The invasive fall armyworm Spodoptera frugiperda and other lepidopteran migratory pests significantly threaten maize production in tropical Asia, a key year-round breeding region and source of spring or summer migrants across the broader Asian region. The strategic deployment of genetically modified maize expressing pyramided Bacillus thuringiensis (Bt) toxins offers a promising approach for managing multiple pests and delaying resistance evolution in this region. This study evaluated the insecticidal efficacy of Bt maize (LP026-2 event, Cry1Ab + Cry2Ab + Cry1Fa) against six major lepidopteran pests: S. frugiperda, Mythimna separata, Spodoptera exigua, Spodoptera litura, Helicoverpa armigera, and Ostrinia furnacalis. Total Bt protein levels in Bt-(Cry1Ab + Cry2Ab + Cry1Fa) maize followed the order: leaf > silk > kernel, with Cry2Ab as the dominant toxin, comprising 84.49% (188.75 μg g-1) in leaves and 64.12% (16.12 μg g-1) in kernels. Bioassays demonstrated its high efficacy, with corrected mortality >90% against all six pests in leaf and kernel assays after 5 days. Pest susceptibility ranked as H. armigera > S. frugiperda > O. furnacalis > M. separata > S. exigua > S. litura, with efficacy highest in leaf, followed by kernel and silk tissues (silk mortality 69.15-98.94%). Field trials further validated the efficacy of Bt maize, showing significant reduction in larval densities, plant damage, along with 4.52-25.41% yield increase over the non-Bt maize. These findings demonstrate that Bt-(Cry1Ab + Cry2Ab + Cry1Fa) maize provides effective multi-pest control and yield benefits, supporting its integration into the migratory pest management strategies for tropical maize production systems. © 2025 Society of Chemical Industry.

Notch regulates mitochondrial activity in pupal diapause of Helicoverpa armigera through the c-Myc-TFAM pathway.

Comprehensive toxico-physiological evaluation of Melia azedarach methanolic fruit extract on Helicoverpa armigera larvae: Developmental delay, nutritional disruption, enzymatic modulation and midgut histology

HaGATAe regulates chitin synthase 2 and insect intestinal mucin expression with ecdysone responsive transcription factors in Helicoverpa armigera.

Groundnut (Arachis hypogaea L.) is a major oilseed crop globally, but its productivity is severely affected by polyphagous pests such as Spodoptera litura Fab. and Helicoverpa armigera Hub. (Lepidoptera: Noctuidae). These lepidopteran pests cause significant damage to foliage, resulting in yield losses. Silicon (Si), an abundant element in the Earth's crust, is increasingly recognized for its role in enhancing plant resistance to biotic stress. This study aimed to evaluate the impact of calcium silicate supplementation on the developmental biology and nutritional physiology of S. litura and H. armigera larvae feeding on groundnut leaves. Groundnut plants were treated with calcium silicate via foliar spray (2.0%, 3.5%, 5.0%), soil drenching (10%, 15%, 20%) and combined applications. Larval and pupal durations were significantly prolonged under combined treatments (e.g. S. litura larval period: 17.81 days versus 16.13 days in control; pupal period: 11.62 versus 10.36 days). Nutritional indices declined markedly: efficiency of conversion of ingested food (ECI) in H. armigera decreased from 18.65% (control) to 15.31% (treated), and efficiency of conversion of digested food (ECD) in S. litura dropped from 18.14% to 14.02%. Relative consumption and growth rates also were reduced, indicating impaired feeding and growth performance. Calcium silicate application, particularly through combined foliar and soil treatments, negatively influenced larval development and food utilization in S. litura and H. armigera. These findings highlight silicon's potential as an ecofriendly component of integrated pest management strategies in groundnut cultivation, offering a sustainable alternative to synthetic insecticides. © 2026 Society of Chemical Industry.

