Effect of iron-based nanomaterials on organic carbon dynamics and greenhouse gas emissions during composting process.

Iron-based nanomaterials as effective additives can enhance the quality and safety of compost. However, their influence on organic carbon fractions changes and greenhouse gas emissions during composting remains unclear. This study demonstrated that iron-based nanomaterials facilitate the conversion of light organic carbon fraction into heavy organic carbon fraction, with the iron-based nanomaterials group showing a significantly higher heavy organic carbon fraction content (41.88%) compared to the control group (35.71%). This shift led to an increase in humic substance content (77.5 g/kg) and a reduction in greenhouse gas emissions, with CO2, CH4, and N2O emissions decreasing by 20.5%, 39.7%, and 55.4%, respectively. Additionally, CO2-equivalent emissions were reduced by 42.9%. Microbial analysis revealed that iron-based nanomaterials increased the abundance of Bacillus and reduced the abundance of methane-producing archaea such as Methanothermobacter and Methanomassiliicoccus. These results indicated that the role of iron-based nanomaterials in regulating reactive oxygen species production and specific microbial communities involved in humification process. This study provides a practical strategy for improving waste utilization efficiency and mitigating climate change.

Integrated transcriptome and 1H NMR-based metabolome to explore the potential mechanism of Spodoptera litura in response to flupyrimin.

Flupyrimin (FLP) is a novel class of insecticide acting on insect nicotinic acetylcholine receptor (nAChR) and shows robust insecticidal activity. However, the toxicological effects of FLP on Spodoptera litura have not been revealed. In this study, the results showed that the larval survival rate decreased significantly with increasing concentration of FLP. The hematoxylin-eosin (HE) staining showed that FLP exposure damages the structure of the larval midgut. Additionally, FLP treatments significantly increased the activities of detoxification (GST and CarE) and digestive (α-Amylase and Trypsin) enzymes and reduced lipase activity. Transcriptome sequencing identified 855, 1493 and 735 differentially expressed genes (DEGs) at 12 h, 24 h and 48 h after exposure to 3 mM FLP, respectively. Gene function enrichment analysis revealed that DEGs were mainly related to fatty acid metabolic, protein processing in the endoplasmic reticulum and drug metabolism-cytochrome P450. The DEGs associated with food digestion and detoxification was validated by reverse-transcription quantitative PCR (RT-qPCR). Furthermore, a total of fifteen energy-related metabolites were identified, among which thirteen metabolisms were significantly influenced after FLP treatment based on 1H NMR-based metabolome analysis, including tyrosine, glucose, trehalose, malate, threonine, proline, glycine, lysine, citrate, alanine, lactate, valine, and leucine. Taken together, these results provide useful information for revealing the toxicological effect of FLP against S. litura.

Characterization of an RR-2 cuticle protein DcCP8 and its potential application based on SPc nanoparticle-wrapped dsRNA in Diaphorina citri.

BACKGROUND: The insect cuticle consists of chitin fibers and a protein matrix, which plays an important role in protecting the body from invasion of various pathogens and prevents water loss. Periodic synthesis and degradation of the cuticle is required for the growth and development of insects. Key genes involved in cuticle formation have long been considered a potential target for pest control. RESULTS: In this study, a member of the RR-2 subfamily of cuticular protein 8 (DcCP8) was identified from the Diaphorina citri genome database. Immunofluorescence analysis suggested that DcCP8 was mainly located in the Diaphorina citri exocuticle and can be induced to up-regulate 12 h following 20-hydroxyecdysone (20E) treatment. Silencing of DcCP8 by RNA interference (RNAi) significantly disrupted the metamorphosis to the adult stage, and improved the permeability of the cuticle. Transmission electron microscopy (TEM) analysis revealed that the synthesis of the exocuticle was impressed after silencing of DcCP8. Furthermore, the recombinant DcCP8 protein exhibited chitin-binding properties in vitro, down-regulation of DcCP8 significantly inhibited expression levels of chitin metabolism-related genes. Additionally, a sprayable RNAi method targeting DcCP8 based on star polycation (SPc) nanoparticles-wrapped double-stranded RNA (dsRNA) significantly increased Diaphorina citri mortality. Transcriptome sequencing further confirmed that genes associated with the endocytic pathway and immune response were up-regulated in Diaphorina citri after SPc treatment. CONCLUSIONS: The current study indicated that DcCP8 is critical for the formation of Diaphorina citri exocuticles, and lays a foundation for Diaphorina citri control based on large-scale dsRNA nanoparticles. © 2024 Society of Chemical Industry.

