The impact of geographic isolation and host shifts on population divergence of the rare cicada Subpsaltria yangi.

The contributions of divergent selection and spatial isolation to population divergence are among the main focuses of evolutionary biology. Here we employed integrated methods to explore genomic divergence, demographic history and calling-song differentiation in the cicada Subpsaltria yangi, and compared the genotype and calling-song phenotype of different populations occurring in distinct habitats. Our results indicate that this species comprises four main lineages with unique sets of haplotypes and calling-song structure, which are distinctly associated with geographic isolation and habitats. The populations occurring on the Loess Plateau underwent substantial expansion at âˆ¼0.130-0.115 Ma during the Last Interglacial. Geographic distance and host shift between pairs of populations predict genomic divergence, with geographic distance and acoustical signal together explaining > 60% of the divergence among populations. Differences in calling songs could reflect adaptation of populations to novel environments with different host plants, habitats and predators, which may have resulted from neutral divergence at the molecular level followed by natural selection. Geomorphic barriers and climate oscillations associated with Pleistocene glaciation may have been primary factors in shaping the population genetic structure of this species. Ultimately this may couple with a host shift in leading toward allopatric speciation in S. yangi, i.e., isolation by distance. Our findings improve understanding of divergence in allopatry of herbivorous insects, and may inform future studies on the molecular mechanisms underlying the association between genetic/phenotypic changes and adaptation of insects to novel niches and host plants.

Phylogenomics of the leafhopper genus Neoaliturus Distant, 1918 (Hemiptera: Cicadellidae: Deltocephalinae) reveals genetically divergent lineages in the invasive beet leafhopper.

Phylogenomic analysis based on nucleotide sequences of 398 nuclear gene loci for 67 representatives of the leafhopper genus Neoaliturus yielded well-resolved estimates of relationships among species of the genus. Subgenus Neoaliturus (Neoaliturus) is consistently paraphyletic with respect to Neoaliturus (Circulifer). The analysis revealed the presence of at least ten genetically divergent clades among specimens consistent with the previous morphology-based definition of the leafhopper genus "Circulifer" which includes three previously recognized "species complexes." Specimens of the American beet leafhopper, N. tenellus (Baker), collected from the southwestern USA consistently group with one of these clades, comprising specimens from the eastern Mediterranean. Some of the remaining lineages are consistent with ecological differences previously observed among eastern Mediterranean populations and suggest that N. tenellus, as previously defined, comprises multiple monophyletic species, distinguishable by slight morphological differences.

Structural basis for persulfide-sensing specificity in a transcriptional regulator.

Cysteine thiol-based transcriptional regulators orchestrate the coordinated regulation of redox homeostasis and other cellular processes by 'sensing' or detecting a specific redox-active molecule, which in turn activates the transcription of a specific detoxification pathway. The extent to which these sensors are truly specific in cells for a singular class of reactive small-molecule stressors, for example, reactive oxygen or sulfur species, is largely unknown. Here, we report structural and mechanistic insights into the thiol-based transcriptional repressor SqrR, which reacts exclusively with oxidized sulfur species such as persulfides, to yield a tetrasulfide bridge that inhibits DNA operator-promoter binding. Evaluation of crystallographic structures of SqrR in various derivatized states, coupled with the results of a mass spectrometry-based kinetic profiling strategy, suggest that persulfide selectivity is determined by structural frustration of the disulfide form. These findings led to the identification of an uncharacterized repressor from the bacterial pathogen Acinetobacter baumannii as a persulfide sensor.

Guilt by Association: DNA Barcoding-Based Identification of Potential Plant Hosts of Phytoplasmas from Their Insect Carriers.

