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β-N-Acetylglucosaminidases and/or β-N-acetylhexosaminidases (NAGs / Hexes) are crucial exonucleases, playing a crucial role in the insect molting process. SfHex3 and SfHex4 contain conserved catalytic domains of GH20 and GH20b, clustered into NAG2 and NAG1 group, respectively. SfHex3 and SfHex4 were mainly highly expressed in the 4th-5th instar nymphs, as well as in the integument and ovary. The expression level of SfHex3 gradually decreased in male and female adults, and SfHex4 on the first day of female was significantly higher than that on the first day of male. In addition, RNA interference (RNAi) results demonstrated that the downregulation of SfHex3 and SfHex4 expression in 5th-instar nymphs resulted in failed molting, and a high mortality. Furthermore, after RNAi with SfHex3 and SfHex4, the transcript levels on key genes of the chitin metabolism pathway (SfCHS1, SfCHS1a, SfCHS1b, SfTRE1, SfTRE2, SfCht5, and SfCht7) were significantly decreased compared to the control group. Meanwhile the expression levels of SfHex3 and SfHex4 were up-regulated after 6 h and 12 h of 20E treatment. And the transcription levels of SfHex3 and SfHex4 were significantly inhibited at nitenpyram LC 20 , LC 50 , and LC 90 after 96 h of treatment, in 3rd nymphs of Sogatella furcifera. In conclusion, SfHex3 and SfHex4 play important roles in the nymphal development of S. furcifera, contributing to the molting process from nymph to adult. This study not only enhances our understanding of the nitenpyram in pest control, but also provides a foundation for the development of new control strategies using RNAi to targeting SfHex3 and SfHex4., Competing Interests: Declaration of competing interest The authors declare no conflict of interest. The authors alone are responsible for the content and writing of the paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

A new leafhopper genus Sugea gen. nov. is described and illustrated here based on type species Sugea obtusangula sp. nov. from Yunnan Province, China, and placed in the tribe Dikraneurini (subfamily Typhlocybinae). Sugea is easily distinguishable from all other known dikraneurine genera based on the angulate face profile with a distinct submarginal furrow present along the anterior and lateral margins.

Akt (also known as protein kinase B) belongs to the multifunctional serine/threonine kinase family and is an important component of the insulin signaling pathway that plays a key role in many biological processes such as cell growth, proliferation, and survival. However, few studies have reported the effect of Akt on reproduction in Hemiptera. In this study, we cloned and characterized the Akt gene from Coridius chinensis (CcAkt). The open reading frame of CcAkt has a length of 1,563 bp and encodes 520 amino acids. It has a conserved pleckstrin homology domain (PH), catalytic domain of serine/threonine protein kinases (S_TKc), and extension of Ser/Thr-type protein kinases (S_TK_X). Phylogenetic analysis showed that CcAkt and HhAkt of Halyomorpha halys had the highest similarity. Analysis of temporal and spatial expression patterns revealed that CcAkt is expressed throughout development and in various tissues of C. chinensis adults. CcAkt was highly expressed in the female adult and the fourth-instar nymph, as well as in the testis and ovary of C. chinensis. Injection of bovine insulin and methoprene induced the CcAkt expression, whereas that of 20-hydroxyecdysone significantly reduced the CcAkt expression. These three hormones, however, induced the expression of vitellogenin (Vg) and vitellogenin receptor (VgR). In unmated females, knockdown of CcAkt resulted in decreased expression of CcVg and CcVgR, stunted the development of the ovarioles, decreased the number of eggs and hatching rate. These findings from RNA interference experiment suggested that CcAkt may be involved in regulating the reproduction of C. chinensis., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

To elucidate phylogenetic relationships within the leafhopper's subfamily Megophthalminae (Hemiptera: Cicadellidae), mitogenomes of 12 species of the subfamily were sequenced and assembled. These were added to the mitogenomes of the eight other species that are currently available. Mitogenome size ranged from 15,193 bp in Onukigallia onukii (Matsumura, 1912) to 15,986 bp in Multinervis guangxiensis (Li and Li, 2013), they all contained 37 genes, and gene order was similar to that in other leafhoppers. Nucleotide composition analysis showed that the AT content was higher than that of GC, and the protein-coding genes usually ended with A/T at the 3rd codon position. The Ka/Ks ratio showed that the CYTB gene has the slowest evolutionary rate, while ND4 is the gene with the fastest evolutionary rate. Relative synonymous codon usage analysis revealed the most frequently used codon was UUA (L), followed by CGA (R), and the least frequently used codon was CCG (P). Parity plot and neutrality plot analyses showed that the codon usage bias of mitochondrial genes was influenced by natural selection and mutation pressure. However, natural selection plays a major role, while the effect of mutation pressure was small. Effective number of codons values were 40.15-49.17, which represented relatively low codon bias. Phylogenetic analyses based on three datasets (AA, 13PCG, 13PCG_2rRNA) using two methods (maximum likelihood and Bayesian inference). In the obtained topology, the Megophthalminae species were clustered into a monophyletic group. In conclusion, our results clarify structural modules of the mitochondrial genes and confirm the monophyly of Megophthalminae within Cicadellidae., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America.)

Batracomorphus is the most diverse and widely distributed genus of Iassinae. Nevertheless, there has been no systematic analysis of the genome structure and phylogenetic relationships of the genus. To determine the characteristics of the mitogenomes of Batracomorphus species as well as the phylogenetic relationships between them, we sequenced and compared the mitogenomes of 11 representative Batracomorphus species. The results revealed that the mitogenomes of the 11 Batracomorphus species exhibited highly similar gene and nucleotide composition, and codon usage compared with other reported mitogenomes of Iassinae. Of these 11 species, we found that the mitogenomes of four species were rearranged in the region from trnI - trnQ - trnM to trnQ - trnI - trnM , whereas the remaining species presented a typical gene order. The topologies of six phylogenetic trees were in agreement. Eurymelinae consistently formed paraphyletic groups. Ledrinae and Evacanthinae formed sister taxa within the same clade. Similarly, Typhlocybinae and Mileewinae consistently clustered together. All phylogenetic trees supported the monophyly of Iassinae, indicating its evolutionary distinctiveness while also revealing its sister relationship with Coelidiinae. Notably, the nodes for all species of the genus Batracomorphus were well supported and these taxa clustered into a large branch that indicated monophyly. Within this large branch, four Batracomorphus species with a gene rearrangement ( trnQ - trnI - trnM ) exhibited distinctive clustering, which divided the large branch into three minor branches. These findings expand our understanding of the taxonomy, evolution, genetics, and systematics of the genus Batracomorphus and broader Iassinae groups., Competing Interests: The authors declare they have no competing interests., (©2024 Lu et al.)

