The Asian corn borer (ACB), Ostrinia furnacalis (Guenée, 1854), is a serious pest of several crops, particularly a destructive pest of maize and other cereals throughout most of Asia, including China, the Philippines, Indonesia, Malaysia, Thailand, Sri Lanka, India, Bangladesh, Japan, Korea, Vietnam, Laos, Myanmar, Afghanistan, Pakistan and Cambodia. It has long been known as a pest in South-east Asia and has invaded other parts of Asia, Solomon Islands, parts of Africa and certain regions of Australia and Russia. Consequently, worldwide efforts have been increased to ensure new control strategies for O. furnacalis management. In this article, we provide a comprehensive review of the ACB covering its (i) distribution (geographic range and seasonal variations), (ii) morphology and ecology (taxonomy, life-history, host plants and economic importance) and (iii) management strategies (which include agroecological approaches, mating disruption, integrated genetic approaches, chemical as well as biological control). Furthermore, we conclude this review with recommendations to provide some suggestions for improving eco-friendly pest management strategies to enhance the sustainable management of ACB in infested areas.
Insecticides play a crucial role as the primary means of controlling agricultural pests, preventing significant damage to crops. However, the misuse of these insecticides has led to the development of resistance in insect pests against major classes of these chemicals. The emergence of resistance poses a serious threat, especially when alternative options for crop protection are limited for farmers. Addressing this challenge and developing new, effective, and sustainable pest management approaches is not merely essential but also critically important. In the absence of alternative solutions, understanding the root causes behind the development of resistance in insects becomes a critical necessity. Without this understanding, the formulation of effective approaches to combat resistance remains elusive. With insecticides playing a vital role in global food security and public health, understanding and mitigating resistance are paramount. Given the growing concern over insect resistance to insecticides, this review addresses a crucial research gap by thoroughly examining the causes, mechanisms, and potential solutions. The review examines factors driving resistance, such as evolutionary pressure and excessive pesticide use, and provides a detailed analysis of mechanisms, including detoxifying enzyme overproduction and target site mutations. Providing an analysis of potential solutions, it discusses integrated pest management, strategic insecticide rotation, and the use of new pest control technologies and biological agents. Emphasizing the urgency of a multifaceted approach, the review provides a concise roadmap for sustainable pest management, guiding future research and applications.
Companion planting, the practice of growing different plant species together, can be a sustainable pest management strategy. However, the specific role of garlic as a companion plant for Brassica in aphid suppression, particularly against Myzus persicae (Sulzer) (Hemiptera: Aphididae), is not well understood. This study investigated the potential of planting garlic (Allium sativum L., Asparagales: Amaryllidaceae) with Brassica rapa L. (Brassicales: Brassicaceae) to reduce M. persicae infestations and explores its impact on the biocontrol agent Harmonia axyridis Pallas (Coleoptera: Coccinellidae). We hypothesized that the combination of A. sativum and B. rapa would synergistically reduce aphid infestations compared to Brassica monocultures. To test this, M. persicae performance was evaluated on Brassica plants under three conditions: a single Brassica plant (B), two Brassica plants (BB), and a Brassica plant with garlic (BG). Parameters such as aphid survival, fecundity, developmental time, and population increase were measured. Additionally, Y-olfactometer bioassays assessed the behavioral responses of M. persicae and H. axyridis. The results showed that the BG combination significantly reduced aphid survival, fecundity, and population growth while delaying developmental time compared to B and BB. M. persicae preferred volatiles from B and BB plants, while H. axyridis was more attracted to BG volatiles, indicating garlic's potential to enhance biocontrol agent recruitment. This study highlights the potential of garlic as a companion plant to improve Brassica crop protection against M. persicae and enhance the effectiveness of biocontrol agents.