Phytoplasmas are small phloem-restricted and insect-transmissible bacteria that infect many plant species, including important crops and ornamental plants, causing severe economic losses. Our previous studies screened phytoplasmas in hundreds of leafhoppers collected from natural habitats worldwide and identified multiple genetically different phytoplasmas in seven leafhopper species (potential insect vectors). As an initial step toward determining the impact of these phytoplasmas on the ecosystem, ribulose 1,5-biphosphate carboxylase large subunit (rbcL), a commonly used plant DNA barcoding marker, was employed to identify the plant species that the phytoplasma-harboring leafhoppers feed on. The DNA of 17 individual leafhoppers was PCR amplified using universal rbcL primers. PCR products were cloned, and five clones per amplicon were randomly chosen for Sanger sequencing. Moreover, Illumina high-throughput sequencing on selected PCR products was conducted and confirmed no missing targets in Sanger sequencing. The nucleotide BLAST results revealed 14 plant species, including six well-known plant hosts of phytoplasmas such as tomato, alfalfa, and maize. The remaining species have not been documented as phytoplasma hosts, expanding our knowledge of potential plant hosts. Notably, the DNA of tomato and maize (apparently cultivated in well-managed croplands) was detected in some phytoplasma-harboring leafhopper species sampled in non-crop lands, suggesting the spillover/spillback risk of phytoplasma strains between crop and non-crop areas. Furthermore, our results indicate that barcoding (or metabarcoding) is a valuable tool to study the three-way interactions among phytoplasmas, plant hosts, and vectors. The findings contribute to a better understanding of phytoplasma host range, host shift, and disease epidemiology.

Phylogenomics of Parasitic and Nonparasitic Lice (Insecta: Psocodea): Combining Sequence Data and Exploring Compositional Bias Solutions in Next Generation Data Sets.

The insect order Psocodea is a diverse lineage comprising both parasitic (Phthiraptera) and nonparasitic members (Psocoptera). The extreme age and ecological diversity of the group may be associated with major genomic changes, such as base compositional biases expected to affect phylogenetic inference. Divergent morphology between parasitic and nonparasitic members has also obscured the origins of parasitism within the order. We conducted a phylogenomic analysis on the order Psocodea utilizing both transcriptome and genome sequencing to obtain a data set of 2370 orthologous genes. All phylogenomic analyses, including both concatenated and coalescent methods suggest a single origin of parasitism within the order Psocodea, resolving conflicting results from previous studies. This phylogeny allows us to propose a stable ordinal level classification scheme that retains significant taxonomic names present in historical scientific literature and reflects the evolution of the group as a whole. A dating analysis, with internal nodes calibrated by fossil evidence, suggests an origin of parasitism that predates the K-Pg boundary. Nucleotide compositional biases are detected in third and first codon positions and result in the anomalous placement of the Amphientometae as sister to Psocomorpha when all nucleotide sites are analyzed. Likelihood-mapping and quartet sampling methods demonstrate that base compositional biases can also have an effect on quartet-based methods.[Illumina; Phthiraptera; Psocoptera; quartet sampling; recoding methods.].

Phylogenomics of flavobacterial insect nutritional endosymbionts with implications for Auchenorrhyncha phylogeny.

"Candidatus Sulcia muelleri" (Sulcia) is a diverse lineage of intracellular nutritional endosymbiotic bacteria strictly associated with auchenorrhynchous hemipteran insects. Sulcia has undergone long-term codiversification with its insect hosts but the phylogeny of these endosymbionts, their relationships to other bacteria, and the extent of their occurrence within various groups of Auchenorrhyncha remain inadequately explored. Comprehensive phylogenetic analyses of Sulcia and related bacteria were performed to elucidate its position relative to other members of Phylum Bacteroidetes and the degree of congruence to the phylogeny of its auchenorrhynchous hosts. Maximum likelihood (ML) and maximum parsimony (MP) analyses of Flavobacteriales based on genomic data from 182 bacterial strains recover a monophyletic Sulcia within a larger clade of flavobacterial insect endosymbionts, closely related to Weeksellaceae. Molecular divergence time analysis of Sulcia dates the origin of Sulcia at approximately 339.95 million years ago (Myr) and the initial divergence within Sulcia at approximately 256.91 Myr but these are considered underestimates due to the tendency for endosymbionts to evolve at higher rates compared to their free-living relatives. Screening of 96 recently sequenced hemipteran transcriptomes revealed that 73 of these species, all Auchenorrhyncha, harbored Sulcia. Phylogenetic analysis of 131 orthologous genes plus 16S rRNA for 101 Sulcia strains, representing six fulgoroid families and all the families of Cicadomorpha except Tettigarctidae, recover largely congruent phylogenies between Sulcia and Auchenorrhyncha. The phylogeny of Sulcia strongly supports the superfamily relationships Fulgoroidea + (Cicadoidea + (Cercopoidea + Membracoidea)). Relationships within individual superfamilies are also largely concordant, with the few areas of apparent incongruence between Sulcia and insect genes attributable to low branch support in one or both datasets. These results suggest that analysis of Sulcia phylogeny may contribute to resolution of contentious aspects of Auchenorrhyncha phylogeny.

