Control Of Fall Armyworm Research Articles

Comparative Efficacy of Insecticides against Fall Armyworm (Spodoptera frugiperda) in Baby Corn

Aims: The fall armyworm (Spodoptera frugiperda) is a major pest threatening baby corn production, significantly impacting yield and profitability. This study aimed to evaluate the efficacy of various insecticides and their combinations in managing fall armyworm populations while ensuring sustainable crop production. Study Design: Randomized Block Design (RBD). Place and Duration of Study: Maize Research Centre, Agricultural Research Institute, Rajendranagar, Hyderabad, during the rabi season of 2022–2023. Methodology: Field experiments were conducted to assess the impact of seed treatments, foliar sprays, and their combinations on pest control, crop performance, and natural enemy conservation. The experiment followed a Randomized Block Design with three replications and eight treatments, T1 (tetraniliprole 480 FS and cyantraniliprole 10.26% OD spray, T2 (cyantraniliprole 19.8% + thiamethoxam 19.8% FS and spinetoram spray), T3 (cyantraniliprole 600 FS and chlorantraniliprole 9.3% + lambda-Cyhalothrin 4.6% ZC spray), T₄ (chlorantraniliprole 18.5% SC), T₅ (emamectin Benzoate 5% SG), T₆ (flubendiamide 480 SC), T₇ (dimethoate 30 EC) and T8 (untreated control). Insecticides were applied twice at a 14-day interval. Observations on leaf injury rating (LIR) and percent infestation were recorded using the standard 1–9 scale given by modified Davis and Williams. Pre-treatment observations were taken one day before spraying, and post-treatment observations were recorded at 7 and 14 days after each application. Parameters such as percent reduction over control, dehusked cob yield, green fodder yield, and cost-benefit ratio were calculated to evaluate treatment efficacy. Results: Results indicated that seed treatments followed by foliar sprays provided superior control of fall armyworm, with T2 (cyantraniliprole 19.8% + thiamethoxam 19.8% FS and spinetoram spray) demonstrating the lowest leaf injury ratings and highest yield benefits. T3 (cyantraniliprole 600 FS and chlorantraniliprole 9.3% + lambda cyhalothrin 4.6% ZC spray) exhibited comparable performance, followed by T1, T4, T5, T6 and T7. The study underscores the importance of integrating effective pest management strategies to enhance baby corn productivity and profitability. Conclusion: The study highlights the effectiveness of integrating seed treatments with foliar sprays for managing S. frugiperda in baby corn. T3 and T2 emerged as the most effective treatments, both in terms of pest control and economic viability, underscoring their potential for sustainable pest management and enhanced crop productivity.

Maize plants can recover from fall armyworm damage under optimum crop production conditions in humid tropical agro-ecologies.

Farmers in Africa perceive the impact of fall armyworm (FAW) on maize to be significant, but field assessments have shown that yield losses are not significant enough to warrant pesticide interventions. This suggests that relationships between the crop stages, time, and duration of attack can affect the yield. Therefore, assessing the plant's recovery from damage using individual plants based on defoliation levels could guide whether and when pesticides should be applied. To study this, we selected 120 labeled maize plants corresponding to six levels of FAW defoliation, replicated 20 times, based on an initial damage rating. The rating scale ranged from 1 (no defoliation) to 5 (>75% defoliation) during four planting seasons. Plants with a rating scale of 1 were replicated and treated with a chemical insecticide to keep them undefoliated, and that served as a control. Damage severity was recorded weekly on all plants, starting from emergence until maturity, using the same damage rating scale. Results showed that damage severity varied significantly among different defoliation levels during all seasons. Higher levels of defoliation during dry seasons resulted in significant yield loss only for plants with damage levels 4 and 5, with damage severity ranging from 38.7% to 57.5%. These results indicate that FAW control is unnecessary in the rainy season. In contrast, pesticide interventions should be envisaged in seasons of erratic rainfall, with a significant defoliation threshold level of around 50%, occurring at 8 and 5wk after planting weeks after planting, respectively for the early and late dry season.