FKBP12, the 12-kDa FK506-binding protein, plays a critical role in insect development and mammalian ABC transporter regulation. Our previous work showed that FK506 enhanced Cry1Ac toxicity in Helicoverpa armigera. We hypothesized that binding of FK506 to FKBP12 disrupted ABCC2 function, thereby influencing Cry1Ac toxicity. To test this, we examined FKBP12's effect on Cry1Ac toxicity and its interaction with ABCC2. We found that both FKBP12 and ABCC2 were downregulated in Cry1Ac-exposed and resistant H. armigera. Silencing HaFKBP12 significantly decreased the susceptibility of Helicoverpa zea midgut cells to Cry1Ac, whereas overexpressing it in Sf9 cells increased the susceptibility. FKBP12 directly binds ABCC2 and modulates its transport activity. Importantly, HaFKBP12 overexpression enhances the HzABCC2 sensitivity to Cry1Ac. These findings show that FKBP12 regulates ABCC2 to influence Cry1Ac toxicity, expanding our understanding of Bt toxin mechanisms. Moreover, the interaction between FKBP12 and ABCC2 offers insights into overcoming ABC transporter-mediated pesticide resistance and identifying new insecticidal targets.

Background: Green gram (Vigna radiata L.) is a vital pulse crop in Assam, but its productivity is constrained by insect pests such as whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae); the leaf roller Nacoleia vulgalis (Guenée)(Lepidoptera: Crambidae); the gram pod borer Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), spotted pod borer, Maruca vitrata (Fabricius) (Lepidoptera: Crambidae); the pod bug, Riptortus pedestris (Fabricius) (Hemiptera: Alydidae), Nezara viridula (Linnaeus) (Hemiptera: Pentatomidae) and the aphid Aphis craccivora Koch (Hemiptera: Aphididae). Farmers generally rely on indiscriminate pesticide use, leading to ecological and economic concerns. Bio-Intensive Pest Management (BIPM) offers an eco-friendly alternative by integrating botanicals, biopesticides and cultural practices. Methods: Field experiments were conducted during 2021-22 to 2023-24 at multiple locations across Assam to evaluate the efficacy of a BIPM module against major insect pests of green gram. The BIPM module comprised: (i) two rows of sesame as a barrier crop, (ii) timely weeding at 30 DAS, (iii) installation of yellow sticky traps (30 cm × 20 cm) @ 30/ha at 30 DAS and (iv) spray of Azadirachtin 300 ppm @ 5 ml/L at vegetative stage; compared with farmers’ practice (FP: Weeding + application of chlorantraniliprole 18.5 SC @ 0.3 ml/L). Pest incidence, pod damage, yield and benefit-cost ratio were recorded and statistically analyzed for different years at varied locations. Result: The BIPM module significantly reduced pest incidence compared to FP. Pooled mean whitefly and leaf roller incidence were 0.84/trifoliate leaf and 1.09%, respectively, under BIPM, against 3.39/trifoliate leaf and 4.48% under FP. Pod borer and pod bug damage were also lower (3.88% and 4.65%) in BIPM plots compared to FP (16.47% and 19.45%). Yield was consistently higher under BIPM (1028.07 kg/ha), representing a 13.39% increase over FP (906.63 kg/ha). Location-wise trials confirmed the superiority of BIPM, with yield advantages ranging from 6.49% to 34.84%. The benefit-cost ratio (1:2.06-1:2.52) was also higher in BIPM plots. Multi-location trials confirmed 6.49-34.84% yield advantage of BIPM across diverse agro-ecological zones of Assam. The findings suggest that the BIPM module provides a sustainable and eco-friendly alternative to pesticide-based practices for effective pest management in green gram, with positive implications for productivity and profitability.