Comparative analysis of mitochondrial genomes of Nirvanini and Evacanthini (Hemiptera: Cicadellidae) reveals an explicit evolutionary relationship.

Mitogenomes of five leafhopper species, Chudania hellerina and Concaveplana rufolineata in Nirvanini, Carinata rufipenna, Evacanthus danmainus and E. heimianus representing Evacanthini, were sequenced. The lengths of these five mitogenomes range from 15,044 (C. hellerina) to 15,680 bp (E. heimianus). All five mitogenomes exhibit similar base composition, gene size and codon usage of protein-coding genes. All 22 tRNA genes have typical cloverleaf secondary structures, except for trnS1 (AGN) which appears to lack the dihydrouridine arm. The two included Nirvanini species employ the anticodon TCT instead of the commonly used GCT in trnS1 (AGN). Genes nad2, atp8 and nad6 were highly variable while cox1 and cob showed the lowest nucleotide diversity. Phylogenetic analyses of two concatenated nucleotide datasets, incorporating the newly sequenced taxa and other available membracoid mitogenomes, recovered each included leafhopper subfamily as monophyletic with evacanthine tribes Nirvanini and Evacanthini forming monophyletic sister clades. A relationship among Evacanthinae, Cicadellinae and Typhlocybinae received moderate branch support.

A multi-gene phylogenetic analysis of the leafhopper subfamily Typhlocybinae (Hemiptera: Cicadellidae) challenges the traditional view of the evolution of wing venation.

Genera of the diverse leafhopper subfamily Typhlocybinae have traditionally been classified into tribes primarily based on characters of the wing venation and an intuitive phylogeny of this group was previously proposed based on the hypothetical pattern of wing vein evolution. Some recent authors suggested that wing vein characters are not always reliable but few attempts have been made to examine the status and relationships of typhlocybine tribes using rigorous phylogenetic analyses. Phylogenetic analysis of a dataset comprising DNA sequences from five gene regions (H3, H2A, 28S rDNA D2, 16S rDNA, and COI with a total length of 2413 bps) and 61 species representing six previously recognized tribes of Typhlocybinae provides strong support for the monophyly of the subfamily and five of the previously recognized tribes. Most branches received moderate to strong maximum likelihood bootstrap support. The following intertribal relationships were recovered: (Alebrini + Empoascini) + ((Dikraneurini + Erythroneurini) + Typhlocybini). Maximum likelihood analysis recovered Zyginellini (treated as a separate tribe by some authors) as sister to Typhlocybini with low branch support, but the former tribe was derived from within the latter in Bayesian analysis of the same dataset and relationships within Typhlocybini (sensu lato) were generally poorly resolved in both analyses. The relationship of Typhlocybini to other tribes is also unstable, suggesting that more data are needed to resolve the position of this tribe with confidence. Parts of the phylogeny receiving strong support in both analyses contradict the traditional view that Alebrini, the only tribe retaining an appendix in the forewing, is the earliest diverging lineage and possibly gave rise to the other tribes. Ancestral state reconstructions indicate that characters of the wing venation traditionally used for diagnosing typhlocybine tribes are generally conservative but exhibit some homoplasy and may not, by themselves, be reliable for recognizing monophyletic groups within this subfamily.

Phylogenomics and the evolution of hemipteroid insects.

