Entomopathogenic Nematodes Research Articles

Effect of the Biostimulants of Microbiological Origin on the Entomopathogenic and Plant Parasitic Nematodes from Miscanthus × Giganteus Plantations

Abstract This study aimed to evaluate the effect of biostimulants derived from Streptomyces avermitilis metabolites on entomopathogenic nematodes: Steinernema carpocapsae, Steinernema feltiae, and Heterorhabditis bacteriophora, obtained from the soil of several Miscanthus × giganteus plantations in 2020–2023. The nematodes were isolated, identified, and cultured using live insects (the greater wax moth Galleria mellonella). Three preparations containing biostimulants – Charkor, Stimpo, and Regoplant, were tested for compatibility with entomopathogenic and plant parasitic nematodes. Their effect on nematode survival was evaluated using the Petri dish test. The study showed that the effect of biostimulants on the survival of nematodes depended on the concentration of aversectin contained in the evaluated preparations. Stimpo and Regoplant had an adverse effect on plant parasitic nematodes. The highest G. mellonella mortality was observed at the higher dose of Charkor (0.4%), and the lowest at the lower dose of Regoplant (1.22%). The study showed that the virulence of the nematodes decreased after 48 hours of incubation in Regoplant and Stimpo solutions containing aversectin. The degree of interaction between nematodes depended on the nematode species, trophic preferences, and the concentration of active ingredients in the preparations. This conclusion is crucial for the selection of appropriate types of entomopathogenic nematodes and the application rate of plant parasitic nematodes in the assessment of their short- and long-term spread, persistence, and recycling in field conditions.

Integrated approaches for Solenopsis invicta (Hymenoptera: Formicidae) management: insights from laboratory studies with entomopathogenic nematodes and insecticides.

In agricultural pest management, especially in combatting the invasive red imported fire ant (RIFA, Solenopsis invicta), significant challenges emerge as a consequence of the constraints of solely depending on chemical insecticides or entomopathogenic nematodes (EPNs). The utilization of chemical insecticides carries environmental and ecological hazards, whereas EPNs, when applied independently, might not offer the immediate effectiveness necessary for adequate RIFA suppression. Acknowledging these hurdles, our study investigates a synergistic method that integrates EPNs with chemical insecticides, aiming to fulfill the urgent demand for more efficient and environmentally friendly pest control solutions. Our evaluation focused on the interaction between the highly pathogenic Steinernema riobrave 7-12 EPN strain and prevalent insecticides, specifically beta-cypermethrin and a mixture of bifenthrin and clothianidin, applied at highly diluted recommended concentrations. The findings revealed a notable increase in RIFA mortality rates when EPNs and these insecticides were used together, outperforming the results achieved with each method individually. Remarkably, this enhanced efficacy was especially evident at lower concentrations of the bifenthrin-clothianidin mixture, indicating a valuable approach to minimizing reliance on chemical insecticides in agriculture. Furthermore, the high survival rates of EPNs alongside the tested insecticides indicate their compatibility and potential for sustained use in integrated pest management programs. Our research underscores the effectiveness of merging EPNs with chemical insecticides as a powerful and sustainable strategy for RIFA management. This combined approach not only meets the immediate challenges of pest control in agricultural settings, but also supports wider environmental objectives by reducing the dependency on chemical insecticides. © 2024 Society of Chemical Industry.

Characterisation and toxins analysis of symbiotic bacteria Photorhabdus luminescens isolated from Heterorhabditis indica ICRI-18 strain

Entomopathogenic nematodes are proven alternatives to pesticides in crop protection as they belong to the Heterorhabditidae and Steinernematidae families. The role of entomopathogenic nematodes has expanded considerably in the recent past for their efficacy as biopesticide which is influenced by nematode species and strain. Members of the genus Heterorhabditis have been found to harbor a symbiotic bacteria Photorhabdus sp. When the nematode is ingested by the insect, Photorhabdus sp. is released into the host haemocoel where they multiply rapidly and kill the insect. The main objective of our research was to examine the insect killing toxin property of symbiotic bacteria isolated from the entomopathogenic nematodes Heterorhabditis indica. The antagonistic potential of insecticidal toxin from Photorhabdus sp. was investigated. The results prove that toxic components produced by these bacteria could kill pests either through ingestion or injection. The broad-spectrum antimicrobial property produced by Photorhabdus sp. was analysed by conducting both antibiogram and antibiosis studies.