The legume pod borer, Helicoverpa armigera (Hübner), is one of the pervasive and destructive pests of legume crops, causing significant yield losses. In this study, we evaluated the nutritional performance and digestive enzyme activities of H. armigera when fed on ten mung bean varieties, including Baghmalek, India, Veys, Omrani, Parto, Simite1, Simite2, VC6371, VC3960, and VC6368. Additionally, biochemical profiling of these mung bean varieties, assessing starch, protein, anthocyanin, total phenolic and flavonoid content, was conducted to explore potential correlations with the nutritional physiology of H. armigera. The findings indicated that the larvae fed on Parto had lowest approximate digestibility, efficiency of conversion of ingested food, and relative growth rate, while those fed on VC6371 had the highest values. The values of efficiency of conversion of digested food were lower on Baghmalek and Parto and higher on VC6368 and VC6371. The lowest value of larval gain weight was on Parto. The highest proteolytic and amylolytic activities of larvae were observed on Veys and India, respectively; while the lowest enzyme activities were recorded on Parto. Our findings indicate that the low protein content combined with high levels of anthocyanin, total phenolics, and flavonoids may contribute to the potential tolerance of mung bean varieties against H. armigera. Cluster analysis revealed that VC6368 and VC6371 were the most suitablevarieties for H. armigera development, whereas Baghmalek and Parto were nutritionally less suitableand may severe as promising candidates for breeding or cultivation to minimise damage caused by this pest.

Abstract Understanding the oviposition and foraging behaviour of pestiferous lepidopterans on their economically important food plants guides the development of effective pest management tactics. Here, we examined the oviposition behaviour and larval establishment of three noctuid species on a single crop—capsicum ( Capsicum annuum ). We selected pest species that are known to infest capsicum crops to varying degrees—the cotton bollworm, Helicoverpa armigera ; the cluster caterpillar, Spodoptera litura ; and the fall armyworm, Spodoptera frugiperda . Although related, these species differ in their known host‐plant preferences and larval feeding behaviour. We conducted a series of glasshouse experiments examining moth oviposition and larval survival on different crop stages and the ability of neonate larvae to feed and establish on capsicum fruits at different stages of development. Although all three species oviposited on capsicum plants, S. litura laid more eggs than the other species and targeted most of their eggs to plants rather than the cage wall, indicating a preference for the plant. S. litura larvae demonstrated the highest level of survival (48%) when left unrestricted on capsicum plants, whereas only a small proportion of S. frugiperda (12%) and H. armigera (3%) larvae survived on capsicum plants. Surprisingly, most surviving S. frugiperda larvae were found feeding inside capsicum fruits. The results generated in this study demonstrate how in‐field infestations of these noctuids in capsicum arise and will guide further development of pest management strategies for these pests in capsicum.

Embryonic transcription factors act as regulators of trehalose metabolism in Helicoverpa armigera

Efficient mate location is critical for reproductive success in male moth. While plant volatiles can synergize attraction to sex pheromones in many insects, the underlying mechanisms remain poorly understood. We examined this interaction using the cotton bollworm Helicoverpa armigera, a major pest that serves as a model due to its well-defined pheromone system. We found that the plant volatiles (Z)-3-hexenyl acetate and linalool were not attractive alone, yet each significantly enhanced male attraction when combined with the sex pheromone in wind tunnel assays. Single sensillum recording revealed that this synergy occurs peripherally within the pheromone-sensitive type A sensilla. Furthermore, transgenic Drosophila OR expression, and CRISPR-Cas9-mediated HarmPBP1 knockout, demonstrated that the pheromone-binding protein HarmPBP1, but not the odorant receptor HarmOR13, is critical for the synergistic effect of (Z)-3-hexenyl acetate. Our study elucidates a peripheral mechanism for olfactory signal integration, providing insights for developing sustainable behavioral control strategies.

Weather driven variation in the population dynamics of Helicoverpa armigera and avian predators in chickpea

