Search Results (155)

This review explores the evolving role of the tea green leafhopper, Empoasca onukii, in the tea industry, transitioning from a recognized pest to a significant enhancer of tea quality. Recent research highlights how its feeding behavior stimulates the production of desirable secondary metabolites, thereby improving the flavor profiles and market value of premium teas, particularly varieties like Taiwan’s “Oriental Beauty”. As consumer demand for unique and artisanal teas rises, the economic benefits associated with E. onukii are becoming increasingly evident, prompting farmers to adopt sustainable agricultural practices that often involve reduced pesticide use. Furthermore, the dynamic interplay between climatic factors, E. onukii population dynamics, and tea cultivation practices necessitates integrated pest management strategies that balance the beneficial and detrimental impacts of this leafhopper. Understanding these complexities not only fosters sustainable production methods but also opens niche markets, benefiting local economies and promoting both economic viability and environmental sustainability in the tea industry. Full article

Tambocerus elongatus (Shen) (Hemiptera: Cicadellidae) is a devastating insect pest species of Camellia sinensis, significantly affecting the yield and quality of tea. Due to growing concerns over the irrational use of insecticides and associated food safety, it is crucial to better understand the innate resistance mechanism of tea trees to T. elongatus. This study aims to explore the responses of tea trees to different levels of T. elongatus infestation. We first focused on the primary metabolism and found that the amino acid levels decreased significantly with increasing T. elongatus infestation, while sugar accumulation showed an opposite trend. Moreover, secondary metabolite analysis showed a significant increase in flavonoid compounds and lignin content after T. elongatus infestation. Metabolomics analysis of the flavonoid compounds revealed a decrease in the proanthocyanidin level and an increase in anthocyanidin glycosides (anthocyanins and their derivatives) after T. elongatus infestation. T. elongatus infestation also caused a decrease in the abundance of non-ester catechins and an increase in the abundance of ester catechins. Furthermore, the gene expression analysis revealed that transcripts of genes involved in flavonoid biosynthesis, such as CsCHI, CsF3H, CsF3′H, CsFNS, CsFLS, and CsUFGT, were down-regulated, while genes involved in the lignin pathway were up-regulated by insect infestation, suggesting that lignin probably plays a pivotal role in tea plant response to T. elongatus infestation. Analysis of the expression of related genes indicates that the jasmonate (JA) pathway primarily responds to leafhopper damage. These findings suggest that the lignin pathway and JA play a preferential role in tea plant response to T. elongatus. Furthermore, the production of saccharides and the accumulation of anthocyanin glycosides in the flavonoid metabolic pathway are critical during this stress response. Further exploration of the roles of anthocyanin glycosides and lignin in tea tree resistance could provide a theoretical basis for understanding the defense mechanism of tea trees against T. elongatus damage. Full article

Phytoplasmas are a group of plant-pathogenic, cell-wall-less bacteria vectored primarily by leafhoppers (Hemiptera Cicadellidae), one of the most diverse families of insects. Despite the importance of documenting associations between phytoplasmas, their insect vectors, and plant hosts to prevent disease outbreaks, such knowledge is currently highly incomplete and largely neglects the diversity of the system in natural areas. Here, we used anchored hybrid enrichment (AHE) to recover the DNA of five plant genes (rbcL, matK, ITS1, ITS2, and trnH-psbA) in 58 phloem-feeding leafhoppers from around the world that had previously tested positive for phytoplasma infection. Using BLASTn and a strict filtering approach, we assigned taxonomic classifications to the plant sequences and tested for cophylogenetic signals between potential Deltocephalinae leafhopper vectors and their associated plants. We observed incongruence between plant and insect phylogenies. Many leafhopper species, including presumed grass specialists, fed on distantly related plant lineages; 66% of sampled leafhoppers fed on plants from at least two different orders. By disentangling phytoplasma–leafhopper–plant interactions, we identify locations at risk of phytoplasma disease outbreaks. Furthermore, the observed wide diet breadth raises questions about how phytoplasma infection may manipulate the feeding preference of their insect host and helps fill the gaps in understanding the ecology and diversification of the tripartite association. Full article

