Search Results (127)

[Objective] To determine the control potential of Arma chinensis against major soybean pests Helicoverpa armigera and Spodoptera exigua, thereby providing theoretical and practical support for biological pest control in soybean fields. [Methods] Laboratory and field experiments were conducted to assess the predation capacity, feeding preference, and field control effect of third~fifth-instar nymphs and male/female adults of A. chinensis on first, third and fifth-instar larvae of these two pests. Predation functional responses were fitted to analyze predation characteristics and the relationship between searching efficiency and prey density. [Results] Both nymphs and adults of A. chinensis preyed on the larvae of H. armigera and S. exigua, with the predation functional responses conforming to the Holling Type II disk equation, which presented the highest predatory efficiency. The female adult of A. chinensis showed strong predation capacity against H. armigera (55.368) and S. exigua (50.699) larvae, with the highest daily prey consumption of 13.158 and 13.699 individuals, respectively. Searching efficiency of A. chinensis was negatively correlated with prey density, and significantly higher for first-instar than third-instar larvae. Under cooccurrence conditions, A. chinensis displayed an obvious feeding preference for H. armigera larvae. Field trials demonstrated that female adults of A. chinensis generated a 70% population decline rate of H. armigera. Meanwhile, the population decline rate of S. exigua reached over 80%. Female adults of A. chinensis achieved field control rates of 80% against H. armigera larvae and 70% against S. exigua larvae. [Conclusions] A. chinensis has strong predation and control potential against the larvae of H. armigera and S. exigua. Among these, females of A. chinensis demonstrated the highest efficacy in controlling the two types of Lepidoptera larvae, both indoors and in field conditions. It is a promising biological control agent for soybean fields and provides a scientific basis for large-scale application. Full article

Apolygus lucorum (Meyer-Dür) is a phytozoophagous crop pest. While the effects of plant-based diets on its development and reproduction have been extensively studied, the combined effects of plant- and prey-based diets on these traits remain poorly understood. This study systematically evaluated the effects of plant-only, prey-only, and mixed plant–prey diets on A. lucorum nymphal survival and development, as well as adult longevity and fecundity, under controlled laboratory conditions. The results demonstrate that diet composition significantly affected nymphal survival and developmental progression. Nymphs fed exclusively on prey (Aphis gossypii Glover or Bemisia tabaci (Gennadius) nymphs) failed to complete juvenile development. Although a diet of Helicoverpa armigera (Hübner) eggs alone enabled some individuals to reach adulthood, survival rates were significantly lower than those in mixed-diet treatments. Mixed feeding markedly improved nymphal survival, with the highest rates observed in groups fed green beans + H. armigera eggs and cotton leaves + B. tabaci nymph combinations (both 64.45%). The developmental duration was also influenced. Mixed diets, particularly green beans + H. armigera eggs, significantly shortened each instar and the total developmental time (11.04 ± 0.17 d), whereas a diet of cotton leaves alone prolonged development (19.45 ± 0.24 d). Adult longevity and reproductive output were likewise diet-dependent. The longest lifespans were recorded in adults fed green beans alone or green beans + H. armigera eggs, while the shortest lifespan was observed for those fed only cotton leaves. Successful oviposition was only achieved following four dietary treatments: green beans alone, green beans + H. armigera eggs, H. armigera eggs alone, and cotton leaves + H. armigera eggs. Among these, the green bean + H. armigera egg diet yielded the best reproductive performance, featuring the shortest pre-oviposition period (5.82 ± 0.60 d), the longest oviposition period (19.41 ± 1.68 d), and the highest mean fecundity per female (238.35 ± 25.51 eggs). This underscores the reproductive advantage of a mixed plant–prey diet. This study clarifies how dietary conditions shape the survival, development, and reproduction of A. lucorum, highlighting its strong reliance on nutritional quality for key life-history traits. These findings offer valuable insights into the ecological adaptations underlying the feeding behavior of this insect. Full article