Hemipteroid insects (Paraneoptera), with over 10% of all known insect diversity, are a major component of terrestrial and aquatic ecosystems. Previous phylogenetic analyses have not consistently resolved the relationships among major hemipteroid lineages. We provide maximum likelihood-based phylogenomic analyses of a taxonomically comprehensive dataset comprising sequences of 2,395 single-copy, protein-coding genes for 193 samples of hemipteroid insects and outgroups. These analyses yield a well-supported phylogeny for hemipteroid insects. Monophyly of each of the three hemipteroid orders (Psocodea, Thysanoptera, and Hemiptera) is strongly supported, as are most relationships among suborders and families. Thysanoptera (thrips) is strongly supported as sister to Hemiptera. However, as in a recent large-scale analysis sampling all insect orders, trees from our data matrices support Psocodea (bark lice and parasitic lice) as the sister group to the holometabolous insects (those with complete metamorphosis). In contrast, four-cluster likelihood mapping of these data does not support this result. A molecular dating analysis using 23 fossil calibration points suggests hemipteroid insects began diversifying before the Carboniferous, over 365 million years ago. We also explore implications for understanding the timing of diversification, the evolution of morphological traits, and the evolution of mitochondrial genome organization. These results provide a phylogenetic framework for future studies of the group.

A timetree for phytoplasmas (Mollicutes) with new insights on patterns of evolution and diversification.

The first comprehensive timetree is presented for phytoplasmas, a diverse group of obligate intracellular bacteria restricted to phloem sieve elements of vascular plants and tissues of their hemipteran insect vectors. Maximum likelihood-based phylogenetic analysis of DNA sequence data from the 16S rRNA and methionine aminopeptidase (map) genes yielded well resolved estimates of phylogenetic relationships among major phytoplasma lineages, 16Sr groups and known strains of phytoplasmas. Age estimates for divergences among two major lineages of Mollicutes based on a previous comprehensive bacterial timetree were used to calibrate an initial 16S timetree. A separate timetree was estimated based on the more rapidly-evolving map gene, with an internal calibration based on a recent divergence within two related 16Sr phytoplasma subgroups in group 16SrV thought to have been driven by the introduction of the North American leafhopper vector Scaphoideus titanus Ball into Europe during the early part of the 20th century. Combining the resulting divergence time estimates into a final 16S timetree suggests that evolutionary rates have remained relatively constant overall through the evolution of phytoplasmas and that the origin of this lineage, at ~641 million years ago (Ma), preceded the origin of land plants and hemipteran insects. Nevertheless, the crown group of phytoplasmas is estimated to have begun diversifying ~316 Ma, roughly coinciding with the origin of seed plants and Hemiptera. Some phytoplasma groups apparently associated with particular plant families or insect vector lineages generally arose more recently than their respective hosts and vectors, suggesting that vector-mediated host shifts have been an important mechanism in the evolutionary diversification of phytoplasmas. Further progress in understanding macroevolutionary patterns in phytoplasmas is hindered by large gaps in knowledge of the identity of competent vectors and lack of data on phytoplasma associations with non-economically important plants.

Correction to: Assessing genotype-phenotype associations in three dorsal colour morphs in the meadow spittlebug Philaenus spumarius (L.) (Hemiptera: Aphrophoridae) using genomic and transcriptomic resources.

Following publication of the original article [1], it has been brought to the authors' attention that in their paper (Rodrigues et al. 2016) they reported the genome size based on 2C values (diploid genome) when it is more common to present it as 1C value.

Genetic divergence, population differentiation and phylogeography of the cicada Subpsaltria yangi based on molecular and acoustic data: an example of the early stage of speciation?

BACKGROUND: Geographical isolation combined with historical climatic fluctuations have been identified as two major factors that contribute to the formation of new species. On the other hand, biotic factors such as competition and predation are also able to drive the evolution and diversification of organisms. To determine whether geographical barriers contributed to population divergence or speciation in the rare endemic cicada Subpsaltria yangi the population differentiation, genetic structure and phylogeography of the species were investigated in the Loess Plateau and adjacent areas of northwestern China by analysing mitochondrial and nuclear DNA and comparing the calling song structure of 161 male individuals. RESULTS: The results reveal a low level of genetic differentiation and relatively simple phylogeographic structure for this species, but two independent clades corresponding to geographically isolated populations were recognised. Genetic and geographical distances were significantly correlated among lineages. Results of divergence-time estimation are consistent with a scenario of isolation due to glacial refugia and interglacial climate oscillation in northwestern China. Significant genetic divergence was found between the population occurring in the Helan Mountains and other populations, and recent population expansion has occurred in the Helan Mountains and/or adjacent areas. This population is also significantly different in calling song structure from other populations. CONCLUSIONS: Geographical barriers (i.e., the deserts and semi-deserts surrounding the Helan Mountains), possibly coupled with related ecological differences, may have driven population divergence and allopatric speciation. This provides a possible example of incipient speciation in Cicadidae, improves understanding of population differentiation, acoustic signal diversification and phylogeographic relationships of this rare cicada species of conservation concern, and informs future studies on population differentiation, speciation and phylogeography of other insects with a high degree of endemism in the Helan Mountains and adjacent areas.