Although CRISPR/Cas9 has been widely used in insect gene editing, the need for the microinjection of preblastoderm embryos can preclude the technique being used in insect species with eggs that are small, have hard shells, and/or are difficult to collect and maintain outside of their normal environment. Such is the case with Sogatella furcifera, the white-backed planthopper (WBPH), a significant pest of Oryza sativa (rice) that oviposits inside rice stems. Egg extraction from the stem runs the risk of mechanical damage and hatching is heavily influenced by the micro-environment of the rice stem. To bypass these issues, we targeted embryos prior to oviposition via direct parental (DIPA)-CRISPR, in which Cas9 and single-guide RNAs (sgRNAs) for the WBPH eye pigment gene tryptophan 2,3-dioxygenase were injected into the hemocoel of adult females. Females at varying numbers of days posteclosion were evaluated to determine at what stage their oocyte might be most capable of taking up the gene-editing components. An evaluation of the offspring indicated that the highest G0 gene-edited efficacy (56.7%) occurred in females injected 2 d posteclosion, and that those mutations were heritably transmitted to the G1 generation. This study demonstrates the potential utility of DIPA-CRISPR for future gene-editing studies in non-model insect species and can facilitate the development of novel pest management applications., (© 2023 Institute of Zoology, Chinese Academy of Sciences.)

A new leafhopper species: Fistulatus motuoensis Hassan & Xing sp. nov. is described and illustrated from Xizang Autonomous Region, China. A key based on the aedeagus is given to distinguish all species of the genus. The type specimens of the new species are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC).

Two new leafhopper species, Longicornus concavus sp. nov. and Longicornus nonprocessus sp. nov., are described and illustrated from Tibet Autonomous Region, China. A key based on the aedeagus is given to distinguish all species of the genus. The type specimens of the new species are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC).

Two new species, Mukaria creagra Zhao, Luo & Chen sp. nov. and Mukaria striola Zhao, Luo & Chen sp. nov., of the bamboo-feeding leafhopper genus Mukaria Distant, 1908 are described and illustrated form Guizhou and Yunnan, China. Three species moved from Mukaria Distant, 1908 into Mukariella Viraktamath & Webb, 2019. A key for all known Chinese species of Mukaria and Mukariella is given.

The genus Bambuphaga Ramaiah, Meshram & Dey, 2023 is reported for the first time and a new species, Bambuphaga lanceata sp. nov. is described and illustrated from China. A key is given to distinguish all species of the genus. The type specimens of the new species are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC).

The brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae) (BPH), is a major, regionally migratory pest of rice in Asia. Despite intensive migratory studies, the seasonal migratory pattern of this species in the year-round breeding region (i.e., Hainan Island) remains largely unknown. To understand the migration dynamics, we conducted relevant research based on BPH light trap catches on Hainan in 2017-2022. Results showed that the occurrence dynamics of BPH in Hainan oscillated in different years and seasons. Overall, there are 4 migration peak periods on Hainan, with outbound peak periods in April-May and August-September and inbound peak periods in June and October. Trajectory and wind fields showed that in August-September, Hainan had complex meteorological conditions, and the outbound paths of BPH were variable, mainly landing in southeastern Guangxi and southwestern Guangdong. In contrast, April-May was influenced by southeasterly winds, with a wider outbound range and a further distance, landing along northeastern Vietnam from west to east toward Guangxi and Guangdong areas with time. Wind-rain fields, trajectory, and hydrogen isotope showed that in June, southwesterly winds transported BPH northward from the Indochina peninsula, where it was hindered by rainfall in the Leizhou Peninsula area and the migrants will be "rained out" into Hainan. Identically, in October, the interactions between northeasterly winds and rainfall belts on the southwest shore of Hainan increased the opportunities for BPH to migrate southward to reach Hainan. Our results suggest that Hainan is not only an important source of BPH migrating from East Asia but also plays the role of a bridge., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The mealybug genus Exilipedronia Williams, 1960 (Hemiptera: Coccomorpha: Pseudococcidae) is reported for the first time from Guizhou Province, China, based on a new species found infesting Bambusa sp. (Poaceae). It is described as Exilipedronia multipori Tan & Xing sp. n., and habitat photographs and illustrations are provided. The type material of E. multipori is deposited at the Institute of Entomology, Guizhou University, Guiyang, China (GUGC) and in the insect collection at the Department of Forestry Protection, Beijing Forestry University, Beijing, China (NFUC). A key to all three species of Exilipedronia is provided.

Vacuolar-type (H + )-ATPase (vATPase) is a conserved multi-subunit eukaryotic enzyme composed of 14 subunits that form a functional complex consisting of an ATP-hydrolytic domain (V1) and a proton-translocation domain (V0). ATP hydrolysis and subsequent H + translocation rely heavily on a fully assembled V1/V0 complex. Since vATPase is crucial for insect survival, it is a viable molecular target for pest control. However, detailed functional analyses of the 14 subunits and their suitability for pest control have not been fully explored in a single insect species. In this study, we identified 22 vATPase subunit transcripts that correspond to 13 subunits (A1, A2, B, C, D, E, F, G, H, a1, a2, c and d) in the white-backed planthopper (WBPH), Sogatella furcifera, a major hemipteran pest of rice. RNAi screens using microinjection and spray-based methods revealed that the SfVHA-F, SfVHA-a2 and SfVHA-c2 subunits are critical. Furthermore, star polymer (SPc) nanoparticles were utilized to conduct spray-induced and nanoparticle-delivered gene silencing (SI-NDGS) to evaluate the pest control efficacy of RNAi targeting the SfVHA-F, SfVHA-a2 and SfVHA-c2 transcripts. Target mRNA levels and vATPase enzymatic activity were both reduced. Honeydew excreta was likewise reduced in WBPH treated with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. To assess the environmental safety of the nanoparticle-wrapped dsRNAs, Cyrtorhinus lividipennis Reuter, a major natural enemy of planthoppers, was also sprayed with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. Post-spray effects of dsSfVHA-a2 and dsSfVHA-c2 on C. lividipennis were innocuous. This study identifies SfVHA-a2 and SfVHA-c2 as promising targets for biorational control of WBPH and lays the foundation for developing environment-friendly RNAi biopesticides., Competing Interests: Declaration of competing interest Peng He reports financial support was provided by Guizhou University. Peng He reports a relationship with Guizhou University that includes: employment. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Aspongopus chinensis Dallas, 1851 (Hemiptera: Dinidoridae), an edible and medicinal insect, usually found in China and Southeast Asia, offers substantial potential for various applications. The reproductive cycle of this particular insect occurs annually because of reproductive diapause, leading to inadequate utilization of available natural resources. Despite its considerable ecological importance, the precise mechanisms underlying diapause in A. chinensis are not yet well understood. In this study, we conducted an analysis of comparing the microRNA (miRNA) regulation in the diapause and non-diapause gonads of A. chinensis and identified 303 differentially expressed miRNAs, among which, compared with the diapause group, 76 miRNAs were upregulated and 227 miRNAs downregulated. The results, regarding the Enrichment analysis of miRNA-targeted genes, showed their involvement in several essential biological processes, such as lipid anabolism, energy metabolism, and gonadal growth. Interestingly, we observed that the ATP-binding cassette pathway is the only enriched pathway, demonstrating the capability of these targeted miRNAs to regulate the reproductive diapause of A. chinensis through the above essential pathway. The current study provided the role of gonadal miRNA expression in the control of reproductive diapause in A. chinensis, the specific regulatory mechanism behind this event remained unknown and needed more investigation., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America.)

