Leafhopper Species Research Articles

The complete mitochondrial genome of Aconurella prolixa (Lethierry 1885) (Hemiptera: Cicadellidae: Deltocephalinae: Chiasmini)

The complete mitochondrial genome of the widespread leafhopper species Aconurella prolixa (Hemiptera: Cicadellidae: Deltocephalinae: Chiasmini) was obtained via next-generation sequencing. This mitochondrial genome is 14,832 bp in length with the 37 classical eukaryotic mitochondrial genes and a control region. All 13 protein-coding genes (PCGs) are initiated with ATN, except ND5 uses TTG as the start codon, and terminate with TAA or TAG with the exception of COX2 and ND4 which use a single T residue as the stop codon. Twenty-one of the 22 transfer RNA (tRNAs) genes have the typical clover-leaf structure except for trnS1. Unlike some other species of deltocephalinae, no tRNA rearrangements were detected. The monophyly of Cicadellidae and Deltocephalinae, as well as the monophyly of Chiasmini, with a sister relationship between A. prolixa and (Exitianus indicus + Nephotettix cincticeps) is supported by Bayesian inference phylogenetic analyses based on 13 PCGs.

Eight Decades of Dalbulus maidis (DeLong & Wolcott) (Hemiptera, Cicadellidae) in Brazil: What We Know and What We Need to Know.

The corn leafhopper Dalbulus maidis (DeLong & Wolcott) is one of the most important maize (Zea mays L.) pests in Latin America because of its ability to efficiently transmit pathogens [maize bushy stunt phytoplasma (MBSP) and corn stunt spiroplasma-Spiroplasma kunkelli Whitcomb et al. (CSS)] associated with corn stunt disease complex and maize rayado fino virus (MRFV). This leafhopper species, considered a secondary pest until a few years ago, was first reported in Brazil in 1938. Since 2015, corn stunt diseases have been the main phytosanitary threat to corn production in Brazil, and D. maidis has assumed the status of a key pest of the crop. In this study, we gathered pertinent information about the corn leafhopper, from the time it was first recorded in Brazil. Aspects such as origin, association with maize, bioecology, geographical distribution in the Americas, and its congeners are addressed. We present a history of studies performed with this species in the country, its importance as a pest, host plants, and survival strategies during the maize off-season. Based on the available scientific knowledge, the main management strategies for insect vectors and diseases are discussed. Finally, the main knowledge gaps for this insect vector and the prospects for future studies and actions to mitigate the damage caused by insect vectors in maize crops in Brazil are presented and discussed.

First report of Flavescence dorée phytoplasma identification and characterization in three species of leafhoppers

Phytoplasma strains were sporadically found in specimens of Hishimonus hamatus, Japananus hyalinus and Graphocephala fennahi caught during an entomological survey conducted in Southern Switzerland on the edges and woods surrounding cultivated vineyards in 2017. The subsequent molecular characterization of the pathogens allowed to identify them as strains strictly associated to Flavescence dorée, a serious European grapevine disease, transmitted from vine to vine by the leafhopper Scaphoideus titanus. In particular, M12 and M50 genotypes were found in H. hamatus and J. hyalinus, respectively, while G. fennahi harboured mixed phytoplasma genotypes with at least two different Flavescence dorée isolates. The potential importance of these findings in the frame of the Flavescence dorée epidemics in Europe is discussed.

Population dynamics and parasitism rate of leafhopper species (Hemiptera: Cicadellidae) in maize (Zea mays L.) crop