Comparative Study of the Efficacy of Two Biological Insecticides (Azadirachta indica and Bacillus thuringiensis) and a Chemical insecticide (Diflubenzuron WP) against Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) in Maize Crop, Western Bur

Aims: This study aimed at comparing the biological efficacy of Diflubenzuron WP, a chemical insecticide, and two biopesticides, one based on neem oil (Azadirachta indica) and an entomopathogen (Bacillus thuringiensis) against the fall armyworm on maize. Place and Duration of Study: The work was carried out on the irrigated scheme of Bama, western Burkina Faso during the 2022 and 2023 wet seasons. Methodology: The experimental design was a Fisher block with 4 treatments: T0: untreated or control; T1: Bacillus thuringiensis; T2: neem oil; T3: Diflubenzuron WP, in 4 replications. Entomological observations focused on the score and severity of attacks, as well as the pest's infestations rate. Results: The results showed that the different insecticides tested over the two wet seasons of 2022 and 2023 induced better control of S. frugiperda populations, with larval density being kept lower with the treatment of Diflubenzuron WP (4.25±1.2%), neem oil (14.28±1.6%) and Bacillus thuringiensis (24.5±3.2%). The insect damage severity rates and scores of damaged ears were also low for the three treatments respectively (1.09±0.2, 0.9±0.26 and 0.27±0.71) over the two cropping seasons. Diflubenzuron WP insecticide treatment not only reduced pest pressure, but also significantly improved maize yield. No surprisingly the highest yield (5.14 t/ha) was recorded with Diflubenzuron WP, followed by neem oil (4.62kg/ha) and finally Bacillus thuringiensis (3.92kg/ha). Conclusion: Further studies are needed to determine the optimal doses of neem oil and Bt for the control of Fall Armyworm. Neem oil can be considered as a good alternative to a chemical insecticide like Diflubenzuron WP.

Monitoring of the Fall Armyworm (Spodoptera frugiperda Walker) Moth for the Determination of Efficient Chemical Control in Zea mays L.

Objective: To determine the population dynamics of the fall armyworm (FAW), identify the critical period of highest infestation and to determine the number of agrochemicals applications for its control. Design/methodology/approach: A monitoring and capture of male FAW moths was conducted using plastic traps with sexual attraction pheromones. A daily count of captured moths was performed during the crop season, the data were plotted to determine the period of highest infestation and the optimal timing for chemical control. Additionally, the number of insecticide applications for FAW control was evaluated, with treatments including none (T0), one (T1), two (T2), three (T3), and four (T4) applications. A randomized complete block design with nine repetitions was used. Before each application, the number of plants with visible damage and its intensity were counted using the Davis visual scale. Statistical analysis of the measured variables was conducted. Results: The results showed that moths were evenly distributed across the planted surface, and two periods of higher infestation were identified: between 32 to 35 and 70 to 76 days after planting, respectively. The biological cycle of the FAW was between 38 to 41 days. The analysis of variance showed statistical differences (p ≤ 0.001) among the treatments. Findings/conclusions: Using plastic traps with sexual attraction pheromones is an efficient method for capturing, monitoring, reducing the population, estimate the length of the biological cycle, and identifying the highest infestation period of the FAW. Moreover, two insecticide applications during the periods of highest infestation resulted in optimal control of FAW.

Evaluation of the Maize - False basil Cultural Association in the Fight against the Fall Armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)

