Phylogeny and historical biogeography of leafhopper subfamily Evacanthinae (Hemiptera: Cicadellidae) based on morphological and molecular data

The Complete Mitochondrial Genomes of Five Nivanini Species (Hemiptera: Cicadellidae: Evacanthinae) With Phylogenetic Analysis

To delve deeper into the phylogenetic relationships within Cicadellidae and the taxonomic arrangement of Evacanthinae, our study focuses on the mitochondrial genome sequencing of five Nivanini species: Extensus latus, Concavepiana hamulusa, Sophonia nigrilineata, Sophonia microstaina, and Sophonia fuscomarginata. The results showed that the length of the five mitochondrial genomes ranged from 15,610 to 16,032 bp and included 37 typical genes. The A + T content of Nivanini ranged from 72.5% to 78.7%, which is consistent with that of other sequenced Evacanthinae species. All transfer RNAs (tRNAs) exhibit the typical cloverleaf secondary structure, except for trnS (AGY), which lacks the dihydrouracil (DHU) arm. With regard to protein-coding genes, all started with ATN codons, except for atp8, and most of them use TAA or TAG as termination codons. Using the Bayesian inference and maximum likelihood methods, a phylogenetic tree based on all 37 genes was constructed, with a total of 57 Cicadellidae species and two outgroups included as research objects. The analyses confirmed the monophyletic nature of each subfamily, highlighting Deltocephalinae as the oldest, distinctively parallel to the others.

A new species of leafhopper genus Sophonia (Evacanthinae: Cicadellidae: Hemiptera) from India

A new evacanthine leafhopper of the tribe Nirvanini, Sophonia submodesta sp. n. (Himachal Pradesh: Nauni), is described and illustrated from India. An annotated key is provided for the identification of all 17 species known under the genus Sophonia reported from the Indian subcontinent. Type material is deposited in the National Pusa Collection, Division of Entomology, Indian Agricultural Research Institute (ICAR-IARI), New Delhi, India.

A new species of Kana Distant representing the first record of Evacanthinae (Hemiptera: Cicadellidae) from Madagascar

Kana ranomafanensis sp. n. is described and illustrated based on specimens from montane rainforests in eastern Madagascar. This is the first record of the diverse and widely distributed leafhopper subfamily Evacanthinae from Madagascar. A revised diagnosis of Kana Distant is provided and the new species is compared to species from the Indomalayan and Afrotropical regions. Evidence from previous molecular divergence time analyses suggests that ancestors of the new species arrived in Madagascar via transoceanic dispersal. The ovipositor of the genus and the male genitalia of Kana decora (Melichar), previously known only from the female holotype from Sri Lanka, are illustrated for the first time.

Lapnana, a new genus of tribe Evacanthini (Hemiptera: Cicadellidae: Evacanthinae) from India

A new leafhopper genus Lapnana gen. nov. and species Lapnana ishanya, sp. nov. are described and illustrated from Arunachal Pradesh, India. The new genus is closely related to genus Onukindia Viraktamath and Webb but differs in having a median lamellate carina extending from the base to apex of the crown and ventral processes on the male pygofer.  

Sabahia polypodii gen. et sp. nov. (Hemiptera: Cicadellidae: Evacantihinae) and its Phylogenetic Position within the Nirvanini Tribe

In this paper, a new genus Sabahia Walczak & Gębicki with a new species Sabahia polypodii Walczak & Gębicki within the tribe Nirvanini is described. It originates from Sabah Province on Borneo (Malaysia, Sabah) and is most closely related to Decursusnirvana Gao & Zhang and Sinonirvana Gao & Zhang. It differs from these genera primarily with regard to the morphology of the male genitalia. Although it shows some resemblance to representatives of the genus Chudania Distant in the structure of the aedeagus, it can be clearly separated from this genus by the absence of a median carina from the facial part of the head. Details of the external morphology, as well as those of the male and female genitalia are documented (including scanning microscopy images). In addition, the phylogenetic relationships of several species within the subfamily Evacanthinae and related groups are discussed, based on comparative analyses of the genetic sequences for histone (H3) and the mitochondrial gene of cytochrome oxidase c (COI).