The adaptability of agricultural pests to varied environments is a critical factor in their ability to cause significant damage, making it a major challenge for effective crop management. While the adaptability of Asian corn borer (Ostrinia furnacalis) (Lepidoptera: Crambidae) is well-documented, the extent to which different populations diverge in fitness when reared on natural versus artificial diets remains poorly understood. This study addresses this gap by assessing the fitness and adaptive divergence of three O. furnacalis populations i.e., field, laboratory, and hybrid (field x laboratory), when reared on maize and artificial diets, using age-stage, two-sex life table theory. Significant differences in survival and demographic parameters were observed among the populations. The field population exhibited 32.5 % faster growth on maize, with a shorter mean generation time (T) compared to the artificial diet. In contrast, the laboratory population grew (T) 29.5 % faster on the artificial diet compared to maize. The hybrid population showed a slight preference for maize, with growth (T) being 3.1 % faster than on the artificial diet. Trends in intrinsic rate of increase (r), finite rate of increase (lambda) and other associated parameters followed a consistent pattern, with field population thriving on maize and laboratory population better suited to the artificial diet. The hybrid population demonstrated balanced adaptability to both diets, with an overall slight tendency of better performing on maize. This study highlights the importance of diet-specific adaptation in O. furnacalis and provides critical insights into the adaptive divergence for optimising laboratory rearing practices and improving pest management strategies.
The Asian corn borer, Ostrinia furnacalis (Guenée), emerges as a significant threat to maize cultivation, inflicting substantial damage upon the crops. Particularly, its larval stage represents a critical point characterised by significant economic consequences on maize yield. To manage the infestation of this pest effectively, timely and precise identification of its larval stages is required. Currently, the absence of techniques capable of addressing this urgent need poses a formidable challenge to agricultural practitioners. To mitigate this issue, the current study aims to establish models conducive to the identification of larval stages. Furthermore, this study aims to devise predictive models for estimating larval weights, thereby enhancing the precision and efficacy of pest management strategies. For this, 9 classification and 11 regression models were established using four feature datasets based on the following features geometry, colour, and texture. Effectiveness of the models was determined by comparing metrics such as accuracy, precision, recall, F1-score, coefficient of determination, root mean squared error, mean absolute error, and mean absolute percentage error. Furthermore, Shapley Additive exPlanations analysis was employed to analyse the importance of features. Our results revealed that for instar identification, the DecisionTreeClassifier model exhibited the best performance with an accuracy of 84%. For larval weight, the SupportVectorRegressor model performed best with R2 of 0.9742. Overall, these findings present a novel and accurate approach to identify instar and predict the weight of O. furnacalis larvae, offering valuable insights for the implementation of management strategies against this key pest.
Behavioral studies play a crucial role in assessing food utilization in insects. However, there exists a gap in our understanding of the phenotypic plasticity in Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) and how it impacts their growth, development, and potential for plant damage. This study aimed to investigate the phenotypic plasticity of S. litura, with a focus on its immature stages, and evaluate the consequences of plant damage and pest management. We conducted in vitro experiments using both a standard artificial diet and tobacco (Nicotiana tabacum L., Solanaceae) plants to assess the growth, development, survival, longevity, reproductive capacity, and egg-laying capability of S. litura larvae and adults. A type II functional response was estimated for all larval instars, utilizing the Likelihood Holling's Disk model, which provided two key coefficients: the search rate (a) and handling time (Th). Our findings revealed that sixth instars exhibited exceptional agility and efficiency, requiring the shortest time to process each milligram of diet compared with other larval stages. Moreover, when larvae were fed on tobacco, they displayed the shortest developmental time and the highest fecundity. This trend extended to pupal weight, pupal duration, pupal emergence, fecundity, and longevity, which were all significantly higher in individuals fed on tobacco. Additionally, S. litura larvae that fed on tobacco exhibited greater efficiency in converting digested food and lower approximate digestibility compared to larvae fed the artificial diet. These results underscore the importance of focusing on the management of fourth, fifth, and sixth instars, which have the potential to cause severe plant damage. Understanding the functional and nutritional response of S. litura larvae enhances the efficiency of integrated pest management strategies (IPM) at early stages while minimizing ecological impact.