Maize is an important crop in Turkey that is infested by various leafhopper species during the whole season. Monitoring population dynamics and parasitism rate of these species would help to devise effective management practices. This study determined population dynamics of four leafhopper species, i.e., Zyginidia sohrab Zachvatkin, 1947, Empoasca decipiens Paoli, 1930 and Psammotettix striatus (Linnaeus, 1758) in second maize crop. Similarly, population dynamics and parasitism rate of egg parasitoid (Anagrus atomus) of these leafhopper species was also studied through July to November 2018 in Akçakale, Harran and Haliliye districts of Şanlıurfa province, Turkey. Population density of all species significantly varied among studied districts with the highest density of A. atomus recorded on 7 September with 30 adults/trap in Haliliye district. The parasitism rate on Z. sohrab eggs was 78% in Akçakale, 82% in Harran and 63% in Haliliye district. It was followed by E. decipiens with 18% in Akçakale, 14% in Harran and 32% in Haliliye. The highest population density of Z. sohrab was recorded on 21 September in Akçakale (4328 adults/trap), Harran (3920 adults/trap) and Haliliye (4592 adults/trap). Similarly, E. decipiens had the highest (1216 adults/trap) population density on 10 August in Harran, 12 October (368 adult/trap) in Akçakale and 17 August (2184 adults/trap) in Haliliye. Population dynamics of leafhoppers and their egg parasitoid coincided with each other. The parasitism rate was lower than other provinces in Turkey which is owed to high pesticide use in Şanlıurfa province. Therefore, chemical control should be decided by considering population development of beneficial insect species.

Characterization of the morphology and complete mitochondrial genomes of Eupteryx minusula and Eupteryx gracilirama (Hemiptera: Cicadellidae: Typhlocybinae) from Karst area, Southwest China.

BackgroundThe hemipteran insect family Cicadellidae (leafhoppers) includes >2,600 valid genera and >22,000 valid species worldwide, including >2,000 species in China. Typhlocybinae, second largest subfamilies of Cicadellidae, is widely distributed in the six major zoogeographic regions of the world, including >4,000 species worldwide and >1,000 species in China. Previously, morphological analysis are often effective to the way of taxonomy, but it did not combine with molecular biology. Therefore, morphology and mitochondrial genomes (mitogenomes) of two leafhopper species, Eupteryx (Eupteryx) minuscula Lindberg, 1929 and Eupteryx (Stacla) gracilirama Hou, Zhang & Huang, 2016 were studied and analyzed. This study analyzed the morphological and molecular characteristics of the two leafhoppers, and showed whether the results of the two identifications were consistent.MethodsBased on the method of comparison, mitogenomes and morphology were analyzed to prove the relationship between the two leafhoppers.ResultsAlthough two focal species are classified in two different subgenera of the same genus, they still share many morphological features, such as the moderately produced crown fore margin; the milky yellow apical part of scutellum; the pronotum, basal triangles of scutellum, and forewing are dark with several colorless patches on the surface; the light yellow face, without any spots or stripes, and so on. The circular mitogenomes are 16,944 bp long in E. minuscula (GenBank: MN910279) and 17,173 bp long in E. gracilirama (GenBank: MT594485). All of the protein-coding genes are starting with ATN, except for some in mitogenome, which has a single T or TAN as a stop codon. All tRNAs have the typical cloverleaf-shaped structure except for trnS1 (AGN) (E. minuscula) which has a reduced DHU arm. Moreover, these two mitogenomes have trnR with an unpaired base in the acceptor stem. The phylogenetic relationships between E. minuscula and E. gracilirama in respect to related lineages were reconstructed using Maximum likelihood and Maximum parsimony analyses.DiscussionThe result showed that the tribe Typhlocybini is a sister to the tribes Erythroneurini and Empoascini, and five genera, Bolanusoides, Typhlocyba, Eupteryx, Zyginella and Limassolla are forming a single clade. E. minuscula and E. gracilirama are clustered together, supporting the monophyly of the genus Eupteryx. The above conclusions are consistent with the traditional classification of the subfamily.

A new leafhopper (Hemiptera: Cicadellidae) from late Eocene Rovno amber described based on an adult and associated last-instar nymph from Perebrody (Ukraine)

Rovnoxestus rasnitsyni gen. & sp. nov. is described from Eocene Rovno amber based on an adult female and fifth-instar nymph collected at a recently discovered locality at Perebrody, Rovno Province, Ukraine. The new fossil taxon is tentatively placed in Aphrodinae and resembles Xestocephalites Dietrich & Gonçalves from Eocene Baltic amber but has the hind femur macrosetal formula 2+2+1 and hind tarsomere I in both nymph and adult with an elongated inner preapical seta. This is the first species of Eocene leafhopper for which both the adult and nymph are described in detail.