A Combinatorial Single-Molecule Real-Time and Illumina Sequencing Analysis of Postembryonic Gene Expression in the Asian Citrus Psyllid Diaphorina citri.

Huanglongbing (HLB) is a systemic plant disease caused by 'Candidatus Liberibacter asiaticus (CLas)' and transmitted by Diaphorina citri. D. citri acquires the CLas bacteria in the nymph stage and transmits it in the adult stage, indicating that molting from the nymph to adult stages is crucial for HLB transmission. However, the available D. citri reference genomes are incomplete, and gene function studies have been limited to date. In the current research, PacBio single-molecule real-time (SMRT) and Illumina sequencing were performed to investigate the transcriptome of D. citri nymphs and adults. In total, 10,641 full-length, non-redundant transcripts (FLNRTs), 594 alternative splicing (AS) events, 4522 simple sequence repeats (SSRs), 1086 long-coding RNAs (lncRNAs), 281 transcription factors (TFs), and 4459 APA sites were identified. Furthermore, 3746 differentially expressed genes (DEGs) between nymphs and adults were identified, among which 30 DEGs involved in the Hippo signaling pathway were found. Reverse transcription-quantitative PCR (RT-qPCR) further validated the expression levels of 12 DEGs and showed a positive correlation with transcriptome data. Finally, the spatiotemporal expression pattern of genes involved in the Hippo signaling pathway exhibited high expression in the D. citri testis, ovary, and egg. Silencing of the D. citri transcriptional co-activator (DcYki) gene significantly increased D. citri mortality and decreased the cumulative molting. Our results provide useful information and a reliable data resource for gene function research of D. citri.

Synergistic effects of Fe-based nanomaterial catalyst on humic substances formation and microplastics mitigation during sewage sludge composting.

In this study, a novel Fe-based nanomaterial catalyst (Fe0/FeS) was synthesized via a self-heating process and employed to explore its impact on the formation of humic substances and the mitigation of microplastics. The results reveal that Fe0/FeS exhibited a significant increase in humic acid content (71.01 mg kg-1). Similarly, the formation of humic substances resulted in a higher humification index (4.91). Moreover, the addition of Fe0/FeS accelerated the degradation of microplastics (MPs), resulting in a lower concentration of MPs (9487 particles/kg) compared to the control experiments (22792 particles/kg). Fe0/FeS significantly increased the abundance of medium-sized MPs (50-200 µm) and reduced the abundance of small-sized (10-50 µm) and large-sized MPs (>1000 µm). These results can be attributed to the Fe0/FeS regulating the ▪OH production and specific microorganisms to promote humic substance formation and the degradation of MPs. This study proposes a feasible strategy to improve composting characteristics and reduce contaminants.

Natural Coumarin Shows Toxicity to Spodoptera litura by Inhibiting Detoxification Enzymes and Glycometabolism.

Coumarin and its derivatives are plant-derived compounds that exhibit potent insecticidal properties. In this study, we found that natural coumarin significantly inhibited the growth and development of Spodoptera litura larvae through toxicological assay. By transcriptomic sequencing, 80 and 45 differentially expressed genes (DEGs) related to detoxification were identified from 0 to 24 h and 24 to 48 h in S. litura after coumarin treatment, respectively. Enzyme activity analysis showed that CYP450 and acetylcholinesterase (AChE) activities significantly decreased at 48 h after coumarin treatment, while glutathione S-transferases (GST) activity increased at 24 h. Silencing of SlCYP324A16 gene by RNA interference significantly increased S. litura larval mortality and decreased individual weight after treatment with coumarin. Additionally, the expression levels of DEGs involved in glycolysis and tricarboxylic acid (TCA) cycle were inhibited at 24 h after coumarin treatment, while their expression levels were upregulated at 48 h. Furthermore, metabonomics analysis identified 391 differential metabolites involved in purine metabolism, amino acid metabolism, and TCA cycle from 0 to 24 h after treated with coumarin and 352 differential metabolites associated with ATP-binding cassette (ABC) transporters and amino acid metabolism. These results provide an in-depth understanding of the toxicological mechanism of coumarin on S. litura.