Mitogenomic phylogeny of Typhlocybinae (Hemiptera: Cicadellidae) reveals homoplasy in tribal diagnostic morphological traits

The subfamily Typhlocybinae is a ubiquitous, highly diverse group of mostly tiny, delicate leafhoppers. The tribal classification has long been controversial and phylogenetic methods have only recently begun to test the phylogenetic status and relationships of tribes. To shed light on the evolution of Typhlocybinae, we performed phylogenetic analyses based on 28 newly sequenced and 19 previously sequenced mitochondrial genomes representing all currently recognized tribes. The results support the monophyly of the subfamily and its sister-group relationship to Mileewinae. The tribe Zyginellini is polyphyletic with some included genera derived independently within Typhlocybini. Ancestral character state reconstruction suggests that some morphological characters traditionally considered important for diagnosing tribes (presence/absence of ocelli, development of hind wing submarginal vein) are homoplastic. Divergence time estimates indicate that the subfamily arose during the Middle Cretaceous and that the extant tribes arose during the Late Cretaceous. Phylogenetic results support establishment of a new genus, Subtilissimia Yan & Yang gen. nov., with two new species, Subtilissimia fulva Yan & Yang sp. nov. and Subtilissimia pellicula Yan & Yang sp. nov.; but indicate that two previously recognized species of Farynala distinguished only by the direction of curvature of the processes of the aedeagus are synonyms, that is, Farynala dextra Yan & Yang, 2017 equals Farynala sinistra Yan & Yang, 2017 syn. nov. A key to tribes of Typhlocybinae is provided.

Delivery of Rice Gall Dwarf Virus Into Plant Phloem by Its Leafhopper Vectors Activates Callose Deposition to Enhance Viral Transmission

Rice gall dwarf virus (RGDV) and its leafhopper vector Recilia dorsalis are plant phloem-inhabiting pests. Currently, how the delivery of plant viruses into plant phloem via piercing-sucking insects modulates callose deposition to promote viral transmission remains poorly understood. Here, we initially demonstrated that nonviruliferous R. dorsalis preferred feeding on RGDV-infected rice plants than viruliferous counterpart. Electrical penetration graph assay showed that viruliferous R. dorsalis encountered stronger physical barriers than nonviruliferous insects during feeding, finally prolonging salivary secretion and ingestion probing. Viruliferous R. dorsalis feeding induced more defense-associated callose deposition on sieve plates of rice phloem. Furthermore, RGDV infection significantly increased the cytosolic Ca²⁺ level in rice plants, triggering substantial callose deposition. Such a virus-mediated insect feeding behavior change potentially impedes insects from continuously ingesting phloem sap and promotes the secretion of more infectious virions from the salivary glands into rice phloem. This is the first study demonstrating that the delivery of a phloem-limited virus by piercing-sucking insects into the plant phloem activates the defense-associated callose deposition to enhance viral transmission.

DNA barcoding of some medicinally important plant species of Lamiaceae family in India

Several species of the Lamiaceae family are the primary source of bioactive aromatic oils and secondary metabolites, having broader applications in the cosmetics, pharmaceuticals, food, confectionery and liquor industries. Due to the scarcity of raw materials and high costs of this family's economically vital species, its products often adulterated to cater to the market's high demand. The present study provides a DNA based approach for identifying different species of this family. Henceforth, the performance of three already proposed barcode loci (matK, trnH-psbA and trnL) was examined for their PCR amplification and species recognition efficacy on various Lamiaceae species and cultivars using three different approaches such as pairwise genetic distance method, BLASTn and phylogenetic tree based on maximum likelihood (ML) analysis. Results illustrate that among all the DNA barcoding loci, matK locus can accurately and efficiently distinguish all the studied species followed by trnH-psbA and trnL. Present investigation may help diminish the illegal trade and events of adulteration of medicinally important plants species in genus Mentha, Ocimum and Plectranthus. This investigation will also help fulfil the scarcity of sequences of barcode loci of these species in the NCBI database. Apart from providing a molecular level reference for identifying processed herbal products, this technique also offers a convenient method for species identification and germplasm conservation of the Lamiaceae family.

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.

Two Distinct Genotypes of Spissistilus festinus (Say, 1830) (Hemiptera, Membracidae) in the United States Revealed by Phylogenetic and Morphological Analyses

Spissistilus festinus (Say, 1830) (Hemiptera: Membracidae) is a frequent pest of leguminous crops in the Southern United States, and a vector of grapevine red blotch virus. There is currently no information on the genetic diversity of S. festinus. In this study, populations of S. festinus were collected in 2015-2017 from various crops and geographic locations in the United States, and fragments of the mitochondrial cytochrome C oxidase 1 (mt-COI) gene and the nuclear internal transcribed spacer 2 (ITS2) region were characterized by polymerase chain reaction and sequencing. Maximum-likelihood and Bayesian analyses of the mt-COI and ITS2 sequences yielded similar phylogenetic tree topologies, revealing two distinct genetic S. festinus lineages with all of the specimens from California comprising one phylogenetic clade, alongside a single GenBank entry from Arizona, and all specimens from the Southeastern United States comprising a statistically-supported distinct clade, regardless of host and year of collection. The mt-COI gene fragment showed up to 10.8% genetic distance between the two phylogenetic clades. These results suggest the existence of two genotypes within S. festinus in the United States. The only distinct morphological trait between the two genotypes was a less elevated pronotum in the representative specimens from California, compared to the representative specimens from the Southeastern United States. Since this phenotypic feature is inconspicuous, a diagnostic polymerase chain reaction targeting a variable region of the mt-COI fragment was developed to reliably distinguish between the specimens of the two genotypes of S. festinus and to facilitate their specific identification.