A dichotomous key and checklist for Mexican Athysanini leafhopper genera (Hemiptera: Cicadellidae) with a new species from the Oaxacan dry tropical forest

Most Neotropical forest-dwelling leafhopper species are rare and exhibit limited distributions. The Mexican leafhopper fauna is known to be highly diverse and identification of genera and species is difficult because no attempts have been made to provide comprehensive identification tools for the fauna. Here, a dichotomous key to all genera recognized within Mexico of the diverse but little studied leafhopper tribe Athysanini is provided. Spinulana josefinae Pinedo-Escatel sp. n. is described and illustrated based on specimens collected in the dry tropical forest of Oaxacan mountains. A total of 46 genera and 146 species are now recognized in the checklist of Athysanini of Mexico. Notes on type repositories, distributional data and maps, and selected references are provided.

STUBBORN DISEASE OF CITRUS CAUSED BY SPIROPLASMA CITRI: A SHORT NOTE

Citrus fruit is considered a very nutritious and delicious diet. Citrus consists of lemon, oranges, mandarin, and grapefruit which have economic value in the world. Significant losses occur in citrus due to numerous diseases. Among various diseases, citrus trees are seriously affected by a phytopathogenic mollicute Spiroplasma citri which causes stubborn disease. S. citri is transovarially transmitted by several leafhopper species. Symptoms include smaller and cupped leaves, small size, crook fruits with aborted seeds. Moreover, irregularity on the fruits such as different sizes, shapes, and typically lighter, smaller fruits than its healthy counterpart has also been observed. The affected fruits often drop before maturity. The color inversion is often seen with the stylar end remaining green and the peduncle end showing color. Various molecular and biochemical tests are conducted to identify S. citri. Under in-vitro conditions, S. citri grows on SP4 media where a fried egg-like shaped colony is observed. Keeping the importance of the stubborn citrus disease, the present short note briefly described the symptomology, detection, transmission, and management.

Taxonomic studies on Idiocerini Leafhoppers (Hemiptera: Cicadellidae: Eurymelinae: Idiocerini) of Sri Lanka

Seven species of Leafhoppers belong to the tribe: Idiocerini of Subfamily Eurymelinae in Family Cicadellidae, are reported from Sri Lanka based on the field study. Four species of <em>Idioscopus, </em>and each one<em> </em>species of genera <em>Amritotus, Busoniomimus </em>and <em>Jogocerus</em> were described with their distribution in the country. <em>Busoniomimus manjunathi</em> Viraktamath and Viraktamath and <em>Jogocerus freytagi</em>were described for the first time from Sri Lanka.

Structural features of the mitogenome of the leafhopper genus Cladolidia (Hemiptera: Cicadellidae: Coelidiinae) and phylogenetic implications in Cicadellidae.

The first two complete mitogenomes of the leafhopper genus Cladolidia (C. biungulata and C. robusta) were sequenced and annotated to further explore the phylogeny of Cladolidia. Both the newly sequenced mitogenomes have a typical circular structure, with lengths of 15,247 and 15,376 bp and A + T contents of 78.2% and 78%, respectively. We identified a highly conserved genome organization in the two Cladolidia spp. through comparative analysis that included the following assessments: genome content, gene order, nucleotide composition, codon usage, amino acid composition, and tRNA secondary structure. Moreover, we detected the base heterogeneity of Cicadellidae mitogenomic data and constructed phylogenetic trees using the nucleotide alignments of 12 subfamilies of 58 leafhopper species. We noted a weak heterogeneity in the base composition among the Cicadellidae mitogenomes. Phylogenetic analyses showed that the monophyly of each subfamily was generally well supported in the family Cicadellidae; the main topology was as follows: (Deltocephalinae + (Treehoppers + ((Megophthalminae + (Macropsinae + (Hylicinae + (Coelidiinae +Iassinae)) + (Idiocerinae + (Cicadellinae + (Typhlocybinae + (Mileewinae + (Evacanthinae +Ledrinae)))))))))). Within Coelidiinae, phylogenetic analyses revealed that C. biungulata and C. robusta belong to Coelidiinae and the monophyly of Cladolidia is well supported. In addition, on the basis of complete mitogenome phylogenetic analysis and the comparison of morphological characteristics, we further confirm the genus Olidiana as a paraphyletic group, suggesting that the genus may need taxonomic revisions.