In Ivory Coast, maize (Zea mays L.) is the second most cultivated cereal after rice. Despite this, maize cultivation is limited by pest pressures. Apart from the usual pests, a new enemy has arrived on the continent, the fall armyworm, Spodoptera frugiperda. To control this pest, farmers use pesticides, which are not only expensive, but also pose risks to human health and the environment. The objective of this study is to find an alternative solution to chemical control through the cultivation of maize-Ocimum gratissimum (False basil) in two ways. The first consisted in planting False basil around the maize plot as a barrier plant (P1). The second consisted of alternating maize plants with False basil plants (P2). The experimental design used was a one-factor randomized FISHER block with three treatments. The efficacy of the two association modalities was compared to that of control which was maize crop only. The results showed better control of fall armyworm in the combination than control. Of the two combination treatments, it was the P1 treatment that was effective against S. frugiperda compared to the P2 treatment and the control. Thus the infestation rate of treatment P1 (33 %) was lower than that of treatment P2 (50 %) followed by the control (70 %). In addition, it was the P1 treatment that harbored fewer armyworms (8 larvae) compared to the P2 treatment (22 larvae) and the control (35 larvae). The maize-False basil crop combination therefore appears to be beneficial than pure crops as it significantly reduces the infestation rate, damage level and harbors less fall armyworm population.

Linking demography and food consumption to project population growth and damage potential of Spodoptera frugiperda in India

Abstract The fall armyworm, Spodoptera frugiperda (J. E. Smith), identified as an invasive pest worldwide, has severely threatened agricultural production and food security in India. To formulate eco‐friendly integrated pest management strategies for S. frugiperda in its new invasive habitat, the basic knowledge about demographic parameters and damage potential of this pest is crucial. The effects of five host crops viz. maize (Zea mays L.), popcorn (Zea mays everta Sturt), sweet corn (Zea mays saccharata Sturt), sorghum (Sorghum bicolor (L.)) and soybean (Glycine max (L.) Merr.) on the development and food consumption of S. frugiperda were examined. Population projection curves based on life table and consumption rates were drawn on different hosts using computer simulation. The pre‐adult development of S. frugiperda was fastest on popcorn (28.02 days), maize (28.04 days) and sweet corn (28.31 days) but slowest on soybean (34.83 days). The highest net reproductive rate, intrinsic rate of increase and finite rate of increase were observed on maize. The feeding potential of S. frugiperda was also highest on maize. The maximum consumption of the sixth larval instar was observed on maize (19470.47 mm2) while lowest on soybean (9033.67 mm2). In the simulation period of 90 days, the fastest growth of S. frugiperda was expected on maize, popcorn and sweet corn while the slowest on soybean. High larval and pupal survival recorded on the non‐maize hosts (sorghum and soybean) reflects that fall armyworm could be an obstacle in their production as well as in the success of maize‐soybean intercropping system. Simulations based on age‐stage, two‐sex life table could be helpful in predicting the most appropriate time for the pesticide application as well as augmentative releases of egg and larval parasitoids for the control of fall armyworm.

Integrated developmental and green social work field education to control fall armyworm Infestation in maize crops in Malawi

In Malawi, fall armyworm (FAW) infestation in maize crops is a problem of public importance as it reduces maize yields and exacerbates household food insecurity. In addition to pest resistance, the use of synthetic pesticides to control FAW negatively affects the health of farmers and the environment. Biochemical pesticides from plants contain naturally non-toxic chemotypes and are effective in controlling pests. Tephrosia vogelii plants contain these bioactive phytocompounds that have pesticidal properties. Geographical location and plant species influence the occurrence of phytocompounds in Tephrosia vogelii. Farmers in Sub Sahara-Africa are using Tephrosia vogelii as a pesticide but there are mixed research findings regarding its effectiveness in controlling FAW pests. This study was informed by developmental and Green Social Work frameworks to compare the effectiveness of Tephrosia vogelii leaves extracts, Belt 480 SC, and soap solution in controlling FAW in maize gardens. The study employed a randomized complete block design with four replication gardens and was conducted from November 2022 to March 2023. A social work field education student was assigned to coordinate the project. The study affirmed that the sampled Tephrosia vogelii leaf extracts contained pesticidal chemotypes. The results of field gardens suggest that Tephrosia vogelii leaf extracts have similar potency to Belt SC 480 chemical pesticide. It has been identified that Boom detergent soap is not as effective as Tephrosia vogelii leaf extracts. The study has social work field education implications for empowering practicum students to gain community mobilization skillsets, to participate in environmental justice advocacy, and to uphold social work values.