Pathogenicity of the Steinernema feltiae TUR-S3 (Rhabditida: Steinernematidae) Isolate on Oryzaephilus surinamensis (Coleoptera: Silvanidae) and Tribolium confusum (Coleoptera: Tenebrionidae)

For many years, pesticides have been employed to manage pests that cause losses in agricultural yield and quality during storage. However, as the harmful effects of pesticides on non-target organisms became apparent, alternative approaches gained traction. Entomopathogenic Nematodes (EPNs), commonly used in biological control, are now being considered for controlling Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) and Tribolium confusum du Val (Coleoptera: Tenebrionidae). This study evaluated the efficacy of Steinernema feltiae TUR-S3 (Rhabditida: Steinernema) isolate at five different concentrations (3 Infective Juveniles (IJs)/cm2 (8 IJs/adult), 6 IJs/cm2 (17 IJs/adult), 9 IJs/cm2 (25 IJs/adult), 18 IJs/cm2 (50 IJs/adult), 27 IJs/cm2 (75 IJs/adult)) against adult O. surinamensis and T. confusum. The results indicated the highest mortality rate, reaching 83.33%, was achieved in both pests at a concentration of 27 IJs/cm2 (75 IJs/adult). This suggests promising potential for controlling O. surinamensis and T. confusum using this approach.

The cryptic microbiota of plant parasitic and entomopathogenic nematodes: diversity, effects on host biology and potential in plant protection

AbstractMany plant parasitic and entomopathogenic nematodes harbor specialized and obligate bacteria as well as viruses. Given their evolutionary persistence, such cryptic species are considered to play effective roles during their host/microbe interactions lifetime, including mutualistic, antagonistic, or yet unknown host effects. To exploit such associations in plant protection, a comprehensive view is needed linking basic evolutionary relationships to applied aspects. This requires identifying the benefit or impact that hosts, acting as pests or biocontrol agents, receive from their endosymbionts. Targeting endosymbionts that are vital for a beneficial nematode or a pest may open novel perspectives for the management of their performance and traits, such as virulence or response to plant defense reactions. Some hypotheses are proposed to develop advanced control strategies through emerging biotechnological approaches.

Assessment of combined effects of some common agrochemicals and different entomopathogenic nematode species on the control of Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae) under controlled conditions

Assessment of combined effects of some common agrochemicals and different entomopathogenic nematode species on the control of Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae) under controlled conditions

Laboratory Evaluation of Indigenous and Commercial Entomopathogenic Nematodes against Red Palm Weevil, Rhynchophorus ferrugineus (Coleoptera: Curculionidae).

The red palm weevil (RPW) is a significant threat to date palms. Conventional pest control has been ineffective. This study aims to evaluate entomopathogenic nematodes (EPNs) indigenous to Saudi Arabia and commercial against RPW. We used 33 soil samples collected from four areas of Saudi Arabia. The indigenous EPNs were isolated and cultured using an insect baiting method to obtain infective juveniles. Pathogenicity bioassays were conducted against different stages of RPW, including eggs, larvae, and adults. The bioassay was performed using all the isolates at 1 × 106 IJ/mL. Distilled water was used as a control. The results revealed that only 9.09% of soil samples contained positive EPNs. Through DNA sequencing analysis, the positive samples were identified as indigenous isolates belonging to Heterorhabditis indica and Steinernema carpocapsae EPN species. In pathogenicity tests, 90% mortality of RPW eggs was observed after five days. Similar mortality trends were seen in RPW larvae and adults, with 90% mortality recorded after ten days for all the EPN treatments. Mortality increased with the duration of post-EPN inoculation exposure. The 1 × 106 IJ/mL concentrations of EPN effectively killed various stages of RPW in the laboratory. More research is needed to test EPNs against RPW in the field.