A new genus of the tribe Scaphoideini from China, Paramelanetettix gen. nov. with P. expansivus sp. nov. as type species is described and illustrated. The type specimen of the new species is deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC).

The leafhopper genus Fistulatus Zhang, 1997 (Cicadellidae: Deltocephalinae: Drabescini: Paraboloponina) is reviewed with descriptions of two new species, Fistulatus biconjugara sp. nov., from Guizhou Province, China and F. brevimarginalis sp. nov., from Yunnan Province, China. A checklist with distributions and a key to males of this genus are provided. The specimens studied are deposited in the Institute of Entomology, Guizhou University, Guiyang, Guizhou, China (GUGC).

Satsumanus Ishihara is a small leafhopper genus in tribe Opsiini with six described species, and each have a very restricted biogeographical distribution in the Australian, Oriental and Palearctic regions. The species Satsumanus satsumae (Matsumura) is recorded for the first time from Zhejiang Province, and a new species Satsumanus discedens sp. nov. is described and illustrated from Guizhou Province, China. The digital photographs of adult male habitus and male genitalia are provided. An updated checklist, global distribution map and taxonomic identification key to known species are provided. The type specimens of the new species are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC).

The soft scale insect genus Marsipococcus Cockerell & Bueker, 1930 (Hemiptera: Coccomorpha: Coccidae) is reported for the first time from China; a new species, Marsipococcus brideliae sp. n., is described and illustrated from Guizhou Province on Bridelia retusa (Phyllanthaceae). A key is given to distinguish all four species in the genus. Type specimens of the new species are deposited at the Institute of Entomology, Guizhou University, Guiyang, China and the collection at the Department of Forestry Protection, Beijing Forestry University, Beijing.

One new genus and three new species of Empoascini from China are described and illustrated: Ventriappendix Ding, Yu & Yang gen. nov. with a new species V. divaricata Ding, Yu & Yang, sp. nov.; Dayus motuoensis Ding, Yu & Yang sp. nov.; and Alebroides hei Ding, Yu & Yang sp. nov. A revised key to males of Chinese species and a checklist to the genus of Dayus are also provided.

Arbuscular mycorrhizal fungi (AMF) are one of the environment-friendly organisms that enhance plant performance. AMF affect the herbivorous insect community by indirectly modifying host plant nutrient uptake, growth, and defense, also known as priming. In the current study, under greenhouse conditions, the effects of inoculating tomato seedlings with four species of AMF, i.e., Funneliformis mosseae, Rhizophagus intraradices, Rhizophagus irregularis, and Glomus iranicus, were studied in relation to tomato plant growth parameters, plant defense enzymes, and total phenol content, and additionally, the life table of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) feeding on these plants was determined. The results demonstrated that the growth parameters of tomato plants, including plant height, stem diameter, number of leaves, root volume, leaf surface area, weight of the root, and aerial organs (containing the leaves and stem), were greater and larger in the AMF-inoculated plants compared to the non-inoculated plants. Furthermore, there were higher defense enzyme activities, including peroxidase, phenylalanine ammonia lyase and polyphenol oxidase, and also higher total phenol contents in the AMF-inoculated plants. The whitefly life table characteristics were decreased in the group feeding on the AMF-inoculated plants. All together, the AMF colonization made the tomato plants more resistant against B. tabaci by improving plant growth and increasing defense enzymes. The degree of priming observed here suggests the potential of AMF to have expansive applications, including their implementation in sustainable agriculture., (© 2024. Sociedade Entomológica do Brasil.)

Ion transport peptide (ITP), a superfamily of arthropod neuropeptides, serves a crucial role in regulating various physiological processes such as diuresis, ecdysis behavior, and wing expansion. However, the molecular characteristics, expression profile, and role of ITP in Sogatella furcifera are poorly understood. To elucidate the characteristics and biological function of ITP in S. furcifera, we employed reverse transcription-polymerase chain reaction (RT-PCR) and RNA interference (RNAi) methods. The identified SfITP gene encodes 117 amino acids. The expression of SfITP gradually increased followed the formation of 3-day-old of 5th instar nymph, peaking initially at 40 min after eclosion, and reaching another peak 24 h after eclosion, with particularly high expression levels in thorax and wing tissues. Notably, SfITP RNAi in 3rd instar nymphs of S. furcifera significantly inhibited the transcript levels of SfITP, resulting in 55% mortality and 78% wing deformity. These findings suggests that SfITP is involved in the regulation of wing expansion in S. furcifera, providing insights into the regulation of insect wing expansion and contributing to the molecular understanding of this process., Competing Interests: Declaration of competing interest All the authors have no conflict of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Background: The white-backed planthopper (WPH), Sogatella furcifera (Horváth), is a destructive rice pest with strong reproductive capacity. To gain insights into the roles of chitinases in the reproductive process of this insect species, this study represents the first-ever endeavor to conduct an in-depth exploration into the reproductive functions of four chitinase genes., Results: In this study, it was observed that four chitinase genes were expressed in female adults, with a relatively high expression level in the ovaries. SfCht2 and SfIDGF1 were highly expressed during later ovarian development. while SfENGase increased and then decreased with ovarian development. SfCht2, SfCht6-2 and SfENGase were highly expressed in fat body on the first and second days after eclosion, whereas SfIDGF1 highest on day 7. Compared with control group, Silencing four chitinase genes inhibited ovarian development and significantly shortened the oviposition period of S. furcifera, reducing egg-laying capacity but not affecting egg hatching. The detection demonstrated that the expression levels of SfVg, SfVgR and 70-90% juvenile hormone (JH) signaling pathway-related reproductive genes was significantly down-regulated. Moreover, SfCht6-2 and SfENGase significantly affected the expression levels of Target of Rapamycin (TOR) signaling pathway genes. SfENGase had the ability to impact nutrient signaling pathways and fatty acid metabolism, repressing vitellogenin synthesis and ultimately influencing ovarian development of S. furcifera., Conclusions: Overall, this study provides insight into the function of chitinases in insect fecundity and is of great significance for enriching the cognition of insect chitinase function. They will become the suitable target genes for controlling the most destructive rice planthoppers. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