Morphological characterization and distribution of antennal sensilla of Spodoptera frugiperda (Lepidoptera: Noctuidae) using scanning electron microscopy.

The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is a globally significant agricultural pest, causing severe damage to corn production in China. Chemical odor-based trapping is a major approach for FAW control, making it essential to understand the FAW antennal sensillum types to enhance development of effective chemical odor attractants. In this study, we comprehensively examined the antennal sensilla types of FAW, identifying eight types and two subtypes, including Böhm's bristles, sensilla trichoidea, sensilla chaetica (I and II), sensilla coeloconica, sensilla styloconica, sensilla squamiformia (I and II), sensilla auricillica, and sensilla basiconica. Sensilla chaetica II, and sensilla squamiformia II are reported for the first time for FAW in this study. Detailed low-voltage field emission scanning electron microscope (LVSEM) images and descriptions are provided for each sensillum type. This study provides the morphological information to aid in conducting antennal sensillum neurophysiological tests on FAW. RESEARCH HIGHLIGHTS: The types of sensilla of fall armyworm were examined, identifying eight types and two subtypes, including Böhm's bristles, sensilla trichoidea, sensilla chaetica (I and II), sensilla coeloconica, sensilla styloconica, sensilla squamiformia (I and II), sensilla auricillica, and sensilla basiconica. Detailed low-voltage field emission scanning electron microscope images and descriptions were provided for each sensillum type.

Dusting Metarhizium rileyi conidia with a drone for controlling fall armyworm and soybean looper in maize and soybean fields

Dusting Metarhizium rileyi conidia with a drone for controlling fall armyworm and soybean looper in maize and soybean fields

CRISPR/Cas9-mediated genome editing technique to control fall armyworm (Spodoptera frugiperda) in crop plants with special reference to maize.

Fall Armyworm imposes a major risk to agricultural losses. Insecticides have historically been used to manage its infestations, but it eventually becomes resistant to them. To combat the pest, a more recent strategy based on the use of transgenic maize that expresses Bt proteins such as Cry1F from the bacteria has been used. Nonetheless, there have been numerous reports of Cry1F maize resistance in FAW populations. Nowadays, the more effective and less time-consuming genome editing method known as CRISPR/Cas9 technology has gradually supplanted these various breeding techniques. This method successfully edits the genomes of various insects, including Spodoptera frugiperda. On the other hand, this new technique can change an insect's DNA to overcome its tolerance to specific insecticides or to generate a gene drive. The production of plant cultivars resistant to fall armyworms holds great potential for the sustainable management of this pest, given the swift advancement of CRISPR/Cas9 technology and its varied uses. Thus, this review article discussed and critically assessed the use of CRISPR/Cas9 genome-editing technology in long-term fall armyworm pest management. However, this review study focuses primarily on the mechanism of the CRISPR-Cas9 system in both crop plants and insects for FAW management.

Larvicidal and feeding deterrent properties of extracts from Dieffenbachia maculata (Dumb cane) against Spodoptera frugiperda in maize (Zea mays)