BACKGROUND: Egg parasitoids are important biological control agents of lepidopteran pests of agricultural crops. Trichogramma evanescens Westwood and T. pintoi Voegele (Hymenoptera: Trichogrammatidae) are egg parasitoids with worldwide importance. The parasitoid selection necessitates comparative assessment of the life table traits and functional response analysis to provide insights into their effectiveness in pest control. In this study, we examined their life table traits including survivorship and reproductivity, and functional response and associated parameters i.e., attack coefficient and handling time. RESULTS: Life table parameters, using age-stage, two-sex theory, revealed similar survival and reproductive strategies for both species. For example, the female longevity, oviposition days and fecundity did not differ between both species. Exceptionally, the male longevity of T. evanescens was shorter than that of T. pintoi. The population growth parameters such as gross reproductive rate (GRR), net reproductive rate (R-0), intrinsic rate of increase (r), finite rate of increase (lambda), and mean generation time (T) did not differ between species. The polynomial logistic regression yielded a type III functional response and a non-linear least square analysis revealed different attack coefficient and similar handling time. However, their parasitism rate differed between the lowest (five eggs) and highest (80 eggs) initial host egg densities such that T. evanescens had a lower parasitism rate at the lowest density and higher parasitism rate at the highest density. CONCLUSION: The similarity in survival strategies and minor differences in host handling of both parasitoids are discussed in terms of relevance to applied biological control applications and evolutionary traits. (c) 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Lateralisation is a well-established phenomenon observed in an increasing number of insect species. This study aims to obtain basic details on lateralisation in courtship and mating behaviour in Ostrinia furnacalis, the Asian corn borer. We conducted laboratory investigations to observe lateralisation in courtship and mating behaviours in adult O. furnacalis. Our goal was also to detect lateralised mating behaviour variations during sexual interactions and to elucidate how these variances might influence the mating success of males. Our findings reveal two distinct lateralised traits: male approaches from the right or left side of the female and the direction of male turning displays. Specifically, males approaching females from their right side predominantly exhibited left-biased 180(degrees) turning displays, while males approaching females from the left-side primarily displayed right-biased 180(degrees) turning displays. Notably, left-biased males, executing a 180(degrees) turn for end-to-end genital contact, initiated copulation with fewer attempts and began copulation earlier than their right-biased approaches with left-biased 180(degrees) turning displays. Furthermore, mating success was higher when males subsequently approached the right side of females during sexual encounters. Left-biased 180(degrees) turning males exhibited a higher number of successful mating interactions. These observations provide the first report on lateralisation in the reproductive behaviour of O. furnacalis under controlled laboratory conditions and hold promise for establishing reliable benchmarks for assessing and monitoring the quality of mass-produced individuals in pest control efforts.
The greater wax moth, Galleria mellonella L., poses a substantial threat to apiculture, adversely impacting wax quality and potentially acting as a disease vector. There is an urgent need to develop innovative and effective control strategies to address the challenges posed by this pest and ensure the sustainability of the apiculture industry. Spiro-derivative compounds represent a novel class of environmentally safe compounds with high insecticidal properties. For example, they have demonstrated high efficacy against sap-sucking insects such as aphids and whiteflies. However, their effect on chewing insects has not yet been well explored. In this study, we hypothesized that 4-amino-1-azaspiro[4.5]dec-3-en-2-one (4A1AD), a spiro-derivative compound, would exhibit efficacy against G. mellonella larvae. To test this hypothesis, we conducted dipping and feeding bioassays, incorporating varying concentrations of 4A1AD on fourth instar G. mellonella larvae, and recorded mortality, biochemical parameters including total soluble protein content and enzyme activities, and anatomical abnormalities resulting from treatment. Results revealed a significant increase in larval mortality with increased concentrations and treatment durations across both bioassays. Additionally, a significant decrease in protein content and an increase in phenol-oxidase activity were observed with alterations in alpha and beta-esterase activities. Scanning electron microscope findings revealed abnormalities in larval cuticle, spiracular openings and legs. These findings demonstrated the efficacy of 4A1AD, indicating a potential alternative to conventional insecticides in promoting sustainable apiculture practices. Moreover, they provide valuable contributions to the development of novel strategies for effective pest management in apicultural settings.