Identification and biocontrol potential of entomopathogenic nematodes, Steinernema siamkayai occurring in western Thailand against the common cutworm, Spodoptera litura Fabricius (Lepidoptera: Noctuidae) under laboratory and screenhouse conditions

AbstractThe common cutworm, Spodoptera litura, is a serious insect pest of many vegetables and crops worldwide. Entomopathogenic nematodes (EPN) have been utilized as biological control agents for controlling various insect pests, including the larvae of S. litura. Many indigenous EPN have been recognized to be more effective in specific field applications. Among the 160 soil samples collected in undisturbed areas of western Thailand, three samples tested positive for EPN. Three indigenous EPN were identified as Steinernema siamkayai namely, EPNKU63, EPNKU70 and EPNKU85, based on ITS and D2/D3 expansion region analysis of the 28s rRNA genes. Additionally, genetic analysis of the symbiotic bacteria using recA rRNA sequences confirmed their identity as Xenorhabdus stockiae namely, PEPNKU63, PEPNKU70 and PEPNKU85. To evaluate their initial biocontrol potential against the 6th instar larvae of Galleria mellonella, virulence assays were conducted. The application of 100 infective juveniles (IJs)/insects resulted in the mortality of 80–100% of G. mellonella larvae after 72 h. When symbiotic bacteria were applied at 1 × 106 cells/insect, they exhibited 63–93% mortality against G. mellonella larvae after 120 h. In further laboratory tests, three S. siamkayai isolates achieved 100% mortality of 3rd instar Spodoptera litura larvae within 72 h, with LC50 values ranging from 29 to 30 IJs/insect. In screenhouse experiments, it was revealed that all S. siamkayai isolates displayed substantial virulence, ranging from 62% to 74%, against 3rd instar S. litura larvae within 72 h. This study demonstrates the biocontrol potential of S. siamkayai in controlling S. litura larvae.

Anti-aging effect of glycerophosphocholine in Steinernema kraussei 0657L.

Glycerophosphocholine (GPC) is a water-soluble small molecule found naturally in humans and foods such as milk and soybeans. It can activate the IIS pathway by regulating the expression of daf-2, ins-18 and daf-16 genes, sek-1 and skn-1 genes of MAPK pathway, sod-3, ctl-1, gst-4 and other antioxidant genes. GPC can relieve symptoms related to aging in organisms. The aim of this study was to probe the effects of GPC on the longevity and stress resistance of the entomopathogenic nematode (EPN) Steinernema kraussei 0657L strain. The results showed that the lifespan of S. kraussei 0657L was significantly prolonged by 50mM GPC treatment, which was 54.55% longer than that of the control (0mM GPC). GPC significantly inhibited reactive oxygen species (ROS) and lipofuscin accumulation, but the body size and fecundity of S. kraussei 0657L had little changed. At the same time, the longevity of S. kraussei 0657L exposed to heat shock and UV-B radiation was significantly prolonged than that with no external stress. GPC supplementation increased the activity of antioxidant enzymes and corresponding gene expression. Under treatment with 50mM GPC, the activities of superoxide dismutase and catalase were increased by 1.90- and 4.13-fold, respectively, the expression of the sod-3 and ctl-1 genes was increased by 3.60- and 0.60-fold, respectively, and harmful reactive oxygen species were removed. In addition, the expression levels of the ins-18, skn-1, sek-1 and gst-4 genes related to the insulin/IGF-1 signaling pathway were upregulated 1.04-, 1.84-, 2.21- and 1.24-fold, respectively. These results indicate that GPC is mainly involved in the lifespan regulation of S. kraussei 0657L and plays an important role in resistance to external stress by activating the insulin/IGF-1 signaling pathway and downstream PI3K/MAPK kinase, creating a new idea for improving the commercial efficacy of S. kraussei. It also laid a theoretical foundation for its further efficient development and utilization in the field of biological control.

Arrival and survival of nematology in Canada

Summary This Forum article traces the initiation and development of research into plant-parasitic and entomopathogenic nematodes in Canada going back 170 years. It highlights the major achievements and the scientists involved up to the present day.

An Overview of the Biological Aspects, Nature of Damage and Strategies for Managing the Gram Pod Borer (Helicoverpa armigera Hubner) in Chickpea: A review

Gram pod borer, Helicoverpa armigera, a globally widespread and cosmopolitan insect pest, poses a significant threat to chickpea productivity worldwide. The effective management of this pest is paramount for ensuring sustainable chickpea yields. The life cycle of H. armigera spans approximately 4-5 weeks, progressing through egg, larvae, pupae and adult stages. During the initial 1st to 3rd instar larval phases, the insect primarily engages in feeding on leaves, twigs, and flowers. As the larvae advance to the 4th to 6th instar stages, they shift their focus to developing pods, creating holes or bores and consuming entire seeds. Yield losses of up to 90 percent may occur, contingent upon insect density and cultivar susceptibility. A comprehensive approach to sustainable chickpea pod borer management encompasses the utilization of resistant cultivars, strategic manipulation of sowing dates, maintaining optimal crop density, nutritional management, deployment of trap crops (such as maize, sunflower, sorghum, safflower, pigeon pea, okra and tomato), installation of animated bird perches and the application of biological control measures involving plant extracts, virus/bacteria-based insecticides and entomopathogenic nematodes. In instances of pod borer outbreaks, chemical insecticides are considered a last resort for farmers. However, the adoption of resistant cultivars, adherence to recommended cultural practices and the integration of biological control methods have proven to be more efficacious, economically viable, sustainable and environmentally friendly in the management of chickpea pod borer.