This study examined the larvicidal and feeding deterrent properties of extracts from Dieffenbachia maculata against Spodoptera frugiperda (Fall army worm) in growing maize. A 9 m x 7 m space in the green house was divided into forty-two plots of 1 m by 0.75 m with 0.5 m discard between rows. This is to allow for a 2 x 3 x 4 factorial experiment replicated three times. Maize seeds were sown at two seeds per hole at a spacing of 90 cm by 60cm in each plot. Each plot was barricaded with wire mesh to prevent the migration of larvae from plot to plot. The irrigation system in the greenhouse supplied equal volume of water at the base of the maize seedlings every morning. Infested maize plants were treated with different Dumb cane plant extracts at the concentration of 25ml/l and30ml/l along with positive and negative controls. (The positive control was treated with Cypermethrine at 3l/ha) to compare the effect of concentrations on the fall army worm activity. In this experiment, the numbers of leaves affected was assessed every week and recorded. Leave perforation index was calculated. Dead armyworms were observed by prodding the larvae for movement and were recorded. Plant vigour was obtained by measuring plant height and the number of leaves formed. Effect of the worm on yield was determined by comparing total yield from sampled maize plants and this was compared to expected yield from the variety of maize used for the research. The positive control group exhibited a significantly lower level of infestation after treatment with a corresponding yield increase, (16.06% and 80.14%) respectively when compared to the treated groups. Similarly, leave extract using acetone at 30ml record significantly better results with 17.73% level of infestation after treatment application and 66.44% yield increase. This was closely followed by leaf extract using methanol at 30ml with significantly lower level of infestation and increased yield respectively. (21.35% and 60.42%). Conversely, the lowest value was recorded for the negative control. Among the extract treatments, the leaf extract using acetone at 30ml showed the highest efficacy in reducing infestation levels and demonstrated the most significant increase in maize yield. In this study, it was observed that application of the 30ml leaf extract of Dumb cane using acetone was effective and significantly increased army worm larval mortality, reduced leaf damage, and increased maize grain yield compared to the untreated control. The results indicated that the extracts from dumb cane leaves and stems exhibited promising capacity in the control of Fall army worm in maize. Further research is warranted to optimize the application protocols and evaluate any residual effects of the extracts on maize grain and ecosystem dynamics

TOXICITY OF SOME INSECTICIDES AND THEIR SUBLETHAL EFFECTS ON NUTRITIONAL INDICES OF FALL ARMYWORM IN SWEET CORN PLANT

Corn is a vital cereal crop in Bangladesh, significantly contributing to food security and economy. However, the fall armyworm Spodoptera frugiperda, poses a severe threat to corn cultivation. This study evaluates the toxicity of four insecticides and their effect on the nutritional indices of fall armyworm. Experiment was conducted from November 2022 to April 2023 with sweet corn variety BU Misty Vutta 1 at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh. In this research four insecticides: Winmax 40 WDG, Ripcord 10 EC, Marshal 20 EC, and Shobicron 425 EC, were tested on fall armyworm larvae at multiple concentrations. The mortality of fall armyworm larvae was observed at 24, 48, 72, and 96 hours after treatment. Results indicated significant differences in larval mortality across treatments, with Shobicron 425 EC showing the highest mortality rate (100% at 72 hours after treatment), while Winmax 40 WDG showed the lowest. The median lethal concentration (LC50) and lethal concentration for 95% mortality (LC95) values supported the findings, with Shobicron 425 EC demonstrating superior efficacy. Additionally, Shobicron 425 EC resulted in the lowest food consumption (0.1), consumption index (0.2), Approximate digestibility (19.5%), Efficiency of conversion of ingested food (3.9%) and Efficiency of conversion of digested food (1.1%). The study concludes that Shobicron 425 EC is the most effective insecticide for controlling fall armyworm in sweet corn, suggesting its potential for integrated pest management strategies.

Record of natural enemies of invasive fall armyworm, <i>Spodoptera frugiperda</i> (J. E. Smith) (Lepidoptera: Noctuidae) in fodder maize ecosystem in Goa

Fall Armyworm (FAW), Spodoptera frugiperda (J. E. Smith), a recent invasive pest, poses a serious threat to maize production and productivity in India. Very little information is available on FAW indigenous natural enemies in authors are ecosystems. Hence, the present study assessed and documented the native natural enemies of FAW in the fodder maize ecosystem of Goa. Under field conditions, various life stages of FAW were attacked by 22 species of native natural enemies comprising two egg parasitoids, five larval parasitoids, eleven predators, and four entomopathogens. The field egg parasitism of Trichogramma chilonis Ishii and Telenomus remus Nixon was 13.90% and 29.37%, respectively. Among the egg parasitoids, T. remus was the dominant one. With a parasitism rate of 6.58%, Campoletis chlorideae Uchida was the most prevalent larval parasitoid. Eleven different species of predators were found predating on FAW. Among the predators, the rove beetle, Paederus fuscipes Curtis was the most abundant, with 1-2 adults per plant. Four entomopathogens viz., Metarhizium rileyi (Farlow), Bacillus sp., Spodoptera frugiperda nuclear polyhedrosis virus, and entomopathogenic nematode, Hexamermis sp. were found infecting the FAW larvae. The present study reports the indigenous natural enemies associated with FAW in fodder maize. These native natural enemies must be conserved and exploited for the biological control of FAW.