Phytohormones, pivotal regulators of plant growth and development, are increasingly recognized for their multifaceted roles in enhancing crop resilience against environmental stresses. In this review, we provide a comprehensive synthesis of current research on utilizing phytohormones to enhance crop productivity and fortify their defence mechanisms. Initially, we introduce the significance of phytohormones in orchestrating plant growth, followed by their potential utilization in bolstering crop defences against diverse environmental stressors. Our focus then shifts to an in-depth exploration of phytohormones and their pivotal roles in mediating plant defence responses against biotic stressors, particularly insect pests. Furthermore, we highlight the potential impact of phytohormones on agricultural production while underscoring the existing research gaps and limitations hindering their widespread implementation in agricultural practices. Despite the accumulating body of research in this field, the integration of phytohormones into agriculture remains limited. To address this discrepancy, we propose a comprehensive framework for investigating the intricate interplay between phytohormones and sustainable agriculture. This framework advocates for the adoption of novel technologies and methodologies to facilitate the effective deployment of phytohormones in agricultural settings and also emphasizes the need to address existing research limitations through rigorous field studies. By outlining a roadmap for advancing the utilization of phytohormones in agriculture, this review aims to catalyse transformative changes in agricultural practices, fostering sustainability and resilience in agricultural settings.
The maize crop is highly susceptible to damage caused by its primary pests, which poses considerable challenges in manually identifying and controlling them at various larval developmental stages. To mitigate this issue, we propose an automated classification system aimed at identifying the different larval developmental stages of 23 instars of 4 major lepidopteran pests: the Asian corn borer, Ostrinia furnacalis (Guen & eacute;e; Lepidoptera: Crambidae), the fall armyworm, Spodoptera frugiperda (J.E. Smith; Lepidoptera: Noctuidae), the oriental armyworm, Mythimna separata (Walker; Lepidoptera: Noctuidae), and the tobacco cutworm, Spodoptera litura (Fabricius; Lepidoptera: Noctuidae). Employing 5 distinct Convolutional Neural Network architectures-Convnext, Densenet121, Efficientnetv2, Mobilenet, and Resnet-we aimed to automate the process of identifying these larval developmental stages. Each model underwent fine-tuning using 2 different optimizers: stochastic gradient descent with momentum and adaptive moment estimation (Adam). Among the array of models tested, Densenet121, coupled with the Adam optimizer, exhibited the highest classification accuracy, achieving an impressive 96.65%. The configuration performed well in identifying the larval development stages of all 4 pests, with precision, recall, and F1 score evaluation indicators reaching 98.71%, 98.66%, and 98.66%, respectively. Notably, the model was ultimately tested in a natural field environment, demonstrating that Adam_Densenet121 model achieved an accuracy of 90% in identifying the 23 instars of the 4 pests. The application of transfer learning methodology showcased its effectiveness in automating the identification of larval developmental stages, underscoring promising implications for precision-integrated pest management strategies in agriculture.
Plants exhibit a remarkable capacity to discern between self-inflicted damage, herbivore attacks, and mechanical harm through pattern recognition, detecting specific signals associated with each type of damage. Mechanical damage significantly influences plant defence responses against herbivorous insects. This study aimed to artificially activate the plant defence system and observe the performance of aphid (Myzus persicae Sulzer) (Hemiptera: Aphididae) and their parasitoid (Diaeretiella rapae M’Intosh) (Hymenoptera: Braconidae) on brassica plants. Mechanically damaged and undamaged plants were subjected to aphid infestation, and various parameters related to aphid and parasitoid performance, including adult survival, fecundity, aphid settlement, and oviposition behavior, were measured. Results revealed that plants with artificial damage exhibited greater resistance to aphids than undamaged plants. In the cage bioassay, there was a notable 17