A new leafhopper species Phlogothamnus renhuaiensis sp. nov. is described and illustrated from Guizhou Province, China. An updated identification key for the adult male Phlogothamnus species is provided, and a global distribution map showing the geographic distribution of all species is also provided. A cumulative checklist of 10 Phlogothamnus species including the basionym, localities of type materials, type depositories, and updated distribution data is also presented. The type specimens of the new species are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC).

Two new species of genus Metanigrus Tsaur, Yang & Wilson, 1986 (Fulgoromorpha, Meenoplidae), M. afflatus sp. nov. from Hainan Province and M. angularus sp. nov. from Yunnan Province, are described and illustrated, bringing the total number of species within the genus to 8. An updated checklist and identification key to known species of Metanigrus are provided.

The species of Neogreenia MacGillivray (Hemiptera: Coccomorpha: Qinococcidae) are reviewed. The genus is distributed in the Oriental and Palaearctic Regions and now contains seven species. The present study provides updated generic descriptions of all the developmental stages and a brief account of the biology and life cycle of Neogreenia. The genotype, Neogreenia zeylanica (Green, 1896), is redescribed. The following are described and illustrated for the first time: the second-instar nymph, third-instar female, and male third-instar nymph and pupa of N. zizyphi Tang; the second-instar nymph of N. lonicera Wu & Nan; and the second-instar nymph of N. sophorica Wu. Two new species are described and illustrated: Neogreenia ficus Zheng & Wu, sp. n. based on the adult female and Neogreenia tangi Zheng & Wu, sp. n. based on all female instars. These new species bring the total number of described species of Neogreenia to seven. An identification key to all the developmental stages of Neogreenia, and identification keys to species based on adult females and available nymphal instars are provided.

A new species of soft scale insect (Hemiptera: Coccomorpha: Coccidae) belonging to the genus Paralecanium Cockerell & Bueker, P. sabia Tan, Meng & Xing sp. n., is described and illustrated. It was found on the leaves of Sabia swinhoei Hemsl (Sabiaceae) in Guizhou Maolan National Nature Reserve, Guizhou Province, China. Habitat photographs and illustrations are provided. The type material of P. sabia sp. n. is deposited at the Institute of Entomology, Guizhou University, Guiyang, China (GUGC) and in the insect collection at the Department of Forestry Protection, Beijing Forestry University, Beijing, China (NFUC). An identification key to separate the 28 species in Paralecanium, based on the morphology of adult females, is provided.

Two new armoured scale insect species (Hemiptera: Coccomorpha: Diaspididae) are described and illustrated from Guizhou Province, China. Aulacaspis pericampylus sp. n. was collected from Pericampylus glaucus (Menispermaceae) and Aulacaspis multispinata sp. n. was collected from Cinnamomum camphora (Lauraceae). The type specimens of both new species are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC). A key to the Aulacaspis species known from China, based on the morphology of the adult females, is provided.

Hemiptera insects exhibit a close relationship to plants and demonstrate a diverse range of dietary preferences, encompassing phytophagy as the predominant feeding habit while a minority engages in carnivorous or haematophagous behaviour. To counteract the challenges posed by phytophagous insects, plants have developed an array of toxic compounds, causing significant evolutionary selection pressure on these insects. In this study, we employed a comparative genomics approach to analyse the expansion and contraction of gene families specific to phytophagous insect lineages, along with their adaptive evolutionary traits, utilising representative species from the Hemiptera order. Our investigation revealed substantial expansions of gene families within the phytophagous lineages, especially in the Pentatomomorpha branch represented by Oncopeltus fasciatus and Riptortus pedestris . Notably, these expansions of gene families encoding enzymes are potentially involved in hemipteran-plant interactions. Moreover, the adaptive evolutionary analysis of these lineages revealed a higher prevalence of adaptively evolved genes in the Pentatomomorpha branch. The observed branch-specific gene expansions and adaptive evolution likely contribute significantly to the diversification of species within Hemiptera. These results help enhance our understanding of the genomic characteristics of the evolution of different feeding habits in hemipteran insects.

A new leafhopper species Sophonia furcata sp. nov., is described and illustrated from Sichuan Province, China. A key is given to distinguish all Chinese species of the genus. The type specimens of the new species are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC).

The purpose of this paper is to validate 4 generic names and 34 specific names previously introduced in the Deltocephalinae from China (Hemiptera: Cicadellidae) by Li, Dai & Xing (2011). The names are unavailable in the original publication, because of the missing information on the type specimen repository. The following genera and species are introduced as new in this publication: Bambusananus, Li & Xing; Branchana Li; Cyclevertex Li & Xing; Lineana Li & Xing; Abrus biprocessus Li; Abrus graciaedeagus Li; Bambusana biflaka Li; Bambusana nigrimaculata Li; Bambusananus furcatus Li & Xing; Branchana xanthota Li; Cyclevertex furcatum Li & Xing; Lineana albipunctata Li & Xing; Lineana ductaedeagusa Li & Xing; Protensus nigrifrons Li & Xing; Protensus yanheensis Li & Xing; Paramesodes menghaiensis Xing & Li; Yuanamia producta (Xing & Li, 2011); Hishimonoides brevis Li, 2011; Litura tripunctata Li; Changwhania huajiangensis Xing & Li; Elginus productus Xing & Li; Metalimnus maoershanensis Xing & Li; Nicolaus bihamatus Xing & Li; Paralaevicephalus bisubulatus Xing & Li; Paralaevicephalus brevissimus Xing & Li; Paralaevicephalus spinosus Xing & Li; Scaphoideus annulatus Li; Scaphoideus bannaensis Li; Longicornus longus Xing & Li; Melanetettix mengyangensis Xing & Li; Osbornellus aurantius Xing & Li; Osbornellus suiyangensis Xing & Li; Osbornellus conoideus Xing & Li; Phlogothamnus acutaedeagus Li; Phlogothamnus luteoguttatus Li; Phlogothamnus productus Li & Xing; Phlogothamnus rugosus Li; Phlogotettix fanjingshanensis Li.