Area-wide pest management and prospects for fall armyworm control on smallholder farms in Africa: A review

Area-wide pest management and prospects for fall armyworm control on smallholder farms in Africa: A review

Toxicity of Cry- and Vip3Aa-Class Proteins and Their Interactions against Spodoptera frugiperda (Lepidoptera: Noctuidae).

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is one of the most important insect pests affecting corn crops worldwide. Although planting transgenic corn expressing Bacillus thuringiensis (Bt) toxins has been approved as being effective against FAW, its populations' resistance to Bt crops has emerged in different locations around the world. Therefore, it is important to understand the interaction between different Bt proteins, thereby delaying the development of resistance. In this study, we performed diet-overlay bioassays to evaluate the toxicity of Cry1Ab, Cry1Ac, Cry1B, Cry1Ca, Cry1F, Cry2Aa, Cry2Ab, Vip3Aa11, Vip3Aa19, and Vip3Aa20, as well as the interaction between Cry1Ab-, Cry1F-, Cry2Ab-, and Vip3Aa-class proteins against FAW. According to our results, the LC50 values of Bt proteins varied from 12.62 ng/cm2 to >9000 ng/cm2 (protein/diet), among which the Vip3Aa class had the best insecticidal effect. The combination of Cry1Ab and Vip3Aa11 exhibited additive effects at a 5:1 ratio. Cry1F and Vip3Aa11 combinations exhibited additive effects at 1:1, 1:2, and 5:1 ratios. The combination of Cry1F and Vip3Aa19 showed an antagonistic effect when the ratio was 1:1 and an additive effect when the ratio was 1:2, 2:1, 1:5, and 5:1. Additionally, the combinations of Cry1F and Vip3Aa20 showed antagonistic effects at 1:2 and 5:1 ratios and additive effects at 1:1 and 2:1 ratios. In addition to the above combinations, which had additive or antagonistic effects, other combinations exhibited synergistic effects, with variations in synergistic factors (SFs). These results can be applied to the establishment of new pyramided transgenic crops with suitable candidates, providing a basis for FAW control and resistance management strategies.

Biorationals and Synthetic Insecticides for Controlling Fall Armyworm and Their Influence on the Abundance and Diversity of Parasitoids

Spodoptera frugiperda (fall armyworm, FAW) is a significant economic pest of maize in Uganda. Many Ugandan maize farmers employ synthetic insecticides as their main form of control despite the negative impacts of these chemicals. We tested the effectiveness of Beauveria bassiana; General Biopesticide Cocktail (mixture of B. bassiana, M. anisopliae, Isaria fumosoroseus, Lecanicillium lecani and Purporeocillium lilacanus three strains of Metarhizium anisopliae, Nimbecidine® (azadirachtin 0.03%EC), and Roket® (cypermethrin 4% and profenofos 40%); and Amdocs® (emamectin benzoate 2% and abamectin 1%) on fall armyworm and parasitoids, respectively, in 2020 and 2021. The treatments with the greatest decrease in leaf damage and infestation were Amdocs® and Roket®, followed by Nimbecidine®. The biopesticides were not always more effective than the untreated control, though; their efficacy was often lower than that of the synthetic and botanical pesticides. We recovered one egg parasitoid, Telenomus remus, and seven egg and egg-larval parasitoids (Coccygidium luteum, Coccygidium sp., Cotesia icipe, Chelonus sp., Micranisa sp., Charops cf. diversipes, and an unidentified Tachinidae). Among these, C. cf diversipes, Chelonus sp., C. luteum, C. icipe and the Tachinidae were the most abundant. Parasitism was low, averaging 10% for egg masses and 5.3% for larvae. Application of synthetic pesticides and Nimbecidine® often resulted in higher yield when compared with the untreated control. In general, a low population of parasitoids was observed. Although the parasitoid population reduced in plots treated with Amdocs® and Roket®, the percentage of parasitism of FAW was not affected. In some instances, higher yields were realized in untreated control when compared with the treated plots. Pest management practices more compatible with biological control need to be considered for the management of fall armyworm.

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.

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.

Gene Cloning, Heterologous Expression, and In Silico Analysis of Chitinase B from Serratia marcescens for Biocontrol of Spodoptera frugiperda Larvae Infesting Maize Crops.

Spodoptera frugiperda, the fall armyworm (FAW), is a highly invasive polyphagous insect pest that is considered a source of severe economic losses to agricultural production. Currently, the majority of chemical insecticides pose tremendous threats to humans and animals besides insect resistance. Thus, there is an urgent need to develop new pest management strategies with more specificity, efficiency, and sustainability. Chitin-degrading enzymes, including chitinases, are promising agents which may contribute to FAW control. Chitinase-producing microorganisms are reported normally in bacteria and fungi. In the present study, Serratia marcescens was successfully isolated and identified from the larvae of Spodoptera frugiperda. The bacterial strain NRC408 displayed the highest chitinase enzyme activity of 250 units per milligram of protein. Subsequently, the chitinase gene was cloned and heterologously expressed in E. coli BL21 (DE3). Recombinant chitinase B was overproduced to 2.5-fold, driven by the T7 expression system. Recombinant chitinase B was evaluated for its efficacy as an insecticidal bioagent against S. frugiperda larvae, which induced significant alteration in subsequent developmental stages and conspicuous malformations. Additionally, our study highlights that in silico analyses of the anticipated protein encoded by the chitinase gene (ChiB) offered improved predictions for enzyme binding and catalytic activity. The effectiveness of (ChiB) against S. frugiperda was evaluated in laboratory and controlled field conditions. The results indicated significant mortality, disturbed development, different induced malformations, and a reduction in larval populations. Thus, the current study consequently recommends chitinase B for the first time to control FAW.

Evaluation of farmers friendly IPM modules for the management of fall armyworm, Spodoptera frugiperda (JE Smith) in maize in the hot semiarid region of India

Invasive alien species (IAS) pose a severe threat to global agriculture, with their impact projected to escalate due to climate change and expanding international trade. The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), a native of the Americas, has rapidly spread across various continents, causing significant damage to several food crops, especially maize. Integrated pest management (IPM) programs are vital for sustainable FAW control, combining multiple strategies for sustainable results. Over three consecutive years, 2019–20, 2020–21 and 2021–22, the field demonstrations were conducted in semiarid regions of India, testing a four-component IPM approach viz., pheromone traps, microbial, botanicals and ETL based applications of insecticides against farmers' practices (sole insecticide application). IPM implementation led to substantial reductions in FAW infestation. Furthermore, egg mass and larvae infestations were significantly lower in IPM-adopted villages compared to conventional practices. Pheromone-based monitoring demonstrated a consistent reduction in adult moth populations. The lowest technology gap (10.42), extension gap (8.33) and technology index (12.25) was recorded during 2020–21. The adoption of IPM led to increased maize yields (17.49, 12.62 and 24.87% over control), higher net returns (919, 906.20 and 992.93 USD), and favourable benefit–cost ratios (2.74, 2.39 and 2.33) compared to conventional practices respectively during 2019–20, 2020–21 and 2021–22. The economic viability of IPM strategies was evident across three consecutive years, confirming their potential for sustainable FAW management in the semiarid region of India. These strategies hold promise for adoption in other parts of the world sharing similar climatic conditions.