A three-year study in two Mediterranean peach orchards monitored Auchenorrhyncha species, including the main vectors of plant pathogens causing significant economic losses. The research focused on the management of two polyphagous leafhoppers, Asymmetrasca decedens and Hebata (Signatasca) solani. Yellow sticky traps were used to track species dynamics and assess population trends in relation to meteorological factors such as temperature, rainfall, and humidity. Chemical treatments and early green pruning were evaluated for pest control effectiveness. Fifty-five Auchenorrhyncha species were identified, including vectors of Xylella fastidiosa. H. solani appeared from spring to early summer, and was gradually replaced by A. decedens, which peaked in late summer. Higher temperatures favoured A. decedens, while rainy days significantly reduced its presence. H. solani responded less consistently to meteorological factors, but increased with higher minimum relative humidity, and decreased with higher total humidity. These results highlight the need for targeted chemical control strategies to manage A. decedens during its peak season and the benefits of early green pruning to protect susceptible trees in spring. The results emphasise the role of climate in pest dynamics and provide important insights for IPM programmes to reduce economic losses in Mediterranean peach orchards worldwide. Full article

One of the main obstacles in rice cultivation is tungro disease, caused by Rice Tungro Spherical Virus (RTSV) and Rice Tungro Bacilliform Virus (RTBV), which are transmitted by green leafhopper vectors (Nephotettix virescens). This disease can be controlled by using pesticides and refugia plants. Excessive use of pesticides can have negative impacts and high costs, so it is necessary to control the use of pesticides. In this study, a mathematical model of the spread of tungro virus disease in rice plants was developed by considering the characteristics of the virus, the presence of green leafhoppers and natural enemies, refugia planting, and pesticide use. From this model, dynamic and sensitivity analyses were carried out, and the optimal control theory was searched using the Pontryagin minimum principle. The analysis results showed three equilibriums: two non-endemic equilibriums (when plant and vector populations exist and when plant, vector, and natural enemy populations exist) and one endemic equilibrium. The non-endemic equilibrium will be asymptotically stable locally if $R_0<1$. At the same time, the parameters that greatly influence the spread of this disease are parameters $\mu , {\mu }_2$, and $\varphi$ for local sensitivity analysis and $\alpha , a, \beta , b, \varphi ,$ and ${\mu }_2$ for global sensitivity analysis. The results of the numerical simulation show that control using combined control is more effective in reducing the intensity of the spread of tungro disease in rice plants than control in the form of planting refugia plants as a source of food for natural enemies. The use of pesticides is sufficient for only four days, so the costs incurred are quite effective in controlling the spread of this disease. Full article

In Uganda, the common bean (Phaseolus vulgaris) is often infested by a complex of insect pests, but bean flies, aphids, bean leaf beetles, and flower thrips are the most important. Whereas yield losses due to these pests have been established, there is limited information on their population dynamics at different stages of crop growth and their effect on yield and yield components. In order to describe the population dynamics of selected common bean pests at various phases of bean crop growth, and their impact on yield and yield components, a study was carried out in Uganda during the 2016 second rains and the 2017 first rains in three agro-ecological zones. Bean flies, bean aphids, bean leaf beetles, whitefly, striped bean weevil, leafhoppers, and caterpillars were the main insects observed. Pesticide spray schedules were imposed to generate different populations of insect pests whose effects on yield and its components were determined. The findings indicate that spray regimes significantly influenced the abundance of bean flies and leafhoppers, but not the other insect pests. Additionally, except for caterpillars, insect pests were significantly influenced by crop growth stages, but only leafhoppers exhibited a significant negative relationship with grain yield. Furthermore, yield and yield components varied significantly between spray regimes, and there was a significant positive relationship between grain yield and yield components. Our study is important for informing growers on the stage of crop growth at which management tactics such as use of insecticides can be applied for different insect pests. Full article

This is the first study to assess the physicochemical and biological compatibility of herbicides used in corn crops with entomopathogenic fungi used in the management of Dalbulus maidis in Brazil. The biological index was employed to ascertain the in vitro compatibility of the herbicides with pure spores (not formulated) of tested fungal isolates (Esalq-1296 of Cordyceps javanica and IBCB66 and Simbi BB15 of Beauveria bassiana). The results indicated a significant interaction between herbicides and fungal isolates when colony diameter and colony-forming units (CFU) were considered. Furthermore, changes in physicochemical characteristics were observed in some mixtures of herbicides and mycoinsecticides tested. The number of CFU was significantly reduced as the exposure time increased in the mixtures containing all the herbicides tested. In general, the Esalq-1296 isolate of C. javanica, formulated in a suspension concentrate (Octane^®), proved to be more sensitive to the herbicides studied. In vivo bioassays demonstrated that, despite the synergistic effect of the binary mixtures of herbicides and mycoinsecticides on D. maidis mortality, the presence of the herbicide in the mixtures prevented the extrusion of entomopathogens from cadavers; therefore, caution is recommended when combining mycoinsecticides and post-emergent herbicides in tank mixtures aiming to manage D. maidis. Full article