Marigold (Tagetes sp.), a widely cultivated ornamental and medicinal plant, is economically significant in India. However, its productivity is compromised by infestations of key pests such as thrips (Thrips tabaci), mites (Tetranychusurticae), and bud borers (Helicoverpa armigera). Farmers often rely on excessive pesticide applications, leading to pest resistance, environmental pollution, and adverse effects on non-target organisms. This study underscores the importance of integrating organic amendments, botanicals, and selective pesticides in IPM modules to balance productivity and environmental health in marigold cultivation. Under the evaluation of the effectiveness of Integrated Pest Management (IPM) modules in controlling major pests in marigold crop reveals that four IPM modules were tested: Module-I (Bio-intensive), Module-II (Adaptable IPM), Module-III (Farmer practices), and Module-IV (Untreated check). Pest populations were recorded at fortnightly intervals, and flower damage and yield were assessed. Results showed that Module-IIincorporated cultural practices, organic amendments, and selective chemical controls, including neem cake, vermicompost, border crops, and advanced pesticides, consistently recorded the lowest pest populations and flower damage. Thrips and mite populations averaged 4.14 per plant and 0.24 per leaf, respectively, while bud borer larvae averaged 0.31 per plant. Flower damage was significantly reduced to 3.01%, and the yield was the highest at 10.52 tons/ha. While, Module-III (Farmer practices) relied heavily on chemical applications, achieving moderate pest control with 4.66 thrips per plant, 0.27 mites per leaf, and 0.51 larvae per plant. Module-I showed lower pest control efficacy due to the exclusive use of bio-intensive measures, while Module-IV exhibited the highest pest populations and flower damage, resulting in the lowest yield (5.40 tons/ha). This study underscores the importance of integrating organic amendments, botanicals, and selective pesticides in IPM modules to balance productivity and environmental health in marigold cultivation.

Helicoverpa armigera is a typical polyphagous species whose larvae primarily bore in flower buds and fruits of host plants, causing serious damage to many crops. Olfaction plays a key role in host selection, but the molecular basis of olfactory perception in larvae is poorly understood. Herein, we identified a highly expressed odorant receptor, HarmOr54, in larval antennae through qRT-PCR and in situ hybridization experiments. Drosophila T1 neurons expressing HarmOr54 ectopically showed specific responses to (-)-bornyl acetate and 2-ethylhexyl acetate. CRISPR/Cas9-generated homozygous mutant larvae lost avoidance to (-)-bornyl acetate, unlike wild-type larvae, while 2-ethylhexyl acetate showed no behavioral effect. Structural modeling and docking revealed that both ligands bound to the same HarmOr54 pocket, but (-)-bornyl acetate displayed stronger binding affinity. These findings enhance our understanding of the olfactory mechanisms in lepidopteran larvae and provide new insights into pest control strategies targeting the larval stage.

Gut microbes modulate Helicoverpa armigera immunity and affect its susceptibility to microbial pathogens.

Baculoviruses are large DNA viruses that mainly infect insects. During infection, viral egress from midgut cells and subsequent behavior changes lead to terminally infected insects migrating to higher elevations on plant branches or tree limbs. However, the neural mechanisms driving this hyperactivity remain poorly understood. In this study, we demonstrate that the climbing behavior of Helicoverpa armigera larvae enhances the dispersal of Helicoverpa armigera single nucleopolyhedrovirus (HearNPV). Our findings reveal that HearNPV triggers a calcium response in enteroendocrine cells, leading to the release of midgut-derived tachykinin (TK). Released TK activates its receptor (TKR) in the brain, thereby promoting phototaxis and climbing behavior. Additionally, HaTTD14 functions as a downstream regulator of the TK-TKR signaling pathway. These results provide insights into the neural and molecular mechanisms driving baculovirus-induced hyperactivity, which aids in viral transmission.

Phyllosphere microorganisms play a vital role in plant defense, thereby aiding plants in their adaptation to environmental changes. Plant hormone signals can regulate the composition of the phyllosphere microbial community. Jasmonic acid (JA) is a critical phytohormone that regulates anti-herbivore pathways in plants; however, the dialogue between JA and phyllosphere microorganisms in anti-herbivore defense remains unclear. Here, we investigate the role of JA-enriched phyllosphere microorganisms in the defense of tomato plants against Helicoverpa armigera Hübner. Our results demonstrate that JA-enriched phyllosphere bacteria enhance the direct defense of tomato plants by inhibiting the development of H. armigera larvae. Furthermore, these microorganisms increase the plants' ability to attract predatory Harmonia axyridis Pallas by elevating the emission of specific volatile organic compounds (VOCs) namely α-pinene, α-terpinene, and caryophyllene. We observed positive correlations between the abundance of phyllosphere microorganisms, the level of VOC emissions, and the density of trichomes, suggesting an integrated anti-herbivore defense network regulated by JA. These findings underscore the importance of phyllosphere microorganisms in enhancing plant fitness and further comprehension of the intricate relationship between plant anti-herbivore defenses and phyllosphere microorganisms. © 2026 Society of Chemical Industry.