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.

Assessing genotype-phenotype associations in three dorsal colour morphs in the meadow spittlebug Philaenus spumarius (L.) (Hemiptera: Aphrophoridae) using genomic and transcriptomic resources.

BACKGROUND: Colour polymorphisms are common among animal species. When combined with genetic and ecological data, these polymorphisms can be excellent systems in which to understand adaptation and the molecular changes underlying phenotypic evolution. The meadow spittlebug, Philaenus spumarius (L.) (Hemiptera, Aphrophoridae), a widespread insect species in the Holarctic region, exhibits a striking dorsal colour/pattern balanced polymorphism. Although experimental crosses have revealed the Mendelian inheritance of this trait, its genetic basis remains unknown. In this study we aimed to identify candidate genomic regions associated with the colour balanced polymorphism in this species. RESULTS: By using restriction site-associated DNA (RAD) sequencing we were able to obtain a set of 1,837 markers across 33 individuals to test for associations with three dorsal colour phenotypes (typicus, marginellus, and trilineatus). Single and multi-association analyses identified a total of 60 SNPs associated with dorsal colour morphs. The genome size of P. spumarius was estimated by flow cytometry, revealing a 5.3 Gb genome, amongst the largest found in insects. A partial genome assembly, representing 24% of the total size, and an 81.4 Mb transcriptome, were also obtained. From the SNPs found to be associated with colour, 35% aligned to the genome and 10% to the transcriptome. Our data suggested that major loci, consisting of multi-genomic regions, may be involved in dorsal colour variation among the three dorsal colour morphs analysed. However, no homology was found between the associated loci and candidate genes known to be responsible for coloration pattern in other insect species. The associated markers showed stronger differentiation of the trilineatus colour phenotype, which has been shown previously to be more differentiated in several life-history and physiological characteristics as well. It is possible that colour variation and these traits are linked in a complex genetic architecture. CONCLUSIONS: The loci detected to have an association with colour and the genomic and transcriptomic resources developed here constitute a basis for further research on the genetic basis of colour pattern in the meadow spittlebug P. spumarius.

Review of the genera Paulomanus Young, 1952 and Beamerana Young, 1952 (Hemiptera: Cicadellidae: Typhlocybinae: Empoascini) with description of a new species from Argentina.

The Neotropical microleafhopper genera Paulomanus and Beamerana are redescribed based on study of type material and newly collected specimens. Paulomanus is recorded for the first time from Argentina and a new species, P. falciformis n. sp., is described. Detailed morphological description and illustration of the new species and a key to males of the known species of Paulomanus are provided. A key to genera of the New World Empoascini is also provided.

New species and records of Asymmetrasca (Hemiptera: Cicadellidae: Typhlocybinae: Empoascini) from China and name changes in Empoasca (Matsumurasca).

Six new species of Asymmetrasca Dlabola are described from China: A. dahaituoensis, A. helica, A. hypercurvata, A. liaoensis, A. reflexilis, A. uncus spp. nov. In addition, A. cienka Dworakowska, 1982, n. comb.; A. decedens Paoli, 1932 and A. sakaii Dworakowska 1971, n. comb., are recorded from China for the first time. The following additional new combinations from Empoasca are also proposed: A. cisiana (Dworakowska, 1971); A. kaicola (Dworakowska, 1982), A. lutowa (Dworakowska, 1971), A. mona (Dworakowska, 1994), A. nipponica (Dworakowska 1982), A. rybiogon (Dworakowska, 1971), and A. uniprossicae (Sohi, 1977). Empoasca (Empoasca) kishtwarensis Sharma, 1984 is proposed as a new synonym of Asymmetrasca kaicola (Dworakowska, 1982). Habitus photos and illustrations of the male genitalia of the new species and a key to Chinese species are provided. New names are proposed to replace two junior homonyms in Empoasca (Matsumurasca).