RNA interference (RNAi) is a widespread post-transcriptional silencing mechanism that targets homologous mRNA sequences for specific degradation. An RNAi-based pest management strategy is target-specific and considered a sustainable biopesticide. However, the specific genes targeted and the efficiency of the delivery methods can vary widely across species. In this study, a spray-induced and nanocarrier-delivered gene silencing (SI-NDGS) system that incorporated gene-specific dsRNAs targeting conserved genes was used to evaluate phenotypic effects in white-backed planthopper (WBPH). At 2 days postspraying, transcript levels for all target genes were significantly reduced and knockdown of two gene orthologs, hsc70-3 and PP-α, resulted in an elevated mortality (>60%) and impaired ecdysis. These results highlight the utility of the SI-NDGS system for identifying genes involved in WBPH growth and development that could be potentially exploitable as high mortality target genes to develop an alternative method for WBPH control.

A new evacanthine leafhopper species Riseveinus elongatus sp. nov., is described and illustrated from Yunnan Province, China. A key is given to distinguish all species of the genus. The type specimen of the new species is deposited in the Institute of Entomology, Guizhou University, Guiyang, China (GUGC).

The sweet potato whitefly, Bemisia tabaci, is an important insect pest that transmits over 200 different plant viruses and causes serious damage to the production of cotton and Solanaceae vegetables. Cyantraniliprole is the first diamide insecticide, showing toxicity against B. tabaci. However, B. tabaci has developed resistance to this insecticide by upregulating the expressions of cytochrome P450 genes such as CYP6CX3, while there is limited information on the regulatory mechanism mediated by miRNA. In the present study, ten miRNAs were predicted to target CYP6CX3, in which miR-276-3p showed an inverse expression pattern with CYP6CX3 in two cyantraniliprole resistant strains and under cyantraniliprole exposure. A luciferase assay demonstrated that miR-276-3p suppressed CYP6CX3 expression by pairing with residues 1445-1453. Overexpression or knockdown of miR-276-3p directly impacted B. tabaci resistance to cyantraniliprole. In addition, exposure to cyantraniliprole led to a significant reduction in the expressions of five genes (drosha, dicer1, dicer2, Ago1, and Ago2A) associated with miRNA biogenesis. Suppressing genes such as drosha, dicer1, and Ago2A reduced the expression of miR-276-3p, increased CYP6CX3 expression, and decreased B. tabaci resistance to cyantraniliprole. These results improve our understanding of the role of miRNAs in P450 regulation and cyantraniliprole resistance in B. tabaci., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Nuclear receptors play a crucial role in various signaling and metabolic pathways, such as insect molting and development. Buprofezin (2-tert-butylimino-3-isopropyl-5-phenyl-perhydro-1, 3, 5-thiadiazin-4-one), a chitin synthesis inhibitor, causes molting deformities and slow death in insects by inhibiting chitin synthesis and interfering with their metabolism. This study investigated whether buprofezin affects insect ecdysteroid signaling pathway. The treatment of buprofezin significantly suppressed the transcription levels of SfHR3 and SfHR4, two nuclear receptor genes, in third-instar nymphs of Sogatella furcifera. Meanwhile, the transcription levels of SfHR3 and SfHR4 in first-day fifth-instar nymphs were induced at 12 h after 20E treatment. In addition, the silencing of SfHR3 and SfHR4 genes in first-day fifth-instar nymphs caused severe developmental delay and molting failure, resulting in a significant reduction of survival rates at 7.36% and 2.99% on the eighth day, respectively. Further analysis showed that the silencing SfHR3 and SfHR4 significantly inhibited the transcription levels of chitin synthesis and degradation-related genes. These results indicate that buprofezin can inhibits chitin synthesis and degradation by suppressing the signal transduction of 20E through SfHR3 and SfHR4, leading to molting failure and death. This study not only expands our understanding of the molecular mechanism of buprofezin in pest control but also lays a foundation for developing new control strategies of RNAi by targeting SfHR3 and SfHR4., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflicts of interest in regard to the contents of this article., (Copyright © 2023 Elsevier Inc. All rights reserved.)

In this paper, we formulate a population suppression model and a population replacement model with periodic impulsive releases of Nilaparvata   lugens infected with wStri . The conditions for the stability of wild- N . l u g e n s -eradication periodic solution of two systems are obtained by applying the Floquet theorem and comparison theorem. And the sufficient conditions for the persistence in the mean of wild N . l u g e n s are also given. In addition, the sufficient conditions for the extinction and persistence of the wild N . l u g e n s in the subsystem without wLug are also obtained. Finally, we give numerical analysis which shows that increasing the release amount or decreasing the release period are beneficial for controlling the wild N . l u g e n s , and the efficiency of population replacement strategy in controlling wild populations is higher than that of population suppression strategy under the same release conditions.

The discovery of the clustered regularly interspaced short palindromic repeat (CRISPR) system has driven gene manipulation technology to a new era with applications reported in organisms that span the tree of life. The utility of CRISPR-mediated editing was further expanded to mRNA following identification of the RNA-targeting Cas13 family of smaller endonuclease proteins. Application of this family to insect research, however, has been more limited. In this study, the smallest Cas13 family member, Cas13d, and guide RNAs (gRNAs) were complexed with a versatile nanomaterial (star polycation, SPc) to generate a proof-of-concept RNA-editing platform capable of disrupting mRNA expression of the eye pigmentation gene tryptophan 2,3-dioxygenase (SfTO) in white-backed planthoppers (WBPHs). The resulting red-eye phenotype was present in 19.76% (with SPc) and 22.99% (without SPc) of the treatment groups and was comparable to the red-eye phenotype generated following conventional RNA interference knockdown (22.22%). Furthermore, the Cas13/gRNA phenotype manifested more quickly than RNA interference. Consistent with the expected Cas13d mechanism, SfTO transcript levels were significantly reduced. Taken together, the results indicate that the SPc-CRISPR-Cas13d/gRNA complex negatively impacted expression of the target gene. These findings confirm the utility of this novel mRNA disruption system in insects and lay the foundation for further development of these tools in the implementation of green agricultural pest management tactics., (© 2023 Institute of Zoology, Chinese Academy of Sciences.)