Matrix metalloproteinases (MMPs) play crucial roles in both physiological and pathological conditions by degrading the extracellular matrix; however, the roles and regulatory mechanisms of MMPs in brain development remain insufficiently understood. In this study, using the lepidopteran insect Helicoverpa armigera, the cotton bollworm, a serious agricultural pest, as an experimental model, we revealed that MMP2 is an important factor in insect brain development during metamorphosis under steroid hormone 20-hydroxyecdysone (20E) regulation. MMP2 is highly expressed in the brain during metamorphosis. MMP2 is localized in some surface and internal cells in the brain during metamorphosis. The knockdown of Mmp2 by RNA interference in larvae repressed brain development, accompanied by an increase in autophagy and a decrease in cell proliferation. In addition, the nutrient levels of glucose and glutamate decreased in the brain, and the expression of glucose transporters and glutamate transporters decreased after Mmp2 was knocked down. The transcription of Mmp2 was upregulated by 20E via the transcription factor forkhead box O (FOXO) in a time- and concentration-dependent manner. These data suggest that MMP2 facilitates neural cell proliferation and nutrient supply, and ultimately regulates brain development during insect metamorphosis.

Tomato (Solanum lycopersicum L.) is vital for global nutrition and economic stability, yet it is threatened by pests such as Tuta absoluta, Helicoverpa armigera, and Bemisia tabaci. Effective pest management is crucial to prevent significant crop losses. Traditional pest detection methods relying on human observation are labor-intensive, time consuming, and prone to errors. In contrast, artificial intelligence (AI)based models such as YOLO provide timely and accurate pest identification, enhancing pest management practices. In this study, images captured throughout the tomato plant’s development, from seedling to fruit stage, were used for model training. The capabilities of the YOLOv8 model in detecting and segmenting tomato pests were evaluated. The results demonstrated significant improvements in both detection and segmentation tasks, with precision and recall reaching 98.91% and 98.98% for detection, and 97.47% and 98.81% for segmentation, respectively. These findings underscore the accuracy and robustness of the YOLOv8 model in monitoring diverse pest species, highlighting its potential to improve agricultural pest management practices. Although YOLO-based detectors have recently been tested on a limited set of pest species, comprehensive field-scale evaluations remain scarce. By assessing YOLOv8 across eleven pest taxa under commercial field conditions, this study delivers among the more comprehensive practice-oriented benchmarks to date for multi-species pest monitoring. This research suggests that integrating AI models like YOLOv8 into pest monitoring systems can contribute to more efficient and sustainable agricultural practices by minimizing human error and labor demands. Furthermore, future applications could extend this approach to other crops and pest species, validating the model’s versatility and supporting long-term farming sustainability.

Disruption of reproduction is an important pest control tactics for management of high-fecundity pests like Helicoverpa armigera (Hübner). In this study, we investigated the role of the testis-biased miR-252a-5p in regulating gonad development and reproduction. Through a combination of bioinformatics prediction, dual luciferase reporter assays, functional injections (agomir, antagomir, and siRNA), and phenotypic evaluations, we identified OVOL as a key target gene of miR-252a-5p. We found that miR-252a-5p negatively regulates OVOL expression. Injection of miR-252a-5p agomir or OVOL siRNA into newly emerged females delayed egg maturation and reduced hatching rates. In contrast, inhibiting miR-252a-5p or knocking down OVOL in larval stages did not affect testis development or fertility. These results demonstrate that miR-252a-5p specifically targets OVOL to modulate ovarian development and reproductive success in H. armigera. Both miR-252a-5p and OVOL represent promising targets for reproduction-based control of this and other lepidopteran pests.