A new species of bamboo-feeding leafhopper genus Myittana from India (Hemiptera: Cicadellidae).

A new bamboo leafhopper species, Myittana (Myittana) bidentata sp. nov. is described and illustrated from India (Pantnagar, Uttarakhand). The new species is similar to Myittana (Myittana) distincta but can be distinguished by its large size (7.8 mm long) and the male genital structure. An annotated species checklist of the genus and key to species of the subgenus Myittana (Myittana) are also provided.

Mating Communication of the Variegated Leafhopper, Erasmoneura variabilis, With Notes on Vibrational Signaling of Other Grapevine Cicadellids in California

Abstract Leafhoppers in the tribe Erythroneurini are a concern for grape growers in California due to direct feeding damage by piercing the leaves. Management of leafhopper populations in vineyards may be accomplished by insecticide applications, the release of natural enemies, conservation biological control, exploitation of controlled deficit irrigation, or a combination of the above. Based on research on other leafhopper species, a behavioral mating disruption is a viable option, but nothing is known about the mating communication and circadian signaling of these species in vineyards. The objectives of this study were to identify and describe vibrational signals associated with mate selection behavior of Erasmoneura variabilis and Erythroneura ziczac, and evaluate the occurrence of vibrational signals within sympatric populations of E. variabilis, E. ziczac, and Homalodisca vitripennis on grapevines. Analysis of vibrational communication signals revealed that 1) one female signal and two distinct male signals are used in E. variabilis pair formation, 2) the pair formation process in E. variabilis is divided into three communication phases, 3) E. variabilis pre-copulatory communication is longer in the presence than in the absence of male-male rivalry, 4) two distinct signals are used in E. ziczac pair formation, and 5) E. variabilis, E. ziczac, and H. vitripennis sing at night and during the day. Results include detailed descriptions of leafhopper communication signals that are relevant for future development of vibrational disruption as a novel method to suppress populations under field conditions.

First records of the North American leafhopper Gyponana mail (Hemiptera: Cicadellidae) invading urban gardens and agroecosystems in Europe

The Nearctic leafhopper species Gyponana (Gyponana) mali DeLong, 1942 is reported from Europe for the fi rst time and represents the fi rst record of the tribe Gyponini Stål, 1870 (Hemiptera: Cicadellidae: Iassinae: Gyponini) for the Palearctic Region. Specimens were collected in southern Switzerland (Ticino) and two regions of northern Italy (Lombardy and Veneto) in 2015–2019. The preferred host plant in these areas appears to be Cornus sanguinea L. Phylogenetic analysis of the COI barcode sequences grouped one of the European specimens with three individuals of G. (G.) mali from Ontario, Canada. Morphological study indicated that the male genitalia of the European population are intermediate between G. (G.) mali and G. (G.) extenda DeLong, 1942.

A FIVE-YEAR SURVEY IN TUSCANY (ITALY) AND DETECTION OF XYLELLA FASTIDIOSASUBSPECIES MULTIPLEXIN POTENTIAL INSECT VECTORS, COLLECTED IN MONTE ARGENTARIO

The vector‐borne bacterium Xylella fastidiosa(Wells and Raju) causes several serious diseases to plants. Recently, different subspecies of X. fastidiosa were reported in some European countries. The risk of the bacterium’s spread on the entire European territory is very high; therefore, it has been added into the priority pest list (2019/1702/EU Regulation). The main purposes of this work were to verify the presence of potential vectors in areas at a high risk of introduction in Tuscany and to ascertain the presence of X. fastidiosa in these insect vectors. Over 4,000 Auchenorrhyncha were collected and analysed from 2015 to 2019. Among the xylem sap-feeder putative vectors, most of the insects collected belonged to the family Aphrophoridae, but also many species of leafhopper were identified. Overall, in Tuscany four species were the most represented: Philaenus spumarius(L.), Cicadella viridis(L.), Synophropsis lauri (Horvath) and Neophilaenus campestris(Fallen).In 2018 an outbreak of X. fastidiosa subsp. multiplex was reported in Monte Argentario (Grosseto province, Tuscany). In 2019 X. fastidiosa subspecies multiplex ST 87 was detected in seven P. spumarius and three N. campestris collected from the infected area.

