Integration of Selective Insecticides with Metarhizium anisopliae for Sustainable Management of Fall Armyworm, Spodoptera frugiperda (J.E. Smith) in Maize

Evaluation of selected entomopathogenic fungi and pheromones for the control of fall armyworm (Spodoptera frugiperda) on maize in Baghdad

Fall armyworm, Spodoptera frugiperda, is a major maize pest requiring effective and environmentally sustainable management strategies. This study evaluated the efficacy of Beauveria bassiana, Metarhizium anisopliae, pheromone traps, and their integration under field conditions in Iraq. Significant differences (P ≤ 0.05) were observed among treatments for larval density, plant infestation, and damage severity. The untreated control recorded the highest larval density (3.46 larvae plant-1), infestation (52.4%), and damage severity (2.86). In contrast, the combined application of B. bassiana + pheromone traps provided the greatest suppression, reducing larval density to 0.92 larvae plant-1 (73.4% reduction), infestation to 18.7% (64.3% reduction), and damage severity to 1.21 (57.7% reduction) relative to the control. Among individual treatments, B. bassiana was more effective than M. anisopliae, reducing larval density to 1.35 larvae plant-1, infestation to 24.5%, and damage severity to 1.48. Pheromone traps alone provided moderate suppression, with corresponding values of 2.14 larvae plant-1, 33.6%, and 1.94, respectively. The superior performance of the combined treatment was attributed to simultaneous suppression of larvae by fungal infection and adult males through pheromone trapping, although synergistic interaction was not statistically established. Overall, integrating entomopathogenic fungi with pheromone-based control showed strong potential for reducing S. frugiperda populations and maize damage while supporting sustainable integrated pest management under field conditions.

Assessment of Insecticidal Compatibility of Metarhizium anisopliae Isolates against Diamondback Moth (Plutella xylostella L.)

The diamondback moth, Plutella xylostella (L.), is a serious insect pest of cruciferous crops and has developed widespread resistance to several insecticides, necessitating the development of alternative management strategies. The present investigation was undertaken to determine the compatibility of different Metarhizium anisopliae isolates with selected insecticides and to evaluate their efficacy against P. xylostella. The experiment was conducted under laboratory conditions using a two-factor completely randomised design (CRD) at the Biocontrol Research and Production Centre (BRPC), Department of Entomology, College of Agriculture, Jawaharlal Nehru Krishi Vishwa Vidyalaya (JNKVV), Jabalpur, Madhya Pradesh, during 2024–2025. Five isolates of M. anisopliae were tested in combination with spinosad, indoxacarb, fipronil and emamectin benzoate. Compatibility was assessed on the basis of radial mycelial growth, percentage inhibition, spore production and spore viability, while insecticidal activity was determined against third-instar larvae of P. xylostella. Significant variation was observed among the fungal isolates, insecticides and their interactions. ITCC-6895 exhibited the greatest radial growth (78.96 mm at 7 DAI), whereas NBAII Ma-6 showed the lowest. Emamectin benzoate exhibited the greatest compatibility with the fungal isolates and produced synergistic interactions with NBAIR Ma-56b and Ma LOCAL. Ma LOