for C and G between the majority and minority strands. The ratios of nonsynonymous to synonymous substitution rates indicated that the evolution of the aphid mitogenomes has been dominated by purifying selection. Based on whole mitogenome sequences, the phylogenetic relationships among all aphid species with complete mitogenomes were investigated. G. psidii was robustly clustered with Cervaphis quercus, confirming its affiliation with the subfamily Greenideinae.

Insect-bacteria parallel evolution in multiple-co-obligate-aphid association: a case in Lachninae (Hemiptera: Aphididae).

Parallel phylogenies between aphid and its obligate symbiont Buchnera are hot topics which always focused on aphid lower taxonomic levels. Symbionts in the subfamily Lachninae are special. Buchnera in many lachnine species has undergone functional and genome size reduction that was replaced by other co-obligate symbionts. In this study, we constructed the phylogenetic relationships of Lachninae with a combined dataset of five genes sequenced from Buchnera to estimate the effects of a dual symbiotic system in the aphid-Buchnera cospeciation association. The phylogeny of Buchnera in Lachninae was well-resolved in the combined dataset. Each of the genera formed strongly supported monophyletic groups, with the exception of the genus Cinara. The phylogeny based on sequences from Buchnera was divided into five tribes according to the clades of the Lachninae hosts tree, with the phylogenies of Buchnera and Lachninae being generally congruent. These results first provided evidence of parallel evolution at the aphid subfamily level comprehensively and supported the view that topological congruence between the phylogenies of Buchnera and Lachninae would not be interfered with the other co-obligate symbionts, such as Sarretia, in aphid-entosymbiont association. These results also provided new insight in understanding host-plant coevolution in lachnine lineages.

EF-1α DNA Sequences Indicate Multiple Origins of Introduced Populations of Essigella californica (Hemiptera: Aphididae).

Aphids in the pine-feeding Nearctic genus Essigella (Sternorrhyncha, Aphididae, Lachninae) have been introduced in Europe, North Africa, Oceania, and South America. Mitochondrial, nuclear, and endosymbiont DNA sequences of 12 introduced populations from three continents confirm they all belong to Essigella californica (Essig, 1909). Intron sequence variation of the nuclear gene EF-1α has revealed the existence of four distinct groups. Group I gathers one population from China, where the species is newly reported, and several from Europe (France and Italy); Group II is represented by one population from Argentina; Group III includes two populations from Southern Australia with one from New Zealand; and Group IV corresponds to five populations from Eastern and South-Eastern Australia. These results indicate that introduced populations of E. californica have at least four source populations. They also show that intron variation of EF-1α can be a method to discriminate populations of asexually reproducing aphids.

DNA barcoding and species delimitation of Chaitophorinae (Hemiptera, Aphididae).

Chaitophorinae aphids are widespread across Eurasia and North America, and include some important agricultural and horticultural pests. So, accurate rapid species identification is very important. Here, we used three mitochondrial genes and one endosymbiont gene to calculate and analyze the genetic distances within different datasets. For species delimitation, two distance-based methods were employed, threshold with NJ (neighbor-joining) and ABGD (Automatic Barcode Gap Discovery), and two tree-based approaches, GMYC (General Mixed Yule Coalescent) and PTP (Poisson Tree Process). The genetic interspecific divergence was clearly larger than the intraspecific divergence for four molecular markers. COI and COII genes were found to be more suitable for Chaitophorinae DNA barcoding. For species delimitation, at least one distance-based method combined with one tree-based method would be preferable. Based on the data for Chaitophorus saliniger and Laingia psammae, DNA barcoding may also reveal geographical variation.