Harnessing nature's arsenal: Ochrobactrum bacteria metabolites in the battle against root- knot nematode – Insights from in vitro and molecular docking studies

Agricultural Productivity and plant health are threatened by the root-knot nematode. The use of biocontrol agents reduces the need for chemical nematicides and improves the general health of agricultural ecosystems by offering a more environmentally friendly and sustainable method of managing nematode infestations. Plant-parasitic nematodes can be efficiently managed with the use of entomopathogenic nematodes (EPNs), which are widely used biocontrol agents. This study focused on the nematicidal activity of the secondary metabolites present in the bacteria Ochrobactrum sp. identified in the EPN, Heterorhabditisindica against Root-Knot Nematode (Meloidogyne incognita). Its effect on egg hatching and survival of juveniles of root- knot nematode (RKN) was examined. The ethyl acetate component of the cell-free culture (CFC) filtrate of the Ochrobactrum sp. bacteria was tested at four different concentrations (25 %, 50 %, 75 % and 100 %) along with broth and distilled water as control. The bioactive compounds of Ochrobactrum sp. bacteria showed the highest suppression of M. incognita egg hatching (100 %) and juvenile mortality (100 %) at 100 % concentration within 24 h of incubation. In this study, unique metabolite compounds were identified through the Gas Chromatography- Mass Spectrometry (GC–MS) analysis, which were found to have anti- nematicidal activity. In light of this, molecular docking studies were conducted to determine the impact of biomolecules from Ochrobactrum sp. using significant proteins of M. incognita, such as calreticulin, sterol carrier protein 2, flavin-containing monooxygenase, pectate lyase, candidate secreted effector, oesophageal gland cell secretory protein and venom allergen-like protein. The results also showed that the biomolecules from Ochrobactrum sp. had a significant inhibitory effect on the different protein targets of M. incognita. 3-Epimacronine and Heraclenin were found to inhibit most of the chosen target protein. Among the targets, the docking analysis revealed that Heraclenin exhibited the highest binding affinity of −8.6 Kcal/mol with the target flavin- containing monooxygenase. Further, the in vitro evaluation of 3- Epimacronine confirmed their nematicidal activity against M. incognita at different concentrations. In light of this, the present study has raised awareness of the unique biomolecules of the bacterial symbiont Ochrobactrum sp. isolated from H. indica that have nematicidal properties.

Genetic toolbox for Photorhabdus and Xenorhabdus: pSEVA based heterologous expression systems and CRISPR/Cpf1 based genome editing for rapid natural product profiling

BackgroundBacteria of the genus Photorhabdus and Xenorhabdus are motile, Gram-negative bacteria that live in symbiosis with entomopathogenic nematodes. Due to their complex life cycle, they produce a large number of specialized metabolites (natural products) encoded in biosynthetic gene clusters (BGC). Genetic tools for Photorhabdus and Xenorhabdus have been rare and applicable to only a few strains. In the past, several tools have been developed for the activation of BGCs and the deletion of individual genes. However, these often have limited efficiency or are time consuming. Among the limitations, it is essential to have versatile expression systems and genome editing tools that could facilitate the practical work.ResultsIn the present study, we developed several expression vectors and a CRISPR-Cpf1 genome editing vector for genetic manipulations in Photorhabdus and Xenorhabdus using SEVA plasmids. The SEVA collection is based on modular vectors that allow exchangeability of different elements (e.g. origin of replication and antibiotic selection markers with the ability to insert desired sequences for different end applications). Initially, we tested different SEVA vectors containing the broad host range origins and three different resistance genes for kanamycin, gentamycin and chloramphenicol, respectively. We demonstrated that these vectors are replicative not only in well-known representatives, e.g. Photorhabdus laumondii TTO1, but also in other rarely described strains like Xenorhabdus sp. TS4. For our CRISPR/Cpf1-based system, we used the pSEVA231 backbone to delete not only small genes but also large parts of BGCs. Furthermore, we were able to activate and refactor BGCs to obtain high production titers of high value compounds such as safracin B, a semisynthetic precursor for the anti-cancer drug ET-743.ConclusionsThe results of this study provide new inducible expression vectors and a CRISPR/CPf1 encoding vector all based on the SEVA (Standard European Vector Architecture) collection, which can improve genetic manipulation and genome editing processes in Photorhabdus and Xenorhabdus.