Background: The phylogenetic position and classification of Athysanini are poorly defined, as it includes a large group of polyphyletic genera that have historically been assigned to it mainly because they still exhibit the most typical deltocephaline genitalic and external body characters but lack the distinctive characteristics that other tribes possess. The bamboo-feeding leafhopper genus Abrus belong to the tribe Athysanini of subfamily Deltocephalinae, which currently comprises 19 valid described species, and are limited to the Oriental and Palaearctic regions in China. Although the taxonomy of Abrus are well updated, the references on comparative mitogenomic analyses of Abrus species are only known for a single species. In this study, we sequenced and analyzed the complete mitochondrial genomes (mitogenomes) of Abrus daozhenensis Chen, Yang & Li, 2012 (16,391bp) and A. yunshanensis Chen, Yang & Li, 2012 (15,768bp) (Athysanini), and compared with published mitogenome sequence of A. expansivus Xing & Li, 2014 (15,904bp)., Results: These Abrus species shared highly conserved mitogenomes with similar gene order to that of the putative ancestral insect with 37 typical genes and a non-coding A + T-rich region. The nucleotide composition of these genomes is highly biased toward A + T nucleotides (76.2%, 76.3%, and 74.7%), AT-skews (0.091 to 0.095, and 0.095), negative GC-skews (- 0.138, - 0.161, and - 0.138), and codon usage. All 22 tRNA genes had typical cloverleaf secondary structures, except for trnS1 (AGN) which lacks the dihydrouridine arm, and distinctively trnG in the mitogenome of A. expansivus lacks the TψC arm. Phylogenetic analyses based on 13 PCGs, 2 rRNA genes, and 22 tRNA genes consistently recovered the monophyletic Opsiini, Penthimiini, Selenocephalini, Scaphoideini, and Athysanini (except Watanabella graminea, previously sequenced species as Chlorotettix nigromaculatus) based on limited available mitogenome sequence data of 37 species., Conclusion: At present, Abrus belongs to the tribe Athysanini based on both morphological and molecular datasets, which is strongly supported in present phylogenetic analyses in both BI and ML methods using the six concatenated datasets: amino acid sequences and nucleotides from different combinations of protein-coding genes (PCGs), ribosomal RNA (rRNAs), and transfer RNA (tRNAs). Phylogenetic trees reconstructed herein based on the BI and ML analyses consistently recovered monophylitic Athysanini, except Watanabella graminea (Athysanini) in Opsiini with high support values., (© 2023. The Author(s).)

Insects rely on odorant-binding proteins (OBPs) for chemical perception, making OBPs a promising target for studying attractants and repellents of pests, such as Bemisia tabaci . However, no reports have reported using B. tabaci OBPs ( Bt OBPs) as pesticide screening targets. To fill this gap, we obtained Bt OBP8 through prokaryotic expression and purification. Then, we confirmed its identity using western blotting and mass spectrometry. Next, we used the sitting drop and hanging drop methods to screen its crystal conditions. Using microscale thermophoresis and isothermal titration calorimetry, we identified the highest affinity ligand, 3l , from 30 compounds. Furthermore, point mutation techniques identified Val119 as a key amino acid residue in binding 31 to Bt OBP8. Finally, we tested the bioactivity of B. tabaci Mediterranean and found that 3l more effectively inhibits the bioactivity of B. tabaci MED than imidacloprid. This study presents a new approach for developing green insecticides specific to B. tabaci MED by targeting OBPs. Conclusively, identifying and targeting specific OBPs can create more targeted and effective pest control strategies without relying on toxic chemicals.

Southern rice black-streaked dwarf virus (SRBSDV) is one of the most damaging rice viruses. The virus decreases rice quality and yield, and poses a serious threat to food security. From this perspective, this review performed a survey of published studies in recent years to understand the current status of SRBSDV and white-backed planthopper (WBPH, Sogatella furcifera) transmission processes in rice. Recent studies have shown that the interactions between viral virulence proteins and rice susceptibility factors shape the transmission of SRBSDV. Moreover, the transmission of SRBSDV is influenced by the interactions between viral virulence proteins and S. furcifera susceptibility factors. This review focused on the molecular mechanisms of key genes or proteins associated with SRBSDV infection in rice via the S. furcifera vector, and the host defense response mechanisms against viral infection. A sustainable control strategy using RNAi was summarized to address this pest. Finally, we also present a model for screening anti-SRBSDV inhibitors using viral proteins as targets. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

Japanagallia is a genus of Cicadomorpha in the family of leafhoppers that are plant piercing-sucking insects, and it is difficult to distinguish by morphological characteristics. So far, only one complete mitochondrial genome data has been reported for the genus Japanagallia . Therefore, in order to better understand this group, we assembled and annotated the complete mitochondrial genomes of five Japanagallia species, and analyzed their codon usage patterns. Nucleotide composition analysis showed that AT content was higher than GC content, and the protein-coding sequences preferred to end with A/T at the third codon position. Relative synonymous codon usage analysis revealed most over-represented codon ends with A or T. Parity plot analysis revealed the codon usage bias of mitochondrial genes was influenced by both natural selection and mutation pressure. In the neutrality plot, the slopes of regression lines were < 0.5, suggesting that natural selection was playing a major role while mutation pressure was of minor importance. The effective number of codons showed that the codon usage bias between genes and genomes was low. Correspondence analysis revealed that the codon usage pattern differed among 13 protein-coding genes. Phylogenetic analyses based on three datasets using two methods (maximum likelihood and Bayesian inference), restored the Megophthalminae monophyly with high support values (bootstrap support values (BS) = 100, Bayesian posterior probability (PP) = 1). In the obtained topology, the seven Japanagallia species were clustered into a monophyletic group and formed a sister group with Durgade . In conclusion, our study can provide a reference for the future research on organism evolution, identification and phylogeny relationships of Japanagallia species ., Competing Interests: The authors declare there are no competing interests., (©2023 Li et al.)