Lipopolysaccharide-induced tumor necrosis factor alpha factor (LITAF) as a crucial cytokine can mediate the inflammatory and immune regulatory responses of an organism. It plays a significant mediatory role in the innate immune system of insects. Firstly, the LITAF family of cotton bollworm (Helicoverpa armigera, Lepidoptera: Noctuidae) was analyzed, and the differentially expressed genes of HaLITAFs were screened from the 2-tridecanone-treated transcriptome. Subsequently, these two differentially expressed HaLITAF genes were cloned and analyzed, and the effect of different larval stages, tissues, and plant secondary metabolites on their gene expression were detected in H. armigera. The cotton bollworm contains 13 LITAF genes, and there are no repetitive sequences among them. Upon 2-tridecanone treatment, only HaLITAF5 and HaLITAF7 were significantly upregulated in the LITAF family of cotton bollworm larvae after 6 h. The HaLITAF5 and HaLITAF7 proteins, respectively, comprised 78 and 113 amino acids, and both contained a CXXC motif, hydrophobic amino acid region and HXCPXCXXXXG motif. Both of them belong to the LITAF analogues (zf-LITAF-like) superfamily. The expressions of HaLITAF5 and HaLITAF7 were both the lowest in fourth-instar larvae and the highest in sixth-instar larvae, and both were abundantly expressed in the midgut of sixth-instar larvae. Following a 28 h treatment with 2-tridecanone, the expression levels of HaLITAF5 and HaLITAF7 peaked. HaLITAF7 exhibited the highest expression level after a 4 h exposure to tannic acid, whereas HaLITAF5 reached its peak after 28 h of tannic acid treatment. The maximum expression levels of HaLITAF5 and HaLITAF7 were observed after 28 h and 4 h of quercetin treatment, respectively. Subsequent to ZQ-8 treatment, HaLITAF5 expression peaked at 28 h, while HaLITAF7 expression peaked at 8 h. Both HaLITAF5 and HaLITAF7 were overexpressed after different kinds of plant secondary metabolite stresses, and thereby, they may be regulated in the expression of genes related to downstream detoxification metabolic processes. This provides a theoretical foundation for further studies on the functional mechanism of the LITAF gene in H. armigera. Full article

Diapause is a vital overwintering strategy for many insects, yet its comprehensive molecular architecture remains elusive. In the polyphagous pest Helicoverpa armigera, facultative pupal diapause is key to its ecological success. To elucidate the complex diapause regulatory network, we conducted a transcriptomic analysis of diapause (DP) versus non-diapause (NP) pupal brains across early pupal development (days 2, 5, and 10). Integrated analyses, including differential expression, persistent gene identification, weighted gene co-expression network analysis (WGCNA), and multiscale embedded network analysis (MEGENA), were employed to define core regulatory modules and hubs. The number of differentially expressed genes (DEGs) increased over time, with 1781 genes persistently regulated across all time points, enriched in mitochondrial metabolism, hormone signaling, and chromatin remodeling. WGCNA revealed a diapause-associated module (red) linked to RNA processing/transcription and a development-associated module (blue) enriched for translation and mitochondrial metabolism. Network analyses pinpointed three central hub genes: DDX5 and PLK4 (downregulated in diapause, upregulated upon 20E treatment) and TAF5L (upregulated in diapause, downregulated after 20E). This study provides a systems-level view of the transcriptional landscape governing pupal diapause in H. armigera and identifies novel candidate regulators for future functional studies. Full article

Despite the central role of the gustatory nervous system in regulating feeding behavior in the larvae of the major agricultural pest Helicoverpa armigera, the systemic molecular basis of this process is largely unknown. To investigate the molecular basis, we performed RNA-seq on dissected brains and gnathal ganglion (GNG) from fifth-instar larvae, revealing 944 differentially expressed genes (DEGs) that are potentially involved in feeding behaviors. Bioinformatic analyses revealed significant enrichment of these DEGs in pathways including “taste transduction”, “neuroactive ligand–receptor interaction”, and “feeding behavior”. Furthermore, 41 candidate genes closely associated with feeding behaviors were screened, including neuropeptides, neuropeptide receptors, gustatory receptors, and feeding-mediated proteins. Phylogenetic analyses demonstrated that these key genes are evolutionarily conserved. Quantitative real-time PCR (qPCR) results confirmed that most of these candidate genes were significantly upregulated during the fifth instar stage, and their expression was further enhanced under starvation conditions (p < 0.05). Our study presents the first systemic feeding-mediated transcriptomic profile in the insect central nervous system and identifies key feeding-mediated genes in H. armigera larvae. These findings advance our understanding of the molecular basis of feeding in Lepidopteran pests and offer potential target genes for developing gustatory-based pest control strategies. Full article