Evaluating a Portable Method and Two Irrigation Drippers for Field Application of Entomopathogenic Nematodes

Entomopathogenic nematodes (EPNs) can be applied using drip irrigation systems. However, the choice of driplines and types of drippers significantly impacts the efficacy of field applications. This study investigated the performance of EPN applications using two common dripper types (katif and cylindrical drippers) under both pot and field conditions. The primary objective of the study was to optimize EPN applications and create a modular system in which driplines and drippers can be selected based on the target pest or plant. In our modular system, driplines were connected to a battery-powered backpack sprayer rather than an irrigation system. The efficacy of EPN applications was assessed on Galleria mellonella L. (Lepidoptera: Pyralidae) larvae at a commercial dose of approximately 50 IJs cm-2. The results revealed that only 60% of the nematodes were discharged from the cylindrical drippers, with 40% becoming trapped in the irrigation system. In contrast, over 90% of the nematodes were successfully discharged from the katif dripper. As a result, the katif dripper exhibited significantly higher larval mortality compared to all other application methods. These findings emphasize the substantial impact of the dripper type on EPN discharge, while also highlighting the applicability of the modular method for EPN applications.

Can we manage alien invasive insects without altering native soil faunal communities? A field trial on Popillia japonica

Biological and integrated pest control are key assets to environmentally friendly management of cropland. Use of entomopathogens against target pests is common, yet the effects of such released organisms on native, non-target invertebrates are currently poorly known. This is particularly true for relatively inconspicuous components of agroecosystems such as soil biological biota. Popillia japonica, a polyphagous alien invasive scarab beetle native to Japan, is now present in Europe where huge efforts are being conducted to control the pest and slow its spread. In particular, entomopathogenic nematodes and fungi have been used for larval control. Here we test the effects of those agents on both P. japonica larvae and non-target soil biota by comparing soil arthropod assemblages before and after treatment of field plots in an irrigated perennial meadow.Application of an indigenous strain of the nematode Heterorhabditis bacteriophora resulted in significant reduction in numbers of P. japonica larvae. In contrast, an indigenous strain of the entomopathogenic fungus Metarhizium robertsii failed to provide significant control. We found no evident effect on non-target edaphic arthropods under either treatment in comparison to untreated control plots. Some taxa, namely Collembola and Acarina, showed a disproportionate increase in treated plots, suggesting that some changes may occur in the long term, at least in particular arthropod groups. Our results suggest the selected strain of H. bacteriophora is an excellent candidate for managing P. japonica larvae with minimal adverse impact on non-target species and ecosystem functioning.

Entomopathogenic nematodes as an effective and sustainable alternative to control the fall armyworm in Africa.

The recent invasion of the fall armyworm (FAW), a voracious pest, into Africa and Asia has resulted in unprecedented increases in insecticide applications, especially in maize cultivation. The health and environmental hazards posed by these chemicals have prompted a call for alternative control practices. Entomopathogenic nematodes are highly lethal to the FAWs, but their application aboveground has been challenging. In this study, we report on season-long field trials with an innocuous biodegradable gel made from carboxymethyl cellulose containing local nematodes that we specifically developed to target the FAW. In several Rwandan maize fields with distinct climatic conditions and natural infestation rates, we compared armyworm presence and damage in control plots and plots that were treated with either our nematode gel formulation, a commercial liquid nematode formulation, or the commonly used contact insecticide cypermethrin. The treatments were applied to the whorl of each plant, which was repeated three to four times, at 2-week intervals, starting when the plants were still seedlings. Although all three treatments reduced leaf damage, only the gel formulation decreased caterpillar infestation by about 50% and yielded an additional ton of maize per hectare compared with untreated plots. Importantly, we believe that the use of nematodes can be cost-effective, since we used nematode doses across the whole season that were at least 3-fold lower than their normal application against belowground pests. The overall results imply that precisely formulated and easy-to-apply nematodes can be a highly effective, affordable, and sustainable alternative to insecticides for FAW control.