Glutamine: fructose-6-phosphate aminotransferase (GFAT), the fourth enzyme in the chitin synthesis pathway, exerts wide-ranging effects on the growth and development of organisms. However, the role of GFAT in Sogatella furcifera remains unknown. In this study, the functional significance of the GFAT gene of S. furcifera was analyzed using a reverse transcription-polymerase chain reaction and RNA interference (RNAi) analyses. The complementary DNA sequence of SfGFAT was 3162 bp in length and contained a 2067 bp open reading frame encoding 688 amino acid residues. Structural domain analysis indicated that the Sf GFAT protein consisted of one glutamine aminotransferase class 2 domain and two sugar isomerase domains. Expression profile analysis revealed that SfGFAT was expressed throughout the egg, nymph, and adult phases and was strongly expressed on the first day of each nymph stage and in the integuments of five tissues. RNAi results revealed that SfGFAT gene silencing significantly inhibited the mRNA expression of the target gene and resulted in severe mortality among S. furcifera . In summary, these findings demonstrate that SfGFAT plays a critical role in the development of S. furcifera . Moreover, these results may aid in the development of methods to control the spread of S. furcifera .

The Chinese cixiid planthopper tribe Eucarpiini is studied taxonomically. Four genera and 29 species belonging to Eucarpiini are reported from China, including 15 new species of three genera: Dilacreon (Dilacreon) deltodontus sp. nov., Dilacreon (Eluzalmon) apiculatus sp. nov., D. (E.) arcuatus sp. nov., D. (E.) biprocessus sp. nov., D. (E.) congjiangensis sp. nov., D. (E.) distentus sp. nov., D. (E.) erectus sp. nov., D. (E.) falcatus sp. nov., D. (E.) parapentagonus sp. nov., D. (E.) transversus sp. nov., Kirbyana projecta sp. nov., K. spinata sp. nov., Neocarpia brevispina sp. nov., N. longispina sp. nov. and N. trispina sp. nov.. All species dealt with are described and illustrated and keys for genera and their species are also given.

Background: The white-backed planthopper (WBPH, Sogatella furcifera) is a major rice pest that exhibits condition dependent wing dimorphisms - a macropterous (long wing) form and a brachypterous (short wing) form. Although, the gene cascade that regulates wing development and dimorphic differentiation has been largely defined, the utility of these genes as targets for pest control has yet to be fully explored., Results: Five genes typically associated with the developmental signaling network, armadillo (arm), apterous A (apA), scalloped (sd), dachs (d), and yorkie (yki) were identified from the WBPH genome and their roles in wing development assessed following RNA interference (RNAi)-mediated knockdown. At 5 days-post injection, transcript levels for all five targets were substantially decreased compared with the dsGFP control group. Among the treatment groups, those injected with dsSfarm had the most pronounced effects on transcript reduction, mortality (95 ± 3%), and incidence (45 ± 3%) of wing deformities, whereas those injected with dsSfyki had the lowest incidence (6.7 ± 4%). To assess the utility of topical RNAi for Sfarm, we used a spray-based approach that complexed a large-scale, bacteria-based double-stranded RNA (dsRNA) expression pipeline with star polycation (SPc) nanoparticles. Rice seedlings infested with third and fourth instar nymphs were sprayed with SPc-dsRNA formulations and RNAi phenotypic effects were assessed over time. At 2 days post-spray, Sfarm transcript levels decreased by 86 ± 9.5% compared with dsGFP groups, and the subsequent incidences of mortality and wing defects were elevated in the treatment group., Conclusions: This study characterized five genes in the WBPH developmental signaling cascade, assessed their impact on survival and wing development via RNAi, and developed a nanoparticle-dsRNA spray approach for potential field control of WBPH. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

Nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P450 reductase (CPR), a crucial electron-transfer partner of P450 systems, is required for various biological reactions catalyzed by P450 monooxygenase. Our previous study indicated that enhanced P450 enzyme detoxification and CYP6ER1 overexpression contributed to sulfoxaflor resistance in Nilaparvata lugens. However, the association between CPR, sulfoxaflor resistance, and neonicotinoid cross-resistance in N. lugens remains unclear. In this study, the sulfoxaflor-resistant (SFX-SEL) (RR = 254.04-fold), resistance-decline (DESEL) (RR = 18.99-fold), and susceptible unselected (UNSEL) strains of N. lugens with the same genetic background were established. Real-time quantitative polymerase chain reaction (RT-qPCR) revealed that the N. lugens CPR (NlCPR) expression level in the SFX-SEL strain was 6.85-fold and 6.07-fold higher than in UNSEL and DESEL strains, respectively. NlCPR expression was significantly higher in the abdomens of UNSEL, DESEL, and SFX-SEL fourth-instar nymphs than in other tissues (thoraxes, heads, and legs). Additionally, sulfoxaflor stress significantly increased NlCPR mRNA levels in the UNSEL, SFX-SEL and DESEL strains. NlCPR silencing by RNA interference (RNAi) dramatically increased the susceptibility of the UNSEL, DESEL, and SFX-SEL strains to sulfoxaflor, but the recovery of SFX-SEL was more obvious. Furthermore, NlCPR silencing led to a significant recovery in susceptibility to nitenpyram, dinotefuran, clothianidin, and thiamethoxam across all strains (UNSEL, DESEL, and SFX-SEL), with the greatest degree of recovery in the sulfoxaflor-resistant strain (SFX-SEL). Our findings suggest that NlCPR overexpression contributes to sulfoxaflor resistance and neonicotinoid cross-resistance in N. lugens. This will aid in elucidating the significance of CPR in the evolution of P450-mediated metabolic resistance in N. lugens., Competing Interests: Declaration of Competing Interest The authors declare that no competing interests exist., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Krisna species are insects that have piercing-sucking mouthparts and belong to the Krisnini tribe in the Iassinae subfamily of leafhoppers in the Cicadellidae family. In this study, we sequenced and compared the mitochondrial genomes (mitogenomes) of four Krisna species. The results showed that all four mitogenomes were composed of cyclic double-stranded molecules and contained 13 protein-coding genes (PCGs) and 22 and 2 genes coding for tRNAs and rRNAs, respectively. Those mitogenomes exhibited similar base composition, gene size, and codon usage patterns for the protein-coding genes. The analysis of the nonsynonymous substitution rate (Ka)/synonymous substitution rate (Ks) showed that evolution occurred the fastest in ND4 and the slowest in COI . 13 PCGs that underwent purification selection were suitable for studying phylogenetic relationships within Krisna . ND2 , ND6 , and ATP6 had highly variable nucleotide diversity, whereas COI and ND1 exhibited the lowest diversity. Genes or gene regions with high nucleotide diversity can provide potential marker candidates for population genetics and species delimitation in Krisna . Analyses of parity and neutral plots showed that both natural selection and mutation pressure affected the codon usage bias. In the phylogenetic analysis, all subfamilies were restored to a monophyletic group; the Krisnini tribe is monophyletic, and the Krisna genus is paraphyletic. Our study provides novel insights into the significance of the background nucleotide composition and codon usage patterns in the CDSs of the 13 mitochondrial PCGs of the Krisna genome, which could enable the identification of a different gene organization and may be used for accurate phylogenetic analysis of Krisna species.