LABORATORY AND FIELD STUDIES FOR DETERMINATION OF SPRAYING POTASSIUM SULFATE AGAINST GREEN BUG Nezara viridula (L.) AND LEAF HOPPER Empoasca discipiens (PAOLI) INFESTED TOMATO CROP.

Two different experiments were carried out to evaluate the toxicity and insecticidal activity of the fertilizer, potassium sulfate against two species of green bug Nezara virdula, and leafhopper Empoasca discipiens (Paoli) infesting tomato plant. The first experiment was done in the laboratory to determine the toxicity of the tested material by spraying different concentration on tomato seedling in pots artificially infested with leafhopper and green bug while the second one was done in field to determine the insecticidal activity against leafhopper and green bug besides the phytotoxicity of potassium sulfate when sprayed at concentrations 0.25, 0.5 and 0.75% on tomato crop. Results obtained indicated that potassium sulfate showed high toxic effect against the two species of leaf hopper and green bug since LC5owere 8.9 and 8.6 ppm on green bug and leafhopper respectively, while the second experiment indicated that concentration 0.5% was suitable for controlling the two species of insect leaf hopper and green bug without any phytotoxic effect on tomato plant.

Seasonal phenology and damage by Singapora shinshana (Hemiptera: Cicadellidae) and other leafhoppers on ornamental trees in Korea

AbstractSingapora shinshana is a leafhopper native to mid‐Asia with a specific host range and is one of the least studied species within the genus. Recently, the species has been found to cause significant damage to host plants including ornamental trees, normally inflicted by its sucking behavior. This study uncovered more details on host and season preference of S. shinshana, damage potential and symptoms caused by its feeding behavior on ornamental trees in Korea, in addition to other records of other leafhoppers of economic importance. During the sticky trap survey period from 2017 to 2019, 12 leafhopper species were recovered from the eight selected ornamental tree species. Singapora shinshana was the most dominant species, constituting 94.8% of the total collected leafhopper population; with its highest incidence observed on Prunus serrulata, followed by Elaeagnus umbellata and Pseudocydonia sinensis. The high abundance on P. serrulata correlated with high damaged leaf percentages of 94.2%, 95.2%, and 98.1% in October 2017, 2018, and 2019, respectively. Interestingly, in terms of damaged leaf percentage, Rosa hybrida and Zelkova serrata were the second and third most damaged hosts despite the significantly lower population of the leafhopper on these trees. Furthermore, S. shinshana counts increased from late‐July to late‐September, with the peak evident during early August. Prunus serrulata can therefore be taken as one of the main host plants of S. shinshana. However, the potential of the host to suffer damage is not limited to population densities of the pest alone but also susceptibility and tolerance of the host plant.

A new genus and species of Mileewini leafhoppers (Hemiptera, Cicadellidae, Mileewinae) from China, with a key to genera.

A new leafhopper genus and species, Anzihelus bistriatus Yan & Yang, gen. nov. sp. nov. (Cicadellidae, Mileewinae, Mileewini) is described from Sichuan Province, China. Habitus images and figures of the male and female genitalia are provided together with a key to the genera of Mileewini from China.

Histological and quantitative image analyses of rice gall formed by orange leafhopper Cicadulina bipunctata (Hemiptera: Cicadellidae)

The orange leafhopper, Cicadulina bipunctata (Melichar) (Hemiptera: Cicadellidae), is an insect pest of various Poaceae plants. Feeding by this leafhopper species induces growth suppression and gall formation, which is characterized by severe swelling of leaf veins, named wallaby ear symptoms. In this study, we performed histological analysis of the cell differentiation in the galled leaves of rice seedlings and devised a new method to quantify the degree of gall formation. In the histological study, abnormal vascular cell patterning and differentiation were observed in the galled leaves. Morphological changes during gall formation were quantitatively evaluated through image analysis.