Okra (Abelmoschus esculentus) is an important agricultural crop of the Malvaceae family, cultivated across tropical, subtropical, and warm temperate regions. However, okra production faces numerous challenges from diverse pest species, including insects, nematodes, arachnids, and mites, that significantly reduce its yield. Major economic pests include the cotton aphid, cotton spotted bollworm, Egyptian bollworm, cotton mealybug, whitefly, cotton leafhopper, cotton bollworm, two-spotted spider mite, root-knot nematode, reniform nematode, cotton leaf roller, and flea beetle. Additionally, less prevalent pests such as the blister beetle, okra stem fly, red cotton bug, cotton seed bug, cotton looper, onion thrips, green plant bug, and lesion nematode are also described. This review also addresses fungal and oomycete diseases that present high risks to okra production, including damping-off, powdery mildew, Cercospora leaf spot, gray mold, Alternaria leaf spot and pod rot, Phyllosticta leaf spot, Fusarium wilt, Verticillium wilt, collar rot, stem canker, anthracnose, and fruit rot. In addition to these fungal diseases, okra is also severely affected by several viral diseases, with the most important being okra yellow vein mosaic disease, okra enation leaf curl disease, and okra mosaic disease, which can cause significant yield losses. Moreover, okra may also suffer from bacterial diseases, with bacterial leaf spot and blight, caused primarily by Pseudomonas syringae, being the most significant. This manuscript synthesizes the current knowledge on these pests. It outlines various management techniques and strategies to expand the knowledge base of farmers and researchers, highlighting the key role of integrated pest management (IPM). Full article

The study of Auchenorrhyncha species composition in Greek olive orchards is crucial due to the potential threat of Xylella fastidiosa invading the region. Recent studies have begun exploring agricultural landscapes, particularly olive and citrus orchards. From 2016 to 2022, biodiversity surveys were conducted in thirteen olive orchards across three regions of Greece: Peloponnese, Sterea Ellada, and the Northeast Aegean. Malaise traps were installed in each orchard and monitored monthly, supplemented by sweep net sampling in two orchards to capture less mobile species and assess their association with host plants. A total of 14,771 specimens were collected, representing 125 species predominantly feeding on weeds. The dominant species were the Typhlocybinae Hebata decipiens and Zyginidia pullula, while Euscelis lineolata was the most common Deltocephalinae. Aphrophoridae, including Philaenus spumarius and Neophilaenus campestris, were more effectively collected with sweep nets, primarily from Avena sterilis L. This study offers a detailed overview of the Auchenorrhyncha fauna in Greek olive orchards, providing essential insights for developing strategies to prevent the invasion of Xylella fastidiosa. Full article

Batkoa is a genus of entomophthoralean fungi often associated with insect epizootics, particularly in phytophagous hemipterans. Encapsulation has become a promising strategy for improving the shelf life and sporulation of these fungi post-application. This study aims to (i) compare the virulence of the submerged propagules and primary conidia of Batkoa sp. ESALQ1199 against Dalbulus maidis; (ii) formulate submerged propagules in calcium alginate beads with co-formulants; (iii) assess the colony-forming units and sporulation of encapsulated beads dried with different kaolin concentrations (0%, 2%, 4%, 8% and 10%); (iv) determine the shelf life of dried bead formulations containing 10% kaolin, comparing washed and unwashed beads treated with a 4% sucrose solution; and (v) assess the sporulation capacity of beads with 10% kaolin, washed and unwashed with 4% sucrose solution, over time under humid conditions. Our results demonstrated that primary conidia and submerged propagules effectively killed 82.4% and 57.8% of adult corn leafhoppers, respectively. Co-formulants maintained viability above 80% in dried propagules, while control samples dropped to 45%, indicating the sensitivity of submerged propagules to the drying process. Encapsulated Batkoa sp. retained the same concentration of viable propagules per bead and the number of conidia produced (sporulation) for 30 days at 28 °C. The sporulation of fresh beads increased during the incubation period, plateauing after 27 days. This suggests that Batkoa sp. beads can produce primary conidia under humid field conditions, serving as a potential inoculum source for new infections. Full article

The pine leafhopper genus Pinopona Viraktamath & Sohi was previously classified within the tribe Grypotini. In a recognized classification system, it has been categorized as the subtribe Grypotina of the tribe Koebeliini within Deltocephalinae, based on morphological characteristics such as a crown exhibiting few transverse fine striations along the anterior margin; short antennae measuring less than 1.5 times the head length but not extending to half or more of body length; ocelli positioned below the anterior margin of the crown and not visible from above, with a considerable distance from the eyes; and an anteclypeus that is narrow and tapered beyond the anterior margin of gena, alongside metatarsomere I presenting platellae on the plantar surface. Two new species, Pinopona gongshanensis and Pinopona daliensis spp. nov., are described herein from Yunnan Province and illustrated accordingly. This study also provides a checklist and key for all species within this genus. Full article