A new species of armoured scale insect, Formosaspis fanjingensis sp. n. (Hemiptera: Coccomorpha: Diaspididae), is described; it was found on Chimonobambusa spp. (Poaceae; Bambusoideae) in Guizhou Province, China. Habitat photographs and taxonomic illustrations are provided. The type specimens are deposited at the Institute of Entomology, Guizhou University, Guiyang, China (GUGC). An identification key based on the morphology of adult females is provided to separate all the species in the genus.

Dicer1 plays a vital role in the formation of mature miRNA and regulates the growth, development, and reproduction of insects. However, it remains to be clarified whether Dicer1 is involved in regulating the biological processes underlying molting and reproduction of Sogatella furcifera (Horváth). Herein, SfDicer1 expression fluctuated in all the developmental stages of S. furcifera and increased as molting progressed. SfDicer1 exhibited high expression in the integument, head, fat body, and ovary of the insects. SfDicer1 dsRNA injection into 1-day-old fourth instar nymphs of S. furcifera substantially decreased the survival rate and expression of the lethal phenotypes of wing malformation and molting defects and significantly inhibited the expression of four conserved miRNAs associated with molting development. Subsequently, following the knockdown of SfDicer1 in the newly emerged (1-12 h) females of S. furcifera, SfVg and SfVgR expression levels were decreased, thereby delaying ovarian development, decreasing the number of eggs, and considerably reducing the hatching rate compared with those of the control. Finally, after silencing SfDicer1 for 48 h, the comparative transcriptome analysis of differentially expressed genes revealed considerable enrichment of the Gene Ontology terms structural constituent of cuticle, structural molecule activity, chitin metabolic process, amino sugar metabolic process, and intracellular anatomical structure, indicating that SfDicer1 inhibition affects the transcription of genes associated with growth and development. Thus, our results suggest that SfDicer1 is essential in the molting, survival, ovarian development, and fecundity of S. furcifera and is a suitable target gene for developing an RNAi-based strategy targeting the most destructive rice insect pest., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest. The authors alone are responsible for the content and writing of the paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Two new species of the genus Deferunda Distant, 1912, D. dentata sp. nov. and D. interanea sp. nov. from China (Shandong and Hainan provinces, respectively), are described and illustrated, bringing the total number of species within the genus to 17. The male genitalia of D. acuminata Chou & Wang, 1985 is described and illustrated for the first time. Geographical information, a checklist and key to all known species of Deferunda are provided.

Background: Epidermal growth factor receptor (EGFR), zinc finger homeodomain-2 (zfh-2), Abdominal-A (Abd-A), and Abdominal-B (Abd-B) regulate the growth and development of the insect abdomen. However, their potential roles in pest control have not been fully assessed. The development of insecticide resistance to multiple chemistries in the white-backed planthopper (WBPH), a major pest of rice, has prompted interest in novel pest control approaches that are ecologically friendly. Although pest management approaches based on double-stranded RNA (dsRNA)-mediated RNA interference (RNAi) have potential, their susceptibility to degradation limits large-scale field applications. These limitations, however, can be overcome with nanoparticle-dsRNA complexes that have greater environmental stability and improved cellular uptake., Results: In this study, at 5 days post-injection, transcripts for the four gene targets were reduced relative to controls and all of the experimental groups exhibited significant phenotypic defects and increased mortality. To evaluate the potential of these gene targets for field applications, a nanocarrier-dsRNA spray delivery system was assessed for RNAi efficacy. At 11 days post-spray, significant phenotypic defects and increased mortality were observed in all experimental groups., Conclusion: Taken together, the results confirm the suitability of the target genes (SfEGFR, Sfzfh-2, SfAbd-A, and SfAbd-B) for pest management and demonstrate the efficacy of the nanocarrier spray system for inducing RNAi-mediated knockdown. As such, the study lays the foundation for the further development and optimization of this technology for large-scale field applications. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)

As a significant pest of rice the white-backed planthopper (WBPH) Sogatella furcifera is a focus of pest management. However, traditional chemical-based control methods risk the development of pesticide resistance as well as severe ecological repercussions. Although nanoparticle-encapsulated dsRNAs provide a promising alternative method for sustainable pest management, gene targets specific to WBPH have yet to be optimized. Genes in the tyrosine-melanin pathway impact epidermal melanization and sclerotization, two processes essential for insect development and metabolism, have been proposed as good candidate targets for pest management. Seven genes (aaNAT, black, DDC, ebony, tan, TH, and yellow-y) in this group were identified from WBPH genome and functionally characterized by using RNAi for their impact on WBPH body color, development, and mortality. Knockdown of SfDDC, Sfblack, SfaaNAT, and Sftan caused cuticles to turn black, whereas Sfyellow-y and Sfebony knockdown resulted in yellow coloration. SfTH knockdown resulted in pale-colored bodies and high mortality. Additionally, an Escherichia coli expression system for large-scale dsRNA production was coupled with star polycation nanoparticles to develop a sprayable RNAi method targeting SfTH that induced high WBPH mortality rates on rice seedlings. These findings lay the groundwork for the development of large-scale dsRNA nanoparticle sprays as a WBPH control method., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Peng He reports financial support was provided by Guizhou University. Peng He reports a relationship with Guizhou University that includes: employment., (Copyright © 2023 Elsevier B.V. All rights reserved.)