The cotton bollworm (Helicoverpa armigera, Lepidoptera: Noctuidae) is a globally distributed agricultural pest. When conducting expression analysis of its functional genes, appropriate reference genes should be selected to ensure the reliability of the results. In this study, five algorithms including Delta Ct, GeNorm, Normfinder, BestKeeper, and RefFinder were used to evaluate the expression stability of eleven candidate reference genes under different developmental stages, larval tissues, adult sexes, plant secondary substance stresses, and insecticide treatments in H. armigera. The candidate genes included Actin, Tubulin, EF-1α, RPS3, RPS15, RPL27, RPL32, 28S, GAPDH, SOD, and TRX. The reliability of the recommended reference gene combinations was validated using the growth arrest and DNA-damage-inducible gene 45 (GADD45). The results showed that normalizing relative expression of the target gene with the combination of the two most stable reference genes is recommended. Specifically, the combination of RPS3 + RPL27 is recommended for developmental stage comparisons; RPL32 + RPL27 for larval tissues; RPS3 + RPL27 for adult sex comparisons; GAPDH + RPL32 under tannic acid stress; RPL32 + RPS3 under quercetin stress; RPS15 + RPL32 under 2-tridecanone stress; RPS3 + RPL32 under ZQ-8 stress; RPL27 + TRX following chlorantraniliprole treatment; and RPL27 + RPL32 following indoxacarb treatment. Moreover, larvae exposed to three concentrations of plant secondary substances and to sublethal doses of insecticides exhibited significant upregulation of GADD45: after 4 h of exposure to 1% tannic acid, 0.1% and 1% quercetin, 1% 2-tridecanone, and 0.05% ZQ-8; after 15 h of chlorantraniliprole treatment; and after 24 h of indoxacarb treatment. Thus, GADD45 was overexpressed in response to various plant secondary substances and insecticide treatments, indicating its involvement in the detoxification and metabolism of H. armigera. This study proves to be helpful for selecting reference genes in H. armigera under plant secondary substance and insecticide stress and lays the foundation for further research utilizing GADD45 as a molecular target for pest control. Full article

The cotton bollworm, Helicoverpa armigera (Hübner), a cosmopolitan agricultural pest, inflicts severe impacts on global agriculture. As a poikilotherm, it was highly susceptible to climate change, yet critical gaps persist in understanding how its sensitivity interacts with climatic shifts—knowledge essential for integrated pest management (IPM). We, therefore, analyzed H. armigera’s susceptibility to temperature variations using long-term pest population and meteorological data from Maigaiti and Bachu Counties (southern Xinjiang) and Shawan County (northern Xinjiang). The results showed H. armigera populations increased overall, with reduced interannual fluctuation magnitude. The main meteorological factors influencing the interannual population changes of H. armigera in Maigaiti, Bachu, and Shawan were T_max difference in winter (98.0%), T_min difference in May (80.7%), and T_min difference in July (99.4%), respectively. Higher winter temperature (particularly February) reduced the spring population sizes across all three regions, with only the population in Bachu showing a significant correlation. For annual populations, warmer winter caused a significant decline in Bachu, a marked increase in Maigaiti, and a non-significant rise in Shawan. Summer temperature below 33 °C boosted populations in all regions; above 33 °C, the Maigaiti population declined non-significantly, while the Bachu population dropped significantly. Climate warming advanced the pest’s first appearance, delayed its disappearance, and extended its active period, increasing population size—a trend projected to intensify in the future. Maigaiti and Shawan populations were governed by T_max in winter and T_min in July, respectively, whereas the Bachu population was constrained by temperature differences during multiple key growth and development periods throughout the year. These divergent regulatory patterns and climatic responses reflect varying vulnerability levels, providing a theoretical basis for targeted H. armigera control. Full article

Gene editing technologies are playing an increasingly important role in the study of insect gene functions. Appropriate incubation humidity helps improve the hatching rate of insect eggs. However, to date, no study has evaluated the impact of humidity on the hatching rate of gene-edited eggs or the subsequent development of the larvae. Using the cotton bollworm Helicoverpa armigera (Lepidoptera: Noctuidae) as a model, we investigated the weight and hatching rate of microinjected eggs under different humidity conditions. We determined the larval development time and pupal weight and calculated the larval gene editing efficiency. The results showed that post-microinjection incubation under high humidity (RH = 95%) had a significant influence on CRISPR/Cas9 gene-edited eggs. The key research results indicate that, compared with the incubation environment with RH ≤ 80%, after 48 h of incubation under 95% RH, the hatching rate of H. armigera eggs increased by more than 27.5%, with higher egg saturation and greater egg weight; meanwhile, the larval developmental duration was shorter and the pupal weight was also greater. These results establish a humidity-regulated developmental recovery protocol for gene-edited insects, which provides theoretical and practical support for optimizing post-microinjection recovery processes in gene-edited insects. Full article