The Nearctic leafhopper Scaphoideus titanus (Hemiptera: Cicadellidae) is the primary vector of ‘Candidatus Phytoplasma vitis’, the causative agent of Flavescence doreé in Europe. Although microorganisms play an important role in the ecology and behavior of insects, knowledge about the interaction between S. titanus and microbes is limited. In this study, we employed an amplicon metabarcoding approach for profiling the V4 region of the 16S rRNA gene to characterize the bacterial communities of S. titanus across several populations from four European localities. Additionally, we investigated changes in bacterial communities between nymphal and adult stages. In total, we identified 7,472 amplicon sequence variants (ASVs) in adults from the European populations. At the genus level, ‘Candidatus Karelsulcia’ and ‘Candidatus Cardinium’ were the most abundant genera, with both being present in every individual. While we found significant changes in the microbial composition of S. titanus across different European populations, no significant differences were observed between nymphal and adult stages. Our study reveals new insights into the microbial composition of S. titanus and highlights the role of geography in influencing its bacterial community. Full article

The maize leafhopper (Dalbulus maidis) is a significant threat to maize crops in tropical and subtropical regions, causing extensive economic losses. While its ecological interactions and control strategies are well studied, its associated viral diversity remains largely unexplored. Here, we employ high-throughput sequencing data mining to comprehensively characterize the D. maidis RNA virome, revealing novel and diverse RNA viruses. We characterized six new viral members belonging to distinct families, with evolutionary cues of beny-like viruses (Benyviridae), bunya-like viruses (Bunyaviridae) iflaviruses (Iflaviridae), orthomyxo-like viruses (Orthomyxoviridae), and rhabdoviruses (Rhabdoviridae). Phylogenetic analysis of the iflaviruses places them within the genus Iflavirus in affinity with other leafhopper-associated iflaviruses. The five-segmented and highly divergent orthomyxo-like virus showed a relationship with other insect associated orthomyxo-like viruses. The rhabdo virus is related to a leafhopper-associated rhabdo-like virus. Furthermore, the beny-like virus belonged to a cluster of insect-associated beny-like viruses, while the bi-segmented bunya-like virus was related with other bi-segmented insect-associated bunya-like viruses. These results highlight the existence of a complex virome linked to D. maidis and paves the way for future studies investigating the ecological roles, evolutionary dynamics, and potential biocontrol applications of these viruses on the D. maidis—maize pathosystem. Full article

The corn leafhopper, Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae), is an invasive insect that can cause damage to maize (Zea mays L.) in two ways: by direct feeding and the transmission of several plant pathogens. Dalbulus maidis is an invasive and serious economic pest of maize that has spread from its center of origin in Mexico to the southernmost parts of the United States. Prior to 2024, corn leafhoppers had not been documented in Oklahoma, and their spread northward toward the United States corn belt is of significant concern. Here, we provide the first reports of the insect in maize in several Oklahoma counties. Insect specimens were collected at various commercial and experimental field sites by Oklahoma State University research and extension personnel. The identity of the insect species was validated through morphological and molecular taxonomy. The presence records for the corn leafhopper presented here provide valuable information for future monitoring and management efforts of this economically important pest and disease. Full article

Balclutha incisa (Cicadellidae: Deltocephalinae), a leafhopper prevalent in tropical and temperate regions, is notably abundant in grasses and rice. The virome of B. incisa was investigated using deep transcriptome sequencing, leading to the first identification of four viruses belonging to the families Aliusviridae, Iflaviridae, and Totiviridae in B. incisa. These viruses have been provisionally named B. incisa ollusvirus 1 (BiOV1), B. incisa ollusvirus 2 (BiOV2), B. incisa iflavirus 1 (BiIV1), and B. incisa totivirus 1 (BiTV1). The complete genome sequences of these viruses were obtained through rapid amplification of cDNA ends (RACE). BiOV1 has a linear genome of 15,125 nucleotides (nt), while BiOV2 possesses a circular genome of 14,853 nt. The BiIV1 genome, excluding the poly(A) tail, is 10,903 nt in length and encodes a single open reading frame (ORF) for a polyprotein consisting of 3194 amino acids (aa). The BiTV1 genome is 4357 nt long and contains two overlapping ORFs, with the viral RNA-dependent RNA polymerase (RdRp) translated via a −1 ribosomal frameshift. Phylogenetic and sequence identity analyses suggest that all these viruses are novel members of their respective families. This study significantly expands our understanding of the virome associated with B. incisa by reporting and characterizing these novel viruses. Full article