Search Results (67)

Ostrinia furnacalis is one of the most important agricultural pests in Asia. Previous studies utilizing 16S rRNA sequencing have established a foundational understanding of the taxonomic composition of its gut microbiota; however, the dynamic functional transitions across the host’s entire life cycle remain poorly understood. In this study, we used metagenomic sequencing to systematically characterize the gut microbiome across six groups representing different life stages and sexes of O. furnacalis: first-instar, third-instar, and fifth-instar larvae, pupae, and adults (both males and females). Microbial richness and evenness vary significantly across six groups representing different life stages and sexes. Species richness is highest in the first-instar larvae (L1D2), while evenness is relatively high in both first- and third-instar larvae (L1D2 and L3D2). Additionally, no sex-based differences were observed in either indicator during the adult stage. Enterococcus mundtii is the primary species driving community succession and rapidly achieves dominance after the third-instar stage. Co-occurrence network analysis revealed that the first-instar larval network exhibits the highest complexity, with positive correlations accounting for 96.6% of all edges. Conversely, the fifth-instar larvae exhibits the greatest proportion of negative correlation edges at 29.13%, while the pupal stage network is the most dispersive, indicating microbial reorganization during metamorphosis. Functional annotation reveals that carbohydrate and amino acid metabolism pathways are significantly enriched during the larval stage. In contrast, the pupal stage is characterized by enrichment in environmental information processing and a notable increase in polysaccharide lyases (PLs). This shift indicates that the microbiota transitioned from degrading plant polysaccharides to foraging host-derived glycans. The number of resistance genes in the first-instar larvae is significantly higher than that in all other groups representing different life stages and sexes. Collectively, this study systematically reveals the dynamic succession patterns of the gut microbiome throughout the life cycle of O. furnacalis and provides a theoretical foundation for the development of microbiome-based pest management strategies. Full article

Oral secretions (OS) of the Asian corn borer (Ostrinia furnacalis) play pivotal roles in its interactions with host plants. To systematically characterize the composition and potential functions of OS, 245 functionally annotated proteins from O. furnacalis reared on artificial diet were identified using an integrated approach combining transcriptomics and liquid chromatography–tandem mass spectrometry (LC-MS/MS). Bioinformatics analyses were further performed to predict 16 effector proteins. Subsequent tissue-specific expression assays were conducted to quantify the transcriptional levels of genes encoding these effector proteins in salivary glands, guts, and residual tissues. Among these genes, OfGDH2, OfPero2, OfPero3, and OfCBP were highly expressed in salivary glands, OfGDH3, OfRGD, OfEST1, OfEST2, OfMET, and Offerrin showed high expression in guts, while OfSP34 was abundantly expressed in both salivary glands and guts. This study represents the first systematic characterization of the molecular profile of O. furnacalis OS, thereby laying a solid foundation for future investigations into the molecular mechanisms underlying the host adaptation of this pest. Full article

Although Telenomus remus is an important parasitoid of Spodoptera frugiperda, the chemical basis for its host selection behavior remains unclear. To elucidate the chemical basis of this behavior, this study combined behavioral ecology and chemical ecology methods to systematically investigate the host location and recognition behaviors of this wasp, as well as the semiochemicals that regulate these behaviors. In Y-tube olfactometer assays, T. remus exhibited a significantly stronger olfactory preference for eggs of S. frugiperda over those of S. litura (p < 0.05) or the non-host Ostrinia furnacalis. A total of 759 metabolites belonging to 11 categories were identified via metabolomics analysis, and principal component analysis (PCA) clearly distinguished between host eggs and non-host eggs. Analysis of differential metabolites revealed that the significantly upregulated metabolites in host eggs mainly included aldehydes, ketones and esters, followed by hydrocarbons, alcohols and amines. Subsequently, we screened and verified the effects of the significantly upregulated metabolites in host eggs compared with non-host eggs on the host-selection behavior of T. remus, including indole, 2-hexanol, and trans-1,2-dimethylcyclohexane, as well as 2-heptadecanone and n-nonadecane—two alkane compounds which are specifically upregulated on the surface of S. frugiperda eggs. Behavioral validation demonstrated that 2-hexanol exerted a significant repellent effect on T. remus, whereas trans-1,2-dimethylcyclohexane exhibited a significant attractive effect on the parasitoid wasp. Among the metabolites specifically upregulated in S. frugiperda eggs, 2-heptadecanone exhibited significant attractive activity at concentrations ranging from 0.1 to 1.0 mg/mL. This study is the first to report that the cycloalkane compound trans-1,2-dimethylcyclohexane acts as a potential broad-spectrum chemical marker for T. remus to recognize the eggs of host species belonging to the family Noctuidae, while 2-heptadecanone may further enhance its preference for the optimal host S. frugiperda. These findings provide novel candidate molecular targets for the development of behavioral regulators targeting egg parasitoids against S. frugiperda. Full article

Endophytic colonization by entomopathogenic fungi represents a promising sustainable pest management strategy. This study investigated the physiological and molecular effects of maize endophytically colonized by Beauveria bassiana (strain BbOFDH1-5) conidia and blastospores on the Asian corn borer, Ostrinia furnacalis. We evaluated larval development, protective enzyme activities, and subsequent susceptibility to the insecticide chlorantraniliprole, utilizing gut transcriptomic analysis to elucidate the underlying mechanism. Results demonstrated that larvae fed on maize colonized by either spore type, particularly blastospores, exhibited significantly reduced food consumption, body weight, and survival rates. Additionally, the activities of protective enzymes (SOD, POD, CAT) were markedly suppressed. Feeding on blastospore-colonized maize significantly increased larval susceptibility to chlorantraniliprole. Transcriptomic analysis revealed that this enhanced sensitivity is linked to the downregulation of detoxification-related genes, ABCC4, and the upregulation of stress-response genes such as HSP70. These findings confirm that B. bassiana blastospores can synergistically enhance the efficacy of chemical insecticides by impairing larval physiology and suppressing gut-associated resistance mechanisms, providing a novel basis for integrated pest management. Full article

The impacts of transgenic maize on non-target organisms serve as a crucial parameter for evaluating the environmental safety of transgenic maize. In the present study, feeding experiments were carried out on Euborellia annulipes Lucas (Dermaptera: Anisolabididae) using two types of diets: maize (DBN9936 and parental maize DBN318) and maize combined with maize borers Ostrinia furnacalis Guenée (Lepidoptera: Crambidae). The survival rate, body weight, body length, reproductive efficiency, and activities of the superoxide dismutase (SOD) and catalase (CAT) of the predator were monitored. Moreover, the residual concentration of exogenous protein in the bodies, eggs, and feces of the earwigs was measured. The experimental findings indicated that there were no significant disparities in the aforementioned indicators between the transgenic and non-transgenic maize treatment groups. Nevertheless, differences were detected between the maize treatment groups and the maize borer treatment groups, especially regarding egg production. The earwigs in the maize borer treatment groups produced significantly more eggs. Overall, the feeding experiments demonstrated that transgenic maize did not exert adverse effects on E. annulipes. Full article

Docking calculations in semi-automatic virtual screening mode have been performed using AutoDock Vina (5 × 5 × 5 nm grid box, centered on the chain A) and FYTdock helper software. N-hexanoyl ciprofloxacin has been found to bind with chitinases from Ostrinia furnacalis (pdb codes: 7vrg, 6jaw, 6jay, 6jmn, 5y2b; energy of bindings (Ebind) −10.2…−9.7). N-hexanoyl-N’-NBD-piperazine, and NpipHex bind in silico with the enzyme less effectively (pdb codes: 6jaw, 5y2b, 6jay, 5y2c, 3wkz; Ebind −9.3…−8.9). Lipid-like N-NBD-oleylamine and N-Dansyl-oleylamine demonstrated quite similarly, but smaller affinity (Ebind −8.6…−8.0). Examples of interactions close to the active sites of the chitinases were found for all compounds. These results provide new insights into insect biochemistry of chitinases showing new molecular scaffolds suitable as prototypes of tools for pest control or fluorescence-based screening. Full article

Transgenic Bt maize commercialization has become a critical pest management strategy against lepidopteran insects in southwest China, but its ecological impact on arthropod biodiversity remains insufficiently characterized. This two-year field investigation (2023–2024) conducted in Bazhong City, Sichuan Province utilized systematic field monitoring to compare arthropod community dynamics between conventional maize and Bt-Cry1Ab maize (DBN9936) cultivation systems. This study documented 575,970 arthropod specimens representing 80 species/types across 45 families and 17 orders. Analysis of variance revealed significant differences (p < 0.05) between non-Bt and Bt maize in the abundance and species richness of target herbivorous pests, non-target herbivorous pests, and natural enemy insects. Field investigations revealed a notable absence of Macrocentrus cingulum, a key larval parasitoid of Ostrinia furnacalis, in Bt-maize plots compared to conventional counterparts. The populations of non-target herbivorous pests and natural enemies such as Aphididae, Chrysoperla sinica, Frankliniella tenuicornis, and Orius sauteri were higher in Bt maize fields than in non-Bt maize fields, while the populations of target herbivorous pests including O. furnacalis and Mythimna loreyi were lower than those in non-Bt maize fields. However, no significant differences (p > 0.05) were observed in arthropod abundance, species richness, or in a suite of ecological indices including the Simpson diversity index, Shannon–Wiener diversity index, Pielou evenness index, McIntosh diversity index, and community stability indices (N_n/N_p, N_d/N_p, and S_d/S_p). Redundancy analysis identified maize growth stages (6.75% variance explained) and interannual variations (2.44%) as principal drivers of arthropod community dynamics, with maize genotype contributing minimally (1.53%). These findings demonstrate that Bt-Cry1Ab maize (DBN9936) cultivation maintains functional arthropod community structure while effectively controlling target pests, providing substantial empirical evidence to support its sustainable deployment in southern China’s agricultural landscapes. Full article

Transgenic insect-resistant maize can effectively control insect pests, which is of great significance to improve maize yield and quality. Transgenic maize LD05 is an insect-resistant and herbicide-tolerant maize independently developed by Shandong Academy of Agricultural Sciences and highly resistant to major lepidopteran pests. In order to study the pest resistance of transgenic maize LD05 in different ecological areas of China, this study conducted a laboratory bioassay, and artificial inoculation test and natural pest investigation in field were carried out in one pilot of each of five maize ecological zones in China. The results of laboratory bioassay showed that transgenic maize LD05 had high resistance to Ostrinia furnacalis (Guenée), Mythimna separata (Walker), Helicoverpa armigera (Hübner) and Spodoptera frugiperda (J. E. Smith), the main lepidopteran pests threatening maize production in China. The results of artificial inoculation test and natural pest investigation in field showed that transgenic maize LD05 had high resistance to major lepidopteran pests in different ecological areas of China, which was consistent with the pest resistance management strategy, and can provide important theoretical basis and technical support for the industrialization of transgenic maize LD05 in the future. Full article

This study evaluated the effects of red and blue laser irradiation on the development and reproduction of the Asian corn borer (Ostrinia furnacalis (Guenée)) under controlled laboratory conditions, aiming to explore its potential for non-chemical pest control. Larvae were exposed to laser light at different wavelengths and intensities, and key biological parameters—including egg hatching, larval duration, pupation, adult emergence, and oviposition—were assessed. Red laser light slightly delayed egg hatching but had minimal effects on subsequent developmental stages. In contrast, blue laser irradiation significantly prolonged the larval period and reduced pupation rates. Combined red–blue treatments produced similar inhibitory effects to blue light alone, suggesting that blue wavelengths were the primary factor driving developmental delays. These findings demonstrate that blue and red–blue laser irradiation can effectively interfere with the life cycle of O. furnacalis, offering a promising approach for sustainable, light-based pest management strategies. Full article

Bacillus thuringiensis (Bt) is an efficacious biocontrol bacterium known for producing various toxins, such as crystal toxins, which disrupt the midgut epithelium of pest larvae, leading to larval mortality. However, the development of resistance to Bacillus thuringiensis in pests poses a significant threat to the widespread application of Bt corn. Consequently, we employed high-throughput sequencing of the midgut bacterial 16S ribosomal RNA to characterize the midgut bacteria in four Bt-resistant strains. Specifically, Bt-resistant strains (ACB-FR and ACB-AcR) exhibited lower bacterial diversity compared to ACB-AbR and ACB-IeR. Multivariate analyses and statistical evaluations further demonstrated that the microbiota communities in Bt-resistant pests (AbR, AcR, IeR, and FR) were distinct from those in Bt-susceptible strains. Notably, the genus Klebsiella predominated in BtS, whereas Enterococcus was the genus with peak enrichment in AbR, AcR, IeR, and FR. Bioassays subsequently revealed that Enterococcus enhances the Cry1Ab resistance of ACB larvae. Our investigations indicate that treatment with Bt protein alters the midgut microbiota community of O. furnacalis, and these microbiota differences may potentially modulate the Bt-induced lethality mechanism. Full article

ZDRF-8 is a transgenic maize event created via Agrobacterium-mediated transformation for insect resistance and glyphosate tolerance by expressing Cry1Ab, Cry2Ab, and G10evo-epsps. A Southern blot analysis suggested that it is a single-copy T-DNA insertion event. The flanking genomic sequences of the T-DNA insertion suggested that its T-DNA was inserted at the terminal region of the long arm of chromosome 7 without interrupting any known or predicted genes. Event-specific PCRs based on the flanking sequence were able to detect this event specifically. Laboratory bioassays and field trials of multiple generations demonstrated that ZDRF-8 is highly active against major corn pests in China, including Asian corn borers (ACB, Ostrinia furnacalis), cotton bollworms (CBW, Helicoverpa armigera), and oriental armyworm (OAW, Mythimna separata), and meanwhile confers glyphosate tolerance up to two times the recommended dose. The expression of the transgenes and the efficacy of insect resistance and glyphosate tolerance were stable over more than 10 generations. ZDRF-8 has been granted with a safety certificate in China, and its commercial release is expected in the coming years. Full article

In China, the Asian corn borer (ACB), Ostrinia furnacalis (Guenee) (Lepidoptera: Pyralidae), is the most significant economic insect pest of corn, causing losses ranging from six to nine million tons annually by feeding on all parts of maize, including damaging ears and leaves and making tunnels in stems. In China, since the 1970s, the Trichogramma species have extensively mass-reared from factitious hosts to control ACB and support integrated pest management programs. The Trichogramma dendrolimi Matsumura and T. ostriniae Pang and Chen are the most efficient biocontrol agents for controlling ACB among the available Trichogramma species. To evaluate the reproductive success of Trichogramma dendrolimi and T. ostriniae, we assessed the impact of varying parasitoid ratios (5:1, 3:1, 1:1, 1:3, and 1:5 representing T. dendrolimi and T. ostriniae, respectively) on adult offspring emergence and mortality from ACB eggs over multiple generations (from first (F₁) to third (F₃) generations). We discovered that both Trichogramma species’ offspring emergence was significantly influenced by the parasitoid generations, parasitoid ratios, and their interactions. The offspring mortality in both Trichogramma species was significantly affected by parasitoid generations but was not significantly influenced by parasitoid ratios or interaction between parasitoid generations and parasitoid ratios. Furthermore, at parasitoid ratios of 5:1, 3:1, and 1:1, the emergence rate of the F₁ generation of T. dendrolimi was significantly higher compared to the ratios of 1:3 and 1:5. However, in the F₂ generation, the emergence of T. dendrolimi decreased considerably, and no emergence was observed in the F₃ generation. A contrasting trend was observed in the emergence of T. ostriniae offspring. Overall, regardless of the parasitoid ratios, the offspring emergence of T. ostriniae in all three generations was significantly higher than that of T. dendrolimi. After assessing the offspring mortality in our research by dissecting the unhatched eggs, we found an inverse relationship between the T. dendrolimi generations and their mortality across different parasitoid ratios. Notably, mortality exhibited a significant decline with an increasing number of generations. A positive correlation was observed between the number of T. ostriniae generations and their mortality across different parasitoid ratios, indicating that mortality increased with successive generations. Overall, across all parasitoid ratios and generations, the offspring mortality of T. ostriniae was considerably greater than that of T. dendrolimi. These results suggest that mortality is a crucial empirical measure that validates T. ostriniae’s superiority over T. dendrolimi. These findings highlight the importance of selecting suitable parasitoid species when implementing Trichogramma for pest management. Full article

Nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) play crucial roles in the development and pathogenicity of the entomopathogenic fungus Beauveria bassiana. However, they are among the few biosynthetic gene clusters with unknown functions in B. bassiana. To investigate the role of the hybrid PKS–NRPS synthetase gene BBA_09856 in B. bassiana, we constructed a mutant strain, ∆BBA09856-WT, by deleting the BBA_09856 gene through Agrobacterium-mediated transformation. We then analyzed the biological characteristics of the mutant strain and the virulence of the mutant strain toward Ostrinia furnacalis larvae, as well as its antagonistic effects against the phytopathogen Botrytis cinerea. We found that the average growth rate of the three mutant strains, ∆BBA09856-WT, was significantly higher compared to the wild-type (WT) strain on the 15th day of culture on potato dextrose agar (PDA) plates (7.01 cm vs. 6.30 cm, p < 0.01). Additionally, the average spore production(3.16 × 10⁷/cm² vs. 9.95 × 10⁶/cm², p < 0.001) and germination rate (82.50% vs. 54.72%, 12 h, p < 0.001) were significantly different between the three mutant strains, ∆BBA09856-WT, and the WT strain. The average survival rates of O. furnacalis infected with the WT strain and the three mutant strains, ∆BBA09856-WT, after 8 days were 61.66%, and 30.00%, respectively, indicating that the pathogenicity of the tested mutant strains was significantly greater than that of the WT strain. The results of the dual culture test indicated that the inhibitory rates of the WT and ∆BBA09856-WT strains against B. cinerea were 40.25% and 47.65%, respectively (p < 0.001). Similarly, in the dual culture test, the WT strain reduced the growth of B. cinerea by 9.90%, while the ∆BBA09856-WT exhibited a significantly greater inhibition rate of 28.29% (p < 0.05). The diameters of disease spots, measured 6 d after inoculation with B. cinerea in the tomato treatment groups, revealed significant differences in endophytic colonization between the WT and ∆BBA09856-WT strains in the WT+Bc and ∆BBA09856-WT+Bc treatment groups (15.26 mm vs. 12.16 mm, p < 0.01). Notably, ∆BBA09856-WT exhibited enhanced virulence toward O. furnacalis larvae and increased antagonistic activity against B. cinerea. Our results indicate that the gene BBA_09856 may have a negative correlation with the development and virulence of B. bassiana toward the insect pest O. furnacalis larvae, as well as its antagonism against B. cinerea. These findings suggest that molecular techniques, such as gene editing, could be employed to develop superior strains of B. bassiana for the biological control of plant diseases and insect pests. Full article

Asian corn borer (ACB), Ostrinia furnacalis, is a predominant pest species that is widely distributed across major corn-growing regions in China. Tetraniliprole, a novel diamid insecticide, exhibited good efficacy on lepidopteran insect pests and was officially sanctioned for controlling ACB in China. In this study, a tetraniliprole-resistant strain called ACB-TLR was obtained from a susceptible strain, ACB-SS, after 10 continuous generation selections with tetraniliprole. Additionally, the fitness cost of the ACB-TLR strain was assessed. The results showed that ACB developed 11.58-fold resistance to tetraniliprole and the realized heritability was estimated as 0.213. The ACB-TLR strain displayed 2.10 times cross-resistance to chlorantraniliprole, but we found no cross-resistance to emamectin benzoate and deltamethrin. The development time of larvae and pupae was significantly prolonged, the adult longevity was significantly shorter, and the pupation and emergence rates were significantly reduced in the ACB-TLR strain than in the ACB-SS strain, with a relative fitness of 0.39. The current study indicated that ACB has the potential to develop resistance to tetraniliprole in the field. However, the decreased fitness may allow insecticide resistance to be managed. Full article