Complete mitogenome of Olidiana ritcheriina (Hemiptera: Cicadellidae) and phylogeny of Cicadellidae

BACKGROUND

Coelidiinae, a relatively large subfamily within the family Cicadellidae, includes 129 genera and ∼1,300 species distributed worldwide. However, the mitogenomes of only two species (Olidiana sp. and Taharana fasciana) in the subfamily Coelidiinae have been assembled. Here, we report the first complete mitogenome assembly of the genus Olidiana.

METHODS

Specimens were collected from Wenxian County (Gansu Province, China) and identified on the basis of their morphology. Mitogenomes were sequenced by next-generation sequencing, following which an NGS template was generated, and this was confirmed using polymerase chain reaction and Sanger sequencing. Phylogenic trees were constructed using maximum likelihood and Bayesian analyses.

RESULTS

The mitogenome of O. ritcheriina was 15,166 bp long, with an A + T content of 78.0%. Compared with the mitogenome of other Cicadellidae sp., the gene order, gene content, gene size, base composition, and codon usage of protein-coding genes (PCGs) in O. ritcheriina were highly conserved. The standard start codon of all PCGs was ATN and stop codon was TAA or TAG; COII, COIII, and ND4L ended with a single T. All tRNA genes showed the typical cloverleaf secondary structure, except for trnSer, which did not have the dihydrouridine arm. Furthermore, the secondary structures of rRNAs (rrnL and rrnS) in O. ritcheriina were predicted. Overall, five domains and 42 helices were predicted for rrnL (domain III is absent in arthropods), and three structural domains and 27 helices were predicted for rrnS. Maximum likelihood and Bayesian analyses indicated that O. ritcheriina and other Coelidiinae members were clustered into a clade, indicating the relationships among their subfamilies; the main topology was as follows: (Deltocephalinae + ((Coelidiinae + Iassinae) + ((Typhlocybinae + Cicadellinae) + (Idiocerinae + (Treehopper + Megophthalminae))))). The phylogenetic relationships indicated that the molecular taxonomy of O. ritcheriina is consistent with the current morphological classification.

Phylogeny and revision of the Oriental leafhopper genus Amritodus (Hemiptera: Cicadellidae: Idiocerini)

The phylogeny of the Oriental leafhopper genus Amritodus is reconstructed, for the first time, based on 47 discrete morphological characters and DNA sequence data from one nuclear and two mitochondrial genes. The phylogenetic results show that Amritodus is not monophyletic, and its concept is narrowed here to include four species: Amritodus atkinsoni, Amritodus brevis, Amritodus brevistylus and Amritodus saeedi. The phylogenetic results support establishment of a new genus, Paramritodus gen. nov., with three new species,Paramritodus triangulus sp. nov. (type species), Paramritodus introflexus sp. nov., Paramritodus spatiosus sp. nov. and three species previously included in Amritodus: Paramritodus pistacious comb. nov., Paramritodus flavocapitatus comb. nov. and Paramritodus podocarpus comb. nov. In addition, Amritodus flavoscutatus is transferred from Amritodus to Hyalinocerus as Hyalinocerus flavoscutatus comb. nov. Keys to species of Amritodus and Paramritodus are provided.

New eurymeline leafhoppers (Hemiptera, Cicadellidae, Eurymelinae) from Eocene Baltic amber with notes on other fossil Cicadellidae

Two new extinct fossil cicadellid taxa from Eocene Baltic amber, representing the subfamily Eurymelinae (sensu lato), are described and illustrated, and their relationships to modern leafhoppers are discussed. Eoidiocerus emarginatusgen. and sp. n. is the oldest known representative of the tribe Idiocerini. The new genus resembles some modern Afrotropical and Indomalayan idiocerine genera but differs in having the gena relatively narrow. Archipedionis obscurusgen. and sp. n., is the first well-preserved fossil representative of Macropsini to be described in detail. Previous reports of this tribe from Baltic amber, while credible, included too little morphological information to assess their relationships. Additional comparative notes are provided for previously described fossil taxa belonging to Idiocerini and Macropsini from the Oligocene of Germany. The new combinations Oncopsis sepultus sepultus (Statz, 1950), comb. n. and Oncopsis sepultus austerus (Statz, 1950), comb. n. are proposed for taxa previously included in Bythoscopus Germar. The previously unplaced cicadellid fossil taxon Priscacutius denticulatus Poinar & Brown, 2018 from mid-Cretaceous Myanmar amber is newly placed in subfamily Signoretiinae, tribe Phlogisini, and represents the oldest known member of this subfamily, the only one known from the fossil record and only the second modern cicadellid subfamily confirmed by direct fossil evidence to have been present during the Cretaceous period.