Entomopathogenic fungi are among the most promising non-chemical alternatives for the control of many serious phytophagous insect pests, such as moth species. The present research investigates the use of the little-studied entomopathogenic fungus Beauveria varroae as a biocontrol agent against the notorious pests Helicoverpa armigera and Sesamia nonagrioides in laboratory conditions. Conidial suspensions of B. varroae were prepared at 10³-10⁴-10⁵-10⁶-10⁷-10⁸ conidia/mL to assess their insecticidal potential. In this study, we used 100 3rd-instar larvae for each concentration. During the lab bioassays, almost complete mortality of 35–96.6% was recorded for H. armigera larvae and 40–96.6% for S. nonagrioides larvae 10 days after exposure. The lethal effect of the entomopathogen was related to both dose and exposure time of the entomopathogen, with higher concentrations resulting in increased mortality. The survival effect of S. nonagrioides and H. armigera larvae was dependent on the hazard effect of the used dose and the exposure time. These findings indicate that B. varroae has potential as a biocontrol agent. Further research will elucidate this new isolate and optimize application methods in field conditions. Full article

The moth Helicoverpa armigera (Lepidoptera: Noctuidae), better known as the pod borer, poses significant threats to chickpea (Cicer arietinum L.) production. Therefore, effective and sustainable crop management strategies are required to mitigate the impact of this cosmopolitan pest. The present study aimed at investigating the potential of wood distillate (WD), a liquid byproduct of the pyrolysis of waste lignocellulosic biomass, to both reduce H. armigera pest incidence and to enhance crop yields in field-grown chickpea. The application of WD as a foliar spray effectively reduced the number of damaged pods by 35% during the plant´s reproductive stage compared with water-sprayed plants (~16 vs. 24 bored pods plant⁻¹, respectively) and increased the number of healthy pods (~16 vs. 10 pods plant⁻¹, respectively). Moreover, the lower pest incidence was accompanied by an improvement of both the seed yield and the quality at the plant´s full maturity stage. Specifically, WD-treated plants increased both the number and weight of seeds by ~80% compared to water-sprayed plants (~23 vs. 13 and 5.5 vs. 3 plant⁻¹, respectively) which further showed a remarkable improvement in their nutritional value, with the concentration of total polyphenols, flavonoids, starch, calcium, and magnesium increasing by 17%, 56%, 43%, 23%, and 15%, respectively. These results underscore the potential of WD to both improve chickpea performance and to reduce H. armigera damage to sustainably improve the productivity of this critical legume crop, aligning with the principles of the circular economy and offering an environmentally friendly alternative to synthetic pesticides and fertilizers in agriculture. Full article

The use of insect sex pheromones as an alternative technology for pest control in agriculture and forestry offers a promising solution. The development of a novel technology for the biological production of pheromones through yeast fermentation significantly lowers production costs, enabling the adoption of sustainable pest control practices in field crops, a strategy previously reserved for high-value crops. Over three years of monitoring and mating disruption trials in Greek cotton fields, focusing on the cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), it was confirmed that yeast-derived pheromones exhibit equal efficacy compared to their chemically synthesized counterparts. For the mating disruption of H. armigera, a biodegradable, flowable, and paraffin-based matrix was developed. The matrix adheres to plants, protects the labile pheromone molecules (Z)-11-hexadecenal and (Z)-9-hexadecenal, and controls their gradual release into the environment. These biodegradable polymer blobs act as non-retrievable dispensers and can be deployed manually or via unmanned aerial vehicles (UAVs), ensuring efficient and accurate application. This precise, time-efficient, and economically sound technology aligns with European Commission initiatives, such as the Green Deal’s Farm to Fork Strategy and the Biodiversity Strategy, contributing to food sustainability while respecting biodiversity. Full article

The ichneumonid parasitoid Campoletis chlorideae is an important natural enemy of lepidopteran pests in different agro-ecosystems, specifically targeting early larvae (second- and third-instar). Enhancing the survival of C. chlorideae, especially within hosts, remains a significant technical challenge for large-scale indoor reproduction. This study investigates the use of endogenous serpin-e protein, derived from the host Helicoverpa armigera (Haserpin-e), to improve the survival rate of C. chlorideae in indoor reproduction. The results demonstrated that Haserpin-e protein significantly enhanced cocoon production in C. chlorideae, with no observable adverse effects on the life history traits of both F0 and F1 generations of C. chlorideae. By investigating the mechanism underlying cocoon formation promotion, it was found that Haserpin-e protein reduced the encapsulation, inhibited melanization, as well as suppressed the expression of antimicrobial proteins (AMPs) in H. armigera. This study provides novel insights into improving the survival of C. chlorideae by inhibiting host immune responses through the application of its endogenous Haserpin-e protein during large-scale indoor reproduction efforts. Additionally, this research further elucidates the multifaceted functionality of Haserpin-e proteins by demonstrating their role in regulating innate immune processes in H. armigera, including negatively regulating encapsulation, melanization, and AMP expression. Full article