Climate change may drive the distribution of tribe Zyginelline pests in China and the Indo-China Peninsula to shift towards higher latitude river-mountain systems.

BACKGROUND: Tribe Zyginelline leafhoppers can transmit plant viruses and are important pests that affect agriculture, forestry, and animal husbandry, causing serious economic losses. The potential distribution patterns of Zyginellini will change under climate change. Therefore, the best-performing random forest and maximum entropy models among 12 commonly used ecological niche models, alongside an ensemble model, were selected to predict the changes in habitat suitability distribution of Zyginellini under current and future climate scenarios [represented by two shared socio-economic pathways (SSPs), namely SSP126 and SSP585, for three periods (2050s, 2070s, and 2090s)] in China and the Indo-China Peninsula for the first time. RESULTS: The results revealed that the distribution of Zyginellini was mainly dominated by minimum temperature of coldest month. Under current and future climate scenarios, Zyginellini was mostly distributed southeast of the 400 mm equivalent precipitation line in China, and Vietnam. Under the future SSP126 scenario, the alert areas will mainly be concentrated in Hunan, Jiangxi, Zhejiang, Anhui, and Hebei in China, alongside Myanmar and Thailand in the Indo-China Peninsula. Meanwhile, in the SSP585 scenario, the alert areas in China will increase, whereas there will be little change in the Indo-China Peninsula. Interestingly, from the current to the future, the cores of Zyginelline distribution occurred around rivers and mountains, and shifted from Guizhou along the Yuanjiang River system to higher latitudes in Hunan. CONCLUSION: Zyginellini prefers higher latitude river-mountain systems under climate change. Our results will contribute to effective pest control strategies and biogeographical research for Zyginellini alongside other Cicadellidae insects. © 2023 Society of Chemical Industry.

Genetic differentiation and phylogeography of Erythroneurini (Hemiptera, Cicadellidae, Typhlocybinae) in the southwestern karst area of China.

Erythroneurini is the largest tribe of the microleafhopper subfamily Typhlocybinae. Most prior research on this tribe has focused on traditional classification, phylogeny, and control of agricultural pests, and the phylogeography of the group remains poorly understood. In this study, the mitochondrial genomes of 10 erythroneurine species were sequenced, and sequences of four genes were obtained for 12 geographical populations of Seriana bacilla. The new sequence data were combined with previously available mitochondrial DNA sequence data and analyzed using Bayesian and Maximum-Likelihood-based phylogenetic methods to elucidate relationships among genera and species and estimate divergence times. Seriana was shown to be derived from within Empoascanara. Phylogeographic and population genetic analysis of the endemic Chinese species Seriana bacilla suggest that the species diverged about 54.85 Mya (95% HPD: 20.76-66.23 million years) in the Paleogene period and that population divergence occurred within the last 14 million years. Ancestral area reconstruction indicates that Seriana bacilla may have originated in the central region of Guizhou, and geographical barriers are the main factors affecting gene flow among populations. Ecological niche modeling using the MaxEnt model suggests that the distribution of the species was more restricted in the past but is likely to expand in the future years 2050 and 2070.

Mitogenomic Analysis and Phylogenetic Implications for the Deltocephaline Tribe Chiasmini (Hemiptera: Cicadellidae: Deltocephalinae).

