Contribution to the mitogenome diversity in Delphacinae: Phylogenetic and ecological implications.

We document the complete (or nearly complete) mitogenomes of 20 Delphacidae taxa, and together with 17 other delphacid mitogenomes currently in GenBank, to reconstruct the phylogeny of the Delphacinae and to investigate mitogenome differences among members of Delphacini, Tropidocephalini and Saccharosydnini. The mitogenomes of the 20 species encode the complete set of 37 genes usually found in animal mitogenomes. The length of complete mitogenomes in Delphacinae ranges from 15,531 to 16,231 bp. The gene order of all newly sequenced mitogenomes are identical, and the mitogenome gene order of Stenocranus matsumurai Metcalf in Stenocraninae has a transposition of tRNAThr. The two-clade system in Tropidocephalini was supported with high value (PP = 1, BS = 100), and the monophyly of Bambusiphaga was recovered in this study. Finally, we found that the host shift from plants with a C3 to a C4 photosynthetic pathway appears to have occurred independently in several clades.

Characterization of Three Complete Mitogenomes of Flatidae (Hemiptera: Fulgoroidea) and Compositional Heterogeneity Analysis in the Planthoppers' Mitochondrial Phylogenomics.

Although sequences of mitogenomes have been widely used for investigating phylogenetic relationship, population genetics, and biogeography in many members of Fulgoroidea, only one complete mitogenome of a member of Flatidae has been sequenced. Here, the complete mitogenomes of Cerynia lineola, Cromna sinensis, and Zecheuna tonkinensis are sequenced. The gene arrangements of the three new mitogenomes are consistent with ancestral insect mitogenomes. The strategy of using mitogenomes in phylogenetics remains in dispute due to the heterogeneity in base composition and the possible variation in evolutionary rates. In this study, we found compositional heterogeneity and variable evolutionary rates among planthopper mitogenomes. Phylogenetic analysis based on site-homogeneous models showed that the families (Delphacidae and Derbidae) with high values of Ka/Ks and A + T content tended to fall together at a basal position on the trees. Using a site-heterogeneous mixture CAT + GTR model implemented in PhyloBayes yielded almost the same topology. Our results recovered the monophyly of Fulgoroidea. In this study, we apply the heterogeneous mixture model to the planthoppers' phylogenetic analysis for the first time. Our study is based on a large sample and provides a methodological reference for future phylogenetic studies of Fulgoroidea.

Microsatellite markers from tea green leafhopper Empoasca (Matsumurasca) onukii: a powerful tool for studying genetic structure in tea plantations.

BACKGROUND: Tea green leafhopper is one of the most dominant pests in Chinese tea plantations. Recent evidence, including morphological and molecular data, revealed that tea green leafhopper in China is the same species as in Japan, Empoasca (Matsumurasca) onukii Matsuda. Previous morphological study that revealed variation in the structure of the male genitalia within and among populations of this species suggested that there may be significant population-level genetic variation. To provide powerful molecular markers to explore the population genetic diversity and population genetic structure of this pest in China, microsatellite markers were obtained by AFLP of sequences containing repeats (FIASCO). RESULTS: Eighteen polymorphic markers were evaluated for five populations of E. (M.) onukii, Two related empoascine leafhopper species were selected to test the transferability of the markers. Population genetic structure of E. (M.) onukii was detected using Structure analysis, principal coordinate analysis (PCoA) and variance analysis. The identified markers were polymorphic with total number of alleles ranging from 6 to 24 per locus, observed and expected heterozygosity ranged from 0.133 to 0.9 and 0.183 to 0.926, respectively, and the polymorphic information content value over all populations varied from 0.429 to 0.911. CONCLUSIONS: This is the first study to demonstrate that microsatellite markers provide valuable information for genetic structure of E. (M.) onukii in Chinese tea plantations. There is obvious genetic differentiation between the two populations in the Southwest tea area. These microsatellite markers will be the powerful tools for genetic studies of E. (M.) onukii and improve understanding of the microevolution of this species.

Alafrasca sticta, a new genus and species of the tribe Empoascini (Hemiptera: Cicadellidae: Typhlocybinae) with a checklist of the tribe from China.