Identification of Phytoplasmas Representing Multiple New Genetic Lineages from Phloem-Feeding Leafhoppers Highlights the Diversity of Phytoplasmas and Their Potential Vectors.

Phytoplasmas are obligate transkingdom bacterial parasites that infect a variety of plant species and replicate in phloem-feeding insects in the order Hemiptera, mainly leafhoppers (Cicadellidae). The insect capacity in acquisition, transmission, survival, and host range directly determines the epidemiology of phytoplasmas. However, due to the difficulty of insect sampling and the lack of follow-up transmission trials, the confirmed phytoplasma insect hosts are still limited compared with the identified plant hosts. Recently, quantitative polymerase chain reaction (qPCR)-based quick screening of 227 leafhoppers collected in natural habitats unveiled the presence of previously unknown phytoplasmas in six samples. In the present study, 76 leafhoppers, including the six prescreened positive samples, were further examined to identify and characterize the phytoplasma strains by semi-nested PCR. A total of ten phytoplasma strains were identified in leafhoppers from four countries including South Africa, Kyrgyzstan, Australia, and China. Based on virtual restriction fragment length polymorphism (RFLP) analysis, these ten phytoplasma strains were classified into four distinct ribosomal (16Sr) groups (16SrI, 16SrIII, 16SrXIV, and 16SrXV), representing five new subgroups (16SrI-AO, 16SrXIV-D, 16SrXIV-E, 16SrXIV-F, and 16SrXV-C). The results strongly suggest that the newly identified phytoplasma strains not only represent new genetic subgroup lineages, but also extend previously undiscovered geographical distributions. In addition, ten phytoplasma-harboring leafhoppers belonged to seven known leafhopper species, none of which were previously reported insect vectors of phytoplasmas. The findings from this study provide fresh insight into genetic diversity, geographical distribution, and insect host range of phytoplasmas. Further transmission trials and screening of new potential host plants and weed reservoirs in areas adjacent to collection sites of phytoplasma harboring leafhoppers will contribute to a better understanding of phytoplasma transmission and epidemiology.

Biogeographical evaluation and conservation assessment of arboreal leafhoppers in the Mexican Transition Zone biodiversity hotspot

AbstractAimsMexico harbours a diverse fauna comprising more than 1,400 leafhopper species, 60% of which appear to be strictly endemic, with many apparently restricted to particular habitats and host plants. The aims of this study were to identify areas of high species richness and endemism, and determine the biogeographic affinities of species in the diverse arboreal tribe Athysanini to provide data useful for conservation prioritization.LocationMexico.MethodsA data set of 643 historical occurrence records based on authoritatively identified specimens from museums, recent fieldwork, literature and digital repositories was analysed. Analyses of species richness and areas of endemism were conducted using geographic information systems.ResultsA total of 164 species belonging of 50 genera were included, of which 145 species of 31 genera are considered to be endemic. The Mexican state of Guerrero yielded the most species records (48%). The highest numbers of taxa and endemic species were concentrated along the Mexican Transition Zone (MTZ) within which the Trans‐Mexican Volcanic Belt (TVB) province had the most species records. Endemicity analyses showed two different geographical patterns but similar species richness weights with overlapping values over the MTZ. Distribution across vegetation types was not uniform, with most athysanine species concentrated in the dry tropical forest (65%). Species were documented at elevations between sea level and 3,200 m a.s.l. with three altitudinal preference classes. Conservation assessments applying IUCN criteria categorized a majority of species (145) as endangered or critically endangered.Main conclusionsOur findings suggest that most identified areas of high species richness throughout the territory have predominantly endemic taxa. Distributional patterns found are non‐random, influenced by richness and endemism values over the TVB province and in the MTZ with a variable dispersion among species. Data highlight a greatly threatened status by habitat loss, remarking an urgent need for an improved conservation framework.