BACKGROUNDAcrylamide-based bait has super water absorption making it highly attractive to subterranean termites that are lured by wood with high water content. This study investigated the control efficiency of these baits on subterranean termites. In particular, we evaluated the water-absorption capacity, attractiveness to subterranean termites, and control efficiency of these baits on subterranean termites through wooden blocks (Populus deltoides and three types of particleboards).RESULTSThe results indicated a substantial water absorption capacity of acrylamide (70.6%; control: 14.8%) and a strong attraction for feeding subterranean termites (P. deltoides: 198 highest; 81 lowest subterranean termites individuals; combination of neem leaves and walnut shells: 168 highest; 36 lowest subterranean termites individuals). When acrylamide was combined with boric acid at the highest concentration, it resulted in the lowest wood consumption rates (P. deltoides: 24.1%; control: 63.8%, combination of neem leaves and walnut shells: 32.5%; control: 62.1%).CONCLUSIONSIn conclusion, this research supports the commercial viability of employing innovative acrylamide-based toxic baits and particleboards for subterranean termite management. (c) 2024 Society of Chemical Industry. Conventional termite control methods fall short, while our study highlights the success of novel acrylamide-based baits in termite attraction and control. When used in tandem with innovative particleboard blocks, a potent termite-resistant solution emerges. Our eco-friendly approach signals a game-changer in termite management, ushering in a sustainable pest control era. image
Plants have evolved distinct defense strategies in response to a diverse range of chewing and sucking insect herbivory. While chewing insect herbivores, exemplified by caterpillars and beetles, cause visible tissue damage and induce jasmonic acid (JA)-mediated defense responses, sucking insects, such as aphids and whiteflies, delicately tap into the phloem sap and elicit salicylic acid (SA)-mediated defense responses. This review aims to highlight the specificity of defense strategies in Brassica plants and associated underlying molecular mechanisms when challenged by herbivorous insects from different feeding guilds (i.e., chewing and sucking insects). To establish such an understanding in Brassica plants, the typical defense responses were categorized into physical, chemical, and metabolic adjustments. Further, the impact of contrasting feeding patterns on Brassica is discussed in context to unique biochemical and molecular modus operandi that governs the resistance against chewing and sucking insect pests. Grasping these interactions is crucial to developing innovative and targeted pest management approaches to ensure ecosystem sustainability and Brassica productivity.
Honeydew, a sugary excretion produced by sap-feeding insects, plays a pivotal role in shaping intricate interactions between insects and plants. This review explains the multifaceted aspects of honeydew, beginning with an overview of its production mechanisms and factors influencing its variability across insect species and plant hosts. Exploring its composition, we examine the chemical components and nutritional aspects, highlighting variations based on insect species and plant sources. The impact of honeydew on microbial communities is explored, shedding light on its role in influencing the diversity and abundance of microorganisms. Furthermore, the review investigates how honeydew affects pest behaviour and population dynamics, elucidating plant responses to honeydew deposition. In the realm of biocontrol, we examine the intricate relationships between honeydew and natural enemies, considering potential implications for integrated pest management. Beyond these individual components, the paper discusses the broader ecological consequences of honeydew in ecosystems, emphasizing the interconnected relationships between insects, plants and microorganisms. The review concludes by identifying research gaps and suggesting future directions, recognizing the need for further investigation into areas with potential applications for agriculture and ecology. This review provides a comprehensive synthesis of the current understanding of honeydew's significance in insect-plant interactions, offering insights for both researchers and practitioners in the field.
Insect–plant interactions within ecological systems have captivated scientists for over several years, particularly focusing on agricultural pests and their extensive impact on plant health. Despite the article emphasis on feeding patterns, it is essential to highlight the significance of feeding patterns and types of mouthparts in insect herbivores, which are pivotal in understanding insect–plant interactions within ecological systems. In response to insect attacks, plants undergo dynamic biochemical alterations, resulting in the stimulated synthesis of both direct and indirect defense mechanisms. We elucidated the crucial need to understand insect feeding patterns and their diverse feeding mechanisms and navigated through the intricacies of chewing and piercing–sucking herbivores, shedding light on their diverse feeding mechanisms and behavioral adaptations while invading new hosts. This review reveals the direct correlation between insect feeding patterns and the resultant plant damage. From biochemical alterations in plants to the activation of defense mechanisms, including the jasmonic acid and salicylic acid pathways, Ca2+ flux, reactive oxygen species (ROS) burst, mitogen-activated protein kinase (MAPK) activation, and other responses, are triggered when insect exposure was detected on different plants. Furthermore, the review unravels the ecological implications of these interactions, emphasizing the significance of comprehending these interactions in devising effective pest management strategies. Conclusively, this review aims to underscore the importance of understanding insect feeding patterns and their associated elicitors and effectors.