A new monotypic genus of empoascine leafhopper, Alafrasca gen. nov. is described and illustrated for A. sticta sp. nov. from Sichuan, China as its type species. Habitus photos and illustrations of male genitalia of the new species are given. A checklist of the tribe in China is also provided.

Lauriana Ren & Qin, a new genus of the tribe Tropidocephalini (Hemiptera: Fulgoromorpha: Delphacidae) from China.

A new delphacid genus and species, Lauriana senticosa Ren & Qin, gen. et sp. nov. (Hemiptera: Delphacidae: Tropidocephalini) is described from Sichuan, China. Habitus photos and illustrations of male genitalia of the new species are given, and the differences between the new genus and its closely related genera are discussed.

A new genus of the tribe Hemisphaeriini (Hemiptera: Fulgoromorpha: Issidae) from China.

A new issid genus in the tribe Hemisphaeriini (Hemiptera: Fulgoromorpha: Issidae) is described from China: Rotundiforma gen. nov.. One new species, Rotundiforma nigrimaculata sp. nov. (China: Yunnan, Menglun), is described and illustrated. Distribution and morphological diversity of tribe Hemisphaeriini are discussed briefly. A checklist for the 14 genera of Hemisphaeriini is provided.

A key to genera of Dikraneurini from China, with description of a new species of Cornicola Ohara & Hayashi (Hemiptera, Cicadellidae, Typhlocybinae).

The leafhopper genus Cornicola Ohara & Hayashi, previously recorded from Japan, is recorded from China for the first time and a new species, C.maculatus Xu, Dietrich & Qin, sp. nov., is described and illustrated, including its color polymorphism. This genus has male genitalia and hind wing venation similar to those found in Empoascini but it is more appropriately placed in Dikraneurini. A key to species of Cornicola is given together with a key to the genera of Dikraneurini from China.

A new genus of Empoascini (Hemiptera, Cicadellidae, Typhlocybinae) from Papua New Guinea.

Ivmaka longicaudatus gen. et sp. nov. is described based on specimens from Papua New Guinea. Habitus photos and illustrations of the male genitalia of this new species are given and differences between the new genus with closely related genera are discussed.

Comparative Analysis of the Complete Mitochondrial Genomes of Five Species of Ricaniidae (Hemiptera: Fulgoromorpha) and Phylogenetic Implications.

Ricaniidae is a relatively small planthopper family with about 69 genera and 442 species worldwide. Members of this family occur throughout the warm temperate and tropical regions. Some species cause devastating damage to major agricultural and economic plants. However, the relationship between Ricaniidae and other families of Fulgoroidea needs to be further explored. The morphological definitions of the two biggest genera, Pochazia Amyot & Serville, 1843 and Ricania Germar, 1818 (the type genus of Ricaniidae) remain controversial. In this study, mitogenomes of five representatives in these two genera were decoded using the next-generation sequence method and genome assembly. Results showed that their complete mitogenomes are circular DNA molecules with 15,457 to 16,411 bp. All protein-coding genes (PCGs) begin with the start codon ATN, GTG or TTG and end with TAA, TAG, an incomplete stop codon single T or an incomplete stop codon single A. A lost DHU arm was discovered in the trnS gene of the five mitogenomes and the trnV gene within Pochaziaconfusa, Pochazia guttifera and Ricania simulans. The remnant tRNAs folded into clover-leaf structures. The sliding window, genetic distance, and Ka/Ks analyses indicated that the cox1 gene is the slowest evolving and is relatively conserved. The phylogenetic tree topologies support (Delphacidae + (((Issidae + (Lophopidae + Caliscelidae)) + (Flatidae + Ricaniidae)) + (Achilidae + (Dictyopharidae + Fulgoridae)))) as the best topology, as recognized by both PhyloBayes, RAxML and MrBayes based on four data sets (PCG, PCGRNA, PCG12, PCG12RNA). The monophyly of Ricaniidae and the sister group status of two families Flatidae and Ricaniidae are supported, but all analyses failed to support the monophyly of Pochazia and Ricania. The diagnoses between these two genera cannot be resolved until more evidence is acquired.