The development of an effective artificial diet is essential for the mass rearing of insects used in pest management programs, including augmentative biological control, insecticide resistance monitoring, and sterile insect release. This study evaluated the consumption, utilization, and enzymatic responses of the polyphagous pest Helicoverpa armigera (Hübner, 1808) (Lepidoptera: Noctuidae) when reared on meridic diets supplemented with different pollen grains. The control diet followed a well-established meridic formulation, while the eight experimental diets incorporated pollen from the honey bee, rapeseed, maize, sunflower, hollyhock, glossy shower, saffron, and date palm. The findings indicate that pollen supplementation enhances the quality of artificial diets for H. armigera. Larvae fed on the date palm pollen-supplemented diet exhibited significantly higher weight gain, efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), and relative growth rate (RGR) compared to those fed on the control diet. The highest relative consumption rate (RCR) was observed in larvae fed on the sunflower pollen-supplemented diet. Additionally, pollen-supplemented diets influenced the amylolytic and proteolytic enzyme activities of H. armigera larvae in a diet-dependent manner. Nutritional analysis of the pollen types revealed significant variations in the sugar, lipid, and protein contents. Cluster analysis further identified the date palm pollen-supplemented diet as the most nutritionally beneficial, suggesting its potential application in the large-scale production of H. armigera. Full article

A series of novel triazone derivatives containing aldehyde hydrazone or ketone hydrazone moieties were designed, synthesized and their biological activities were investigated against Aphis craccivora, Culex pipiens pallens, Helicoverpa armigera, Ostrinia nubilalis, Mythimna separata and 14 Kinds of fungi. Most of the aldehyde hydrazone exhibited excellent insecticidal activities against A. craccivora. In particular, the aphicidal activities of compounds 3t (35%) and 3w (30%) were equivalent to pymetrozine (30%) at 5 mg/kg. The aphicidal activities of derivatives 3p, 3u, 3y, 5g, 5i, 5l, 5q and 5u against C. pipiens pallens were higher than that of pymetrozine. Compound 3u (100%) exhibited good larvicidal activities against C. pipiens pallens at 0.25 mg/kg. Most derivatives exhibited broad-spectrum fungicidal activities against 14 kinds of plant fungi at 50 mg/kg. Thirty-nine compounds exhibited a more than 50% inhibition rate against Physalospora piricola. Compounds 3h, 3t and 3w were expected to be the leading structure for the development of new triazone insecticides agents. Full article

Cry2Ab is a significant alternative Bacillus thuringiensis (Bt) protein utilized for managing insect resistance to Cry1 toxins and broadening the insecticidal spectrum of crops containing two or more Bt genes. Unfortunately, the identified receptors fail to fully elucidate the mechanism of action underlying Cry2Ab. Previous studies have demonstrated the involvement of vacuolar H⁺-ATPase subunits A, B, and E (V-ATPase A, B, and E) in Bt insecticidal activities. The present study aims to investigate the contribution of V-ATPase C to the toxicities of Cry2Ab against Helicoverpa armigera. The feeding of Cry2Ab in H. armigera larvae resulted in a significant decrease in the expression of V-ATPase C. Further investigations confirmed the interaction between V-ATPase C and activated Cry2Ab protein according to Ligand blot and homologous and heterologous competition assays. Expressing endogenous HaV-ATPase C in Sf9 cells resulted in an increase in Cry2Ab cytotoxicity, while the knockdown of V-ATPase C by double-stranded RNAs (dsRNA) in midgut cells decreased Cry2Ab cytotoxicity. Importantly, a higher toxicity of the mixture containing Cry2Ab and V-ATPase C against insects was also observed. These findings demonstrate that V-ATPase C acts as a binding receptor for Cry2Ab and is involved in its toxicity to H. armigera. Furthermore, the synergy between V-ATPase C protein and Cry2Ab protoxins provides a potential strategy for enhancing Cry2Ab toxicity or managing insect resistance. Full article