The grassland leafhopper tribe Chiasmini (Cicadellidae: Deltocephalinae) presently comprises 324 described species worldwide, with the highest species diversity occurring in the Nearctic region but a greater diversity of genera occurring in the Old World. In China, this tribe comprises 39 described species in 11 genera, but the fauna remains understudied. The complete mitogenomes of three species of this tribe have been sequenced previously. In order to better understand the phylogenetic position of Chiasmini within the subfamily Deltocephalinae and to investigate relationships among Chiasmini genera and species, we sequenced and analyzed the complete mitogenomes of 13 species belonging to seven genera from China. Comparison of the newly sequenced mitogenomes reveals a closed circular double-stranded structure containing 37 genes with a total length of 14,805 to 16,269 bp and a variable number of non-coding A + T-rich regions. The gene size, gene order, gene arrangement, base composition, codon usage, and secondary structure of tRNAs of the newly sequenced mitogenomes of these 13 species are highly conserved in Chiasmini. The ATN codon is commonly used as the start codon in protein-coding genes (PCGs), except for ND5 in Doratura sp. and ATP6 in Nephotettix nigropictus, which use the rare GTG start codon. Most protein-coding genes have TAA or TAG as the stop codon, but some genes have an incomplete T stop codon. Except for the tRNA for serine (trnS1(AGN)), the secondary structure of the other 21 tRNAs is a typical cloverleaf structure. In addition to the primary type of G-U mismatch, five other types of tRNA mismatches were observed: A-A, A-C, A-G, U-C, and U-U. Chiasmini mitochondrial genomes exhibit gene overlaps with three relatively stable regions: the overlapping sequence between trnW and trnC is AAGTCTTA, the overlapping sequence between ATP8 and ATP6 is generally ATGATTA, and the overlapping sequence between ND4 and ND4L is generally TTATCAT. The largest non-coding region is the control region, which exhibits significant length and compositional variation among species. Some Chiasmini have tandem repeat structures within their control regions. Unlike some other deltocephaline leafhoppers, the sequenced Chiasmini lack mitochondrial gene rearrangements. Phylogenetic analyses of different combinations of protein-coding and ribosomal genes using maximum likelihood and Bayesian methods under different models, using either amino acid or nucleotide sequences, are generally consistent and also agree with results of prior analyses of nuclear and partial mitochondrial gene sequence data, indicating that complete mitochondrial genomes are phylogenetically informative at different levels of divergence within Chiasmini and among leafhoppers in general. Apart from Athysanini and Opsiini, most of the deltocephaline tribes are recovered as monophyletic. The results of ML and BI analyses show that Chiasmini is a monophyletic group with seven monophyletic genera arranged as follows: ((Zahniserius + (Gurawa + (Doratura + Aconurella))) + (Leofa + (Exitianus + Nephotettix))).

High-quality genome assemblies for nine non-model North American insect species representing six orders (Insecta: Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Neuroptera).

Field-collected specimens were used to obtain nine high-quality genome assemblies from a total of 10 insect species native to prairies and savannas of central Illinois (USA): Mellilla xanthometata (Lepidoptera: Geometridae), Stenolophus ochropezus (Coleoptera: Carabidae), Forcipata loca (Hemiptera: Cicadellidae), Coelinius sp. (Hymenoptera: Braconidae), Thaumatomyia glabra (Diptera: Chloropidae), Brachynemurus abdominalus (Neuroptera: Myrmeleontidae), Catonia carolina (Hemiptera: Achilidae), Oncometopia orbona (Hemiptera: Cicadellidae), Flexamia atlantica (Hemiptera: Cicadellidae) and Stictocephala bisonia (Hemiptera: Membracidae). Sequencing library preparation from single specimens was successful despite extremely small DNA yields (<0.1 µg) for some samples. Additional sequencing and assembly workflows were adapted to each sample depending on the initial DNA yield. PacBio circular consensus (CCS/HiFi) or continuous long reads (CLR) libraries were used to sequence DNA fragments up to 50 kb in length, with Illumina sequenced linked-reads (TellSeq libraries) and Omni-C libraries used for scaffolding and gap-filling. Assembled genome sizes ranged from 135 MB to 3.2 GB. The number of assembled scaffolds ranged from 47 to >13,000, with the longest scaffold per assembly ranging from ~23 to 439 Mb. Genome completeness was high, with BUSCO scores ranging from 85.5% completeness for the largest genome (Stictocephala bisonia) to 98.8% completeness for the smallest genome (Coelinius sp.). The unique content was estimated using RepeatMasker and GenomeScope2, which ranged from 50.7% to 75.8% and roughly decreased with increasing genome size. Structural annotation predicted a range of 19,281-72,469 protein models for sequenced species. Sequencing costs per genome at the time ranged from US$3-5k, averaged ~1600 CPU-hours on a high-performance cluster and required approximately 14 h of bioinformatics analyses with samples using PacBio HiFi data. Most assemblies would benefit from further manual curation to correct possible scaffold misjoins and translocations suggested by off-diagonal or depleted signals in Omni-C contact maps.