Alternative splicing of chitin deacetylase 2 regulates chitin and fatty acid metabolism in Asian citrus psyllid, Diaphorina citri.

Chitin plays an important role in the development and molting of insects. The key genes involved in chitin metabolism were considered promising targets for pest control. In this study, two splice variants of chitin deacetylase 2 (CDA2) from Diaphorina citri were identified, including DcCDA2a and DcCDA2b. Bioinformatics analysis revealed that DcCDA2a and DcCDA2b encoded 550 and 544 amino acid residues with a signal peptide, respectively. Spatio-temporal expression patterns analysis showed that DcCDA2a and DcCDA2b were highly expressed in D. citri wing and nymph stages. Moreover, DcCDA2a and DcCDA2b expression levels were induced by 20-hydroxyecdysone (20E). Silencing DcCDA2a by RNA interference (RNAi) significantly disrupted the D. citri molting and increased D. citri mortality and malformation rate, whereas inhibition of DcCDA2b resulted in a semimolting phenotype. Furthermore, silencing DcCDA2a and DcCDA2b significantly suppressed D. citri chitin and fatty acid metabolism. Our results indicated that DcCDA2 might play crucial roles in regulating D. citri chitin and fatty acid metabolism, and it could be used as a potential target for controlling D. citri.

New Insights into the Plutella xylostella Detoxifying Enzymes: Sequence Evolution, Structural Similarity, Functional Diversity, and Application Prospects of Glucosinolate Sulfatases.

Brassica plants have glucosinolate (GLs)-myrosinase defense mechanisms to deter herbivores. However, Plutella xylostella specifically feeds on Brassica vegetables. The larvae possess three glucosinolate sulfatases (PxGSS1-3) that compete with plant myrosinase for shared GLs substrates and produce nontoxic desulfo-GLs (deGLs). Although PxGSSs are considered potential targets for pest control, the lack of a comprehensive review has hindered the development of PxGSSs-targeted pest control methods. Recent advances in integrative multi-omics analysis, substrate-enzyme kinetics, and molecular biological techniques have elucidated the evolutionary origin and functional diversity of these three PxGSSs. This review summarizes research progress on PxGSSs over the past 20 years, covering sequence properties, evolution, protein modification, enzyme activity, structural variation, substrate specificity, and interaction scenarios based on functional diversity. Finally, we discussed the potential applications of PxGSSs-targeted pest control technologies driven by artificial intelligence, including CRISPR/Cas9-mediated gene drive, transgenic plant-mediated RNAi, small-molecule inhibitors, and peptide inhibitors. These technologies have the potential to overcome current management challenges and promote the development and field application of PxGSSs-targeted pest control.

Exploring the mechanisms of humic acid mediated degradation of polystyrene microplastics under ultraviolet light conditions.

Microplastics (MPs) are emerging pollutants that interact extensively with dissolved organic matter (DOM) and this influences the environmental behavior of MPs in aqueous ecosystems. However, the effect of DOM on the photodegradation of MPs in aqueous systems is still unclear. The photodegradation characteristics of polystyrene microplastics (PS-MPs) in an aqueous system in the presence of humic acid (HA, a signature compound of DOM) under ultraviolet light conditions were investigated in this study through Fourier transform infrared spectroscopy coupled with two-dimensional correlation analysis, electron paramagnetic resonance, and gas chromatography-mass spectrometry (GC/MS). HA was found to promote higher levels of reactive oxygen species (0.631 mM of ▪OH), which accelerated the photodegradation of PS-MPs, with a higher degree of weight loss (4.3%), higher level of oxygen-containing functional groups, and lower average particle size (89.5 µm). Likewise, GC/MS analysis showed that HA contributed to a higher content of oxygen-containing compounds (42.62%) in the photodegradation of PS-MPs. Moreover, the intermediates and final degradation products of PS-MPs with HA were significantly different in the absence of HA during 40 days of irradiation. These results provide an insight into the co-existing compounds on the degradation and migration processes of MP and also support further research toward the remediation of MPs pollution in aqueous ecosystems.

Sex-specific transcription and DNA methylation landscapes of the Asian citrus psyllid, a vector of huanglongbing pathogens.

The relationship of DNA methylation and sex-biased gene expression is of high interest, it allows research into mechanisms of sexual dimorphism and the development of potential novel strategies for insect pest control. The Asian citrus psyllid, Diaphorina citri Kuwayama, is a major vector for the causative agents of Huanglongbing (HLB), which presents an unparalleled challenge to citrus production worldwide. Here, we identify the X chromosome of D. citri and investigate differences in the transcription and DNA methylation landscapes between adult virgin males and females. We find a large number of male-biased genes on the autosomes and a depletion of such on the X chromosome. We have also characterized the methylome of D. citri, finding low genome-wide levels, which is unusual for an hemipteran species, as well as evidence for both promoter and TE methylation. Overall, DNA methylation profiles are similar between the sexes but with a small number of differentially methylated genes found to be involved in sex differentiation. There also appears to be no direct relationship between differential DNA methylation and differential gene expression. Our findings lay the groundwork for the development of novel epigenetic-based pest control methods, and given the similarity of the D. citri methylome to some other insect species, these methods could be applicable across agricultural insect pests.

Single-molecular insights into the breakpoint of cellulose nanofibers assembly during saccharification.

Plant cellulose microfibrils are increasingly employed to produce functional nanofibers and nanocrystals for biomaterials, but their catalytic formation and conversion mechanisms remain elusive. Here, we characterize length-reduced cellulose nanofibers assembly in situ accounting for the high density of amorphous cellulose regions in the natural rice fragile culm 16 (Osfc16) mutant defective in cellulose biosynthesis using both classic and advanced atomic force microscopy (AFM) techniques equipped with a single-molecular recognition system. By employing individual types of cellulases, we observe efficient enzymatic catalysis modes in the mutant, due to amorphous and inner-broken cellulose chains elevated as breakpoints for initiating and completing cellulose hydrolyses into higher-yield fermentable sugars. Furthermore, effective chemical catalysis mode is examined in vitro for cellulose nanofibers conversion into nanocrystals with reduced dimensions. Our study addresses how plant cellulose substrates are digestible and convertible, revealing a strategy for precise engineering of cellulose substrates toward cost-effective biofuels and high-quality bioproducts.

Quantitative ubiquitylome crosstalk with proteome analysis revealed cytoskeleton proteins influence CLas pathogen infection in Diaphorina citri.

Huanglongbing (HLB), also known as citrus greening disease, is caused by Candidatus Liberbacter asiaticus (CLas) and transmitted by Diaphorina citri. Previous studies reported that CLas infection significantly influences the structure of the D. citri cytoskeleton. However, the mechanisms through which CLas manipulates cytoskeleton-related proteins remain unclear. In this study, we performed quantitative ubiquitylome crosstalk with the proteome to reveal the roles of cytoskeleton-related proteins during the infection of D. citri by CLas. Western blotting revealed a significant difference in ubiquitination levels between the CLas-free and CLas-infected groups. According to ubiquitylome and 4D label-free proteome analysis, 343 quantified lysine ubiquitination (Kub) sites and 666 differentially expressed proteins (DEPs) were identified in CLas-infected groups compared with CLas-free groups. A total of 53 sites in 51 DEPs were upregulated, while 290 sites in 192 DEPs were downregulated. Furthermore, functional enrichment analysis indicated that 18 DEPs and 21 lysine ubiquitinated proteins were associated with the cytoskeleton, showing an obvious interaction. Ubiquitination of D. citri tropomyosin was confirmed by immunoprecipitation, Western blotting, and LC-MS/MS. RNAi-mediated knockdown of tropomyosin significantly increased CLas bacterial content in D. citri. In summary, we provided the most comprehensive lysine ubiquitinome analysis of the D. citri response to CLas infection, thus furthering our understanding of the role of the ubiquitination of cytoskeleton proteins in CLas infection.

Silencing of Glycogen Synthase Kinase 3 Significantly Inhibits Chitin and Fatty Acid Metabolism in Asian Citrus Psyllid, Diaphorina citri.

Glycogen is a predominant carbohydrate reserve in various organisms, which provides energy for different life activities. Glycogen synthase kinase 3 (GSK3) is a central player that catalyzes glucose and converts it into glycogen. In this study, a GSK3 gene was identified from the D. citri genome database and named DcGSK3. A reverse transcription quantitative PCR (RT-qPCR) analysis showed that DcGSK3 was expressed at a high level in the head and egg. The silencing of DcGSK3 by RNA interference (RNAi) led to a loss-of-function phenotype. In addition, DcGSK3 knockdown decreased trehalase activity, glycogen, trehalose, glucose and free fatty acid content. Moreover, the expression levels of the genes associated with chitin and fatty acid synthesis were significantly downregulated after the silencing of DcGSK3. According to a comparative transcriptomics analysis, 991 differentially expressed genes (DEGs) were identified in dsDcGSK3 groups compared with dsGFP groups. A KEGG enrichment analysis suggested that these DEGs were primarily involved in carbon and fatty acid metabolism. The clustering analysis of DEGs further confirmed that chitin and fatty acid metabolism-related DEGs were upregulated at 24 h and were downregulated at 48 h. Our results suggest that DcGSK3 plays an important role in regulating the chitin and fatty acid metabolism of D. citri.

New insights into the distribution and interaction mechanism of microplastics with humic acid in river sediments.

Information on the distribution and interaction of microplastics (MPs) and humic acids (HAs) in river sediment has not been fully explored. This study assessed the distribution and interaction of MPs with HAs at different depths in river sediments. The results delineated that the average abundance of MPs in the 0-10 cm layer (190 ± 20 items/kg) was significantly lower than that in the 11-20 cm and 21-30 cm layers (211 ± 10 items/kg and 238 ± 18 items/kg, respectively). Likewise, the large MP particles mainly existed in the 0-10 cm layer (31.53%-37.87%), while small MP particles were found in the 21-30 cm layers (73.23%-100%). Moreover, HAs in MPs showed a transformation from low molecular weight to high molecular weight with an increase in depth from 0-10 cm to 21-30 cm, which may contribute to the distribution of MPs in the river sediments. These results provide new insight into the migration of MP pollution in river sediments, but further research needs to assess the interaction of MP with HA for mitigating MP pollution in river sediment.

Bombyx mori ferritin heavy-chain homolog facilitates BmNPV proliferation by inhibiting reactive oxygen species-mediated apoptosis.

Ferritin heavy-chain homolog (FerHCH), an iron-binding protein, plays an important role in the host defense against oxidative stress and pathogen infections. In our previous research, Bombyx mori native ferritin had an interaction with B. mori nucleopolyhedrovirus (BmNPV). However, the underlying molecular mechanism of single ferritin homolog responses to BmNPV infection remains unclear. In this study, we found that BmNPV titer and B. mori FerHCH (BmFerHCH) expression were positively correlated with the ferric iron concentration. We performed RNA interference (RNAi) and overexpression experiments to investigate the effects of BmFerHCH on BmNPV proliferation. BmFerHCH knockdown suppressed BmNPV proliferation in vivo and in vitro, whereas BmFerHCH overexpression facilitated BmNPV proliferation. In addition, the oxidative stress level was increased significantly in BmN cells after budded virus infection, while BmFerHCH could neutralize the increased ROS production induced by BmNPV. Of note, we found that ROS was involved in BmNPV-induced apoptosis. Through inhibiting ROS, apoptosis was suppressed by BmFerHCH, whereas BmFerHCH knockdown facilitated apoptosis. Therefore, we hypothesize that BmFerHCH-mediated inhibition of virus-induced apoptosis depends on suppressing ROS accumulation and, thereby, facilitates virus replication. These results suggest that BmFerHCH plays an important role in facilitating BmNPV proliferation and modulating BmFerHCH is potential strategy for studying host-pathogen interactions.

Silencing of Chitin-Binding Protein with PYPV-Rich Domain Impairs Cuticle and Wing Development in the Asian Citrus Psyllid, Diaphorina citri.

Chitin is a major component of the arthropod exoskeleton, always working together with chitin-binding proteins to maintain the functions of extracellular structures. In the present study, we identified a cuticle protein 64 from Diaphorina citri using a chitin-binding assay. Bioinformatics analysis revealed that DcCP64 contained eight conserved PYPV motifs but lacked a Rebers-Riddiford (R-R) consensus and other chitin-binding domains. RT-qPCR analysis suggested that DcCP64 had the highest expression level in the wing and fifth-instar nymph stage. Knockdown of DcCP64 by RNA interference (RNAi) resulted in a malformed-wing phenotype, higher mortality and decreased molting rate. Furthermore, transcriptomics analysis revealed that 1244 differentially expressed genes (DEGs) were up-regulated and 580 DEGs were down-regulated, compared with dsDcCP64 groups and dsGFP groups. KEGG enrichment analysis revealed that up-regulated DEGs were mainly related to oxidative phosphorylation, whereas down-regulated DEGs were mainly involved in the MAPK and FoxO signaling pathways. Moreover, inhibition of DcCP64 significantly affected the cuticle surface, and increased the permeability of the abdomen and wings. Further chitin- and cellulose-binding assay confirmed the chitin-binding properties of recombinant DcCP64 in vitro. These results indicate that DcCP64 might play an important role in the cuticle and wing development of D. citri.

Insights into pectin dominated enhancements for elimination of toxic Cd and dye coupled with ethanol production in desirable lignocelluloses.

Pectin is a minor wall polysaccharide with potential applications for bioproducts. Despite the application of specific plants and biomass-based sorbents for environmental remediation, little has been reported about characteristic roles of pectin. Using the natural rice mutant (Osfc16) treated with Cd, this study explored that pectin could predominately enhance Cd accumulation with lignocellulose, mainly due to remarkably raised uronic acids deposition. The Cd-treatment further reduced lignocellulose recalcitrance for significantly enhanced biomass saccharification and bioethanol production along with almost complete Cd release. Using all remaining fermentation rice residues that are of typical ribbon-structure and large surface, this study generated novel biosorbents by optimal chemical oxidation with the pectin extraction from citrus peels, and examined consistently raised Cd and methylene blue (MB) adsorption capacities. Therefore, this work has proposed a mechanism model about multiple pectin enrichment roles for Cd and MB removals in agricultural and industry locations with full lignocellulose utilization towards bioethanol production.

Functional analysis of a peptidoglycan recognition protein involved in the immune response in the common cutworm, Spodoptera litura.

Peptidoglycan recognition proteins (GRPs) are family of pattern recognition receptors (PRRs), which can recognize the peptidoglycan and trigger the innate immune system against the microorganisms in insects. In this study, we identified a GRP-LB from Spodoptera litura genome database and named SlGRP-LB, which contained a complete open reading frame (ORF) of 639 bp, encoding a protein of 212 amino acids with a signal peptide and GRP domain. Phylogenetic tree analysis suggested that the SlGRP-LB has a close relationship with Helicoverpa armigera GRP-LB (HaGRP-LB). Tissue expression analysis revealed that SlGRP-LB had a high expression level in the fat body. The expression levels of SlGRP-LB were significantly upregulated in the hemolymph, fat body, and midgut from 3 to 12 h after injection of Escherichia coli and Staphylococcus aureus, while the expression levels were not downregulated at 24 h postinfection. Knockdown of SlGRP-LB expression by RNA interference reduced the expression of antibacterial peptide-related genes in the fat body and midgut, while their expression levels were upregulated in the hemolymph. In addition, the recombinant SlGRP-LB was expressed by using E. coli expression system, and it exhibited binding activity to E. coli. Taken together, the data suggest that S. litura GRP-LB might play a crucial role in regulating immune response in S. litura.

Validamycin treatment significantly inhibits the glycometabolism and chitin synthesis in the common cutworm, Spodoptera litura.

Validamycin, as a broadly applied antibiotic, has been used to control rice sheath blight disease. Furthermore, validamycin was considered as an insecticide to control agricultural pests. Insight into the mechanism of validamycin's action on insects can provide molecular targets for the control of agricultural pests. In this study, a toxicological test analysis revealed that Spodoptera litura larval growth and development was significantly inhibited and the pupation rate was significantly reduced with the increase of the concentration of validamycin. According to the NMR-based metabolomic analysis, a total of 15 metabolites involved in glycolysis and tricarboxylic acid cycle (TCA) pathways were identified. Additionally, trehalase activities, glucose and chitin contents were significantly downregulated, but the trehalose content was upregulated after exposure to validamycin. Reverse transcription quantitative PCR analysis revealed that the expression level of genes involved in glycolysis, TCA and chitin synthesis were upregulated after treating with validamycin. Further chitin staining also confirmed that chitin content was downregulated at 12 h after validamycin treatment. Our results indicated that validamycin worked via two different molecular mechanisms, one through inhibiting glycometabolism and the other by inhibiting chitin synthesis in S. litura. The information lays a theoretical foundation for further control of S. litura.