The role of protists, nematodes and mites as natural control agents of sandfly populations

The Phlebotomine sandflies (Diptera, Psychodidae) are hematophagous insects of immense medical and veterinary importance. Since World War II, the intensive use of chemicals to suppress and control sandfly populations resulted in development of insecticide resistance and resurgence among the sandfly populations worldwide. The use of chemicals also negatively impacted diverse non-target organisms, overall agroecosystem, crop productivity, human health etc. Due to the multiple adverse effects of the chemical compounds, more eco-friendly approaches have been evaluated. The application of entomopathogenic organisms such as nematodes, protists or mites as biocontrol agents has been vastly explored and applied in the field of forestry and agriculture. In comparison, only a little attention was given to blood-sucking insects such as sandflies. This review summarizes the findings related to the detection and use of entomopathogenic protists, nematodes, and mites in the field of biological control of sandflies. It highlights the potential of these organisms to be further explored and used for biocontrol of immature and adult stages of sandflies.

In Vitro Exploration of Entomopathogenic Nematodes as Potential Biocontrol Agents of Brinjal Borer Leucinodes Orbonalis Guenée (Lepidoptera: Crambidae)

Leucinodes orbonalis is a potential pest of eggplant, commonly known as fruit and shoot borer. Owing to its devastating nature, chemical pesticides are frequently applied and insecticide pressure is significantly higher in developing nations. Keeping the current situation in mind the most effective and practical strategy for managing insect pests found in humid and subtropical environments is the bio-control. Entomopathogenic nematodes, has been utilized against many pests for their effective management. Keeping in view the biocidal potential of entomopathogenic nematodes, the current study was planned to explore the biocidal potential of Steinernema and Heterorhabditis, two significant genera of entomopathogenic nematodes against L. orbonalis. White trap extraction technique was used to isolate nematodes from several insect larvae. Four discrete concentrations of entomopathogenic nematodes viz. 60, 90, 120, and 150 infective juveniles per larvae were applied on larval stages. The virulence trial was followed by completely randomized block design. Multiple comparisons showed that among both the tested nematodes H. bacteriophora induced significant 81.33% mortality corresponding to 150 IJs/larva after 72 h of exposure as compared to S. glaseri. In the view of current research, entomopathogenic nematodes are recommended to be used in integrated pest management program for the management of insect pests.

Effectiveness of Two Entomopathogenic Nematodes (Nematoda: Rhabditida) Populations in Controlling Fall Armyworm [(Spodoptera Frugiperda) Lepidoptera: Noctuidae] on Maize

The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), is a recent invasive pest significantly impacting maize production and food security in sub-Saharan Africa. While chemical insecticides have offered the most effective control in Ghana, their detrimental effects on human health and the environment necessitate the urgent exploration of alternative, environmentally friendly options. This study compared two entomopathogenic nematodes populations, Heterorhabditis bacteriophora and Steinernema carpocapsae, against a control group (no application) for their efficacy in managing fall armyworm on maize. In the second experiment, S. carpocapsae significantly outperformed both H. bacteriophora and the control in terms of seed weight, achieving a 12.9% increase over the former and a remarkable ninefold improvement over the latter. The first experiment, however, showed no significant difference in seed yield (59 g, 32 g, 2 g) between the two nematode treatments, S. carpocapsae demonstrated the highest yield within this group. Notably, the control group exhibited the highest degree of foliage damage (4.7; 5.0) on a 1-5 scale throughout the study period. Overall, this study demonstrates the superior efficacy of S. carpocapsae compared to H. bacteriophora in controlling fall armyworm on maize. These findings provide valuable understandings for advancing the practical application of entomopathogenic nematodes as a sustainable and eco-friendly biocontrol measure against this devastating pest, contributing to enhanced food security in sub-Saharan Africa.

Virulence of Entomopathogenic Nematodes and their Symbiotic Bacteria against Insect Pests, with Special Reference to Agrotis ipsilon (Lepidoptera: Noctuidae): A Comprehensive Review.

Virulence of Entomopathogenic Nematodes and their Symbiotic Bacteria against Insect Pests, with Special Reference to Agrotis ipsilon (Lepidoptera: Noctuidae): A Comprehensive Review.