Revision of the genus Homa Distant (Hemiptera: Cicadellidae: Typhlocybinae).

The leafhopper genus Homa Distant is revised. Four new species, H. osificata Xu, Dietrich Qin sp. nov., H. oretinia Xu, Dietrich Qin sp. nov., H. asilata Xu, Dietrich Qin sp. nov., and H. algulata Xu, Dietrich Qin sp. nov., are described from Thailand. H. haematoptilus (Kirkaldy) is redescribed based on specimens from the Oriental Region. All included species are illustrated and a key is provided to separate species for which males are known.

Unraveling the hierarchical genetic structure of tea green leafhopper, Matsumurasca onukii, in East Asia based on SSRs and SNPs.

Matsumurasca onukii (Matsuda, R. (1952). Oyo-Kontyu Tokyo, 8(1): 19-21), one of the dominant pests in major tea production areas in Asia, currently is known to occur in Japan, Vietnam, and China, and severely threatens tea production, quality, and international trade. To elucidate the population genetic structure of this species, 1633 single nucleotide polymorphisms (SNPs) and 18 microsatellite markers (SSRs) were used to genotype samples from 27 sites representing 18 geographical populations distributed throughout the known range of the species in East Asia. Analyses of both SNPs and SSRs showed that M. onukii populations in Yunnan exhibit high-genetic differentiation and structure compared with the other populations. The Kagoshima (JJ) and Shizuoka (JS) populations from Japan were separated from populations from China by SNPs, but clustered with populations from Jinhua (JH), Yingde (YD), Guilin (GL), Fuzhou (FZ), Hainan (HQ), Leshan (CT), Chongqing (CY), and Zunyi (ZY) tea plantations in China and the Vietnamese Vinh Phuc (VN) population based on the SSR data. In contrast, CT, CY, ZY, and Shaanxi (SX) populations clustered together based on SNPs, but were separated by SSRs. Both marker datasets identified significant geographic differentiation among the 18 populations. Various environmental and anthropogenic factors, including geographical barriers to migration, human transport of hosts (Camellia sinesis [L.] O. Kuntze) and adaptation of M. onukii to various local climatic zones possibly account for the rapid spread of this pest in Asia. The results demonstrate that SNPs from high-throughput genotyping data can be used to reveal subtle genetic substructure at broad scales in r-strategist insects.

Two new species and a new combination in the genus Ricanula Melichar, 1898 for Ricaniidae from China (Hemiptera: Fulgoromorpha).

Two new species of the genus Ricanula Melichar, 1898 within the family Ricaniidae (Hemiptera: Fulgoromorpha) from China are described and illustrated: R. curva sp. nov. and R. peronata sp. nov. Ricania cacaonis Chou et Lu, 1977 is redescribed and transferred to genus Ricanula. Ricanula pulverosa (Stl, 1865) is re-illustrated.

Characterization, Comparative Analysis and Phylogenetic Implications of Mitogenomes of Fulgoridae (Hemiptera: Fulgoromorpha).

The complete mitogenomes of nine fulgorid species were sequenced and annotated to explore their mitogenome diversity and the phylogenetics of Fulgoridae. All species are from China and belong to five genera: Dichoptera Spinola, 1839 (Dichoptera sp.); Neoalcathous Wang and Huang, 1989 (Neoalcathous huangshanana Wang and Huang, 1989); Limois Stål, 1863 (Limois sp.); Penthicodes Blanchard, 1840 (Penthicodes atomaria (Weber, 1801), Penthicodes caja (Walker, 1851), Penthicodes variegata (Guérin-Méneville, 1829)); Pyrops Spinola, 1839 (Pyrops clavatus (Westwood, 1839), Pyrops lathburii (Kirby, 1818), Pyrops spinolae (Westwood, 1842)). The nine mitogenomes were 15,803 to 16,510 bp in length with 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs) and a control region (A + T-rich region). Combined with previously reported fulgorid mitogenomes, all PCGs initiate with either the standard start codon of ATN or the nonstandard GTG. The TAA codon was used for termination more often than the TAG codon and the incomplete T codon. The nad1 and nad4 genes varied in length within the same genus. A high percentage of F residues were found in the nad4 and nad5 genes of all fulgorid mitogenomes. The DHU stem of trnV was absent in the mitogenomes of all fulgorids sequenced except Dichoptera sp. Moreover, in most fulgorid mitogenomes, the trnL2, trnR, and trnT genes had an unpaired base in the aminoacyl stem and trnS1 had an unpaired base in the anticodon stem. The similar tandem repeat regions of the control region were found in the same genus. Phylogenetic analyses were conducted based on 13 PCGs and two rRNA genes from 53 species of Fulgoroidea and seven outgroups. The Bayesian inference and maximum likelihood trees had a similar topological structure. The major results show that Fulgoroidea was divided into two groups: Delphacidae and ((Achilidae + (Lophopidae + (Issidae + (Flatidae + Ricaniidae)))) + Fulgoridae). Furthermore, the monophyly of Fulgoridae was robustly supported, and Aphaeninae was divided into Aphaenini and Pyropsini, which includes Neoalcathous, Pyrops, Datua Schmidt, 1911, and Saiva Distant, 1906. The genus Limois is recovered in the Aphaeninae, and the Limoisini needs further confirmation; Dichoptera sp. was the earliest branch in the Fulgoridae.

Two new empoascine leafhopper genera, Thaioasca and Mjolnirus, from Thailand (Hemiptera: Cicadellidae: Typhlocybinae), with a checklist of Empoascini in Thailand.

Two new microleafhopper genera of Empoascini, Thaioasca Wang, Xu Qin, gen. nov. and Mjolnirus Wang, Xu Qin, gen. nov., based on the type species, Thaioasca contaminata Wang, Xu Qin, sp. nov. and Mjolnirus mediolobus Wang, Xu Qin, sp. nov. are described from Thailand. Male habitus photos and illustrations of male genitalia of these two new species are given. A checklist of Empoascini from Thailand is also provided.

Taxonomic study of the genus Unkanodes (Hemiptera, Fulgoroidea, Delphacidae) from Pakistan, with description of a new species.

Unkanodes (Kwonianella) malamjabbensissp. nov. (Hemiptera, Delphacidae) is described and illustrated and U. latespinosa (Dlabola, 1957) is newly recorded from Malamjabbah, Swat, Pakistan. These two species represent the first records of the genus Unkanodes Fennah, 1956 from Pakistan. A key to the world's species of the genus Unkanodes is provided.

Sperm ultrastructure of Pochazia shantungensis (Chou & Lu) and Ricania speculum (Walker) (Hemiptera, Ricaniidae) with phylogenetic implications.

The sperm ultrastructure of two ricaniid species, Pochazia shantungensis (Chou & Lu) and Ricania speculum (Walker), was investigated using light and transmission electron microscopy. Both species have monoflagellate sperm, the shape and ultrastructure of the mature spermatozoon of these two species are similar in morphology, and 128 spermatozoa are organized into sperm bundles with their heads embedded in a homogenous matrix forming the spermatodesmata. The individual sperm is filiform and includes the head, neck and flagellum. The head is needle-like, with a bilayer acrosome and an inferior elongated nucleus which is formed of homogeneously compact and electron-dense chromatin. The neck region is indistinct and is comprised of the centriole and centriole adjunct with a homogeneous dense substance. The long flagellum has the typical 9 + 9 + 2 axoneme microtubule pattern and two symmetrical mitochondrial derivatives with an orderly array of cristae flanking both sides, and a pair of well-developed fishhook-shaped accessory bodies. Current evidence shows that ricaniid species have D-shaped mitochondrial derivatives in cross-section and a serrated electron-dense region. The phylogenetic relationship of Fulgoroidea with other superfamilies in Auchenorrhyncha is briefly discussed.

A new genus and species, Barbaropus flatus, from Ecuador with notes on Empoascini (Hemiptera: Cicadellidae: Typhlocybinae).

A new microleafhopper genus, Barbaropus gen. nov., is described based on a new species, Barbaropus flatus sp. nov. from Ecuador. Male habitus photos and illustrations of male genitalia are provided and differences between the new genus and closely related Neotropical genera are discussed. The relationship and the status of this new genus within the tribe are also discussed.

Genetic Diversity and Population Structure of Natural Lycorma delicatula (White) (Hemiptera: Fulgoridea) Populations in China as Revealed by Microsatellite and Mitochondrial Markers.

The spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), is a polyphagous pest originating in China and now widely distributed in Asian countries. This is one of the more serious forestry pests with a broad host range and causes significant economic losses. Molecular comparison has been used to investigate this pest's origin in China, and recent studies have explored the genetic structure among populations in Korea. However, the population structure of this pest in China remains poorly understood. In this study, 13 microsatellite markers and two mitochondrial markers (from nicotinamide adenine dinucleotid (NADH) dehydrogenase subunit 2 (ND2) and NADH dehydrogenase subunit 6 (ND6) regions) were used to reveal the origins and dispersal of L. delicatula based on a genetic analysis of Chinese populations from eight locations. Results show a low to high level of genetic differentiation among populations and significant genetic differentiation between both two clusters and four clusters. The network and phylogenetic analyses for mitochondrial haplotypes and population structure analyses for microsatellite datasets suggest that there is potential gene flow between geographical populations. The populations from Zhejiang and Fujian provinces may come from the other geographical populations in north China. The populations from Beijing, Henan, and Anhui provinces were regarded as the major source of migrants with a high number of migrants leaving (the effective number of migrants (Nem) = 24.40) and the low number of migrants entering (Nem = 2.05) based on the microsatellite dataset, where significant asymmetrical effective migrants to the other populations were detected by non-overlapping 95% confidence intervals.

Characterization of the complete mitochondrial genomes of two species of the genus Aphaena Guérin-Méneville (Hemiptera: Fulgoridae) and its phylogenetic implications.

The complete mitochondrial genomes (mitogenomes) of Aphaena (Callidepsa) amabilis and Aphaena (Aphaena) discolor nigrotibiata were sequenced. The mitogenomes of these two species are 16,237 bp and 16,116 bp in length with an A + T content of 77.9% and 77.0%, respectively. Each contains 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs) and a control region (A + T-rich region). All PCGs initiate with the standard start codon of ATN and terminate with the complete stop codon of TAA or TAG except for atp6, where nad1 ends with an incomplete T codon. All tRNAs have the typical clover-leaf structure except for trnS1 and trnV which have a reduced DHU arm. Moreover, these two mitogenomes have trnL2, trnR and trnT with an unpaired base in the acceptor stem. The putative A + T-rich region includes multiple types of tandem repeat regions. These phylogenetic analyses are reconstructed based on 13 protein-coding genes of 25 auchenorrhynchan mitogenomes, with both maximum likelihood and Bayesian analyses yielding robust identical phylogenetic trees. These results support a monophyletic Auchenorrhyncha and the relationship (Pyrops + (Lycorma + Aphaena)) within Fulgoridae.

Population structure and genetic differentiation of tea green leafhopper, Empoasca (Matsumurasca) onukii, in China based on microsatellite markers.

The tea green leafhopper, Empoasca (Matsumurasca) onukii Matsuda, is one of the dominant pests in major tea production regions of East Asia. Recent morphological studies have revealed variation in the male genitalic structures within and among populations. However, the genetic structure of this pest remains poorly understood. This study explores the genetic diversity and population structure of this pest in nineteen populations from the four main Chinese tea production areas using microsatellite markers, with one Japanese population also examined. The results show low to moderate levels of genetic differentiation with populations grouped into four clusters, i.e. the Jiangbei group, the Southwest group 1, the Southwest group 2 and the South China group. Populations from China have a close phylogenetic relationship but show significant isolation by distance. Lower genetic diversity and genetic differentiation of E. (M.) onukii were found in the Kagoshima population of Japan. Evidence for genetic bottlenecks was detected in the South China and Jiangnan populations. Population expansion was found in the Southwest, Jiangbei and Kagoshima populations. This is the most extensive study of the population genetics of this species and contributes to our understanding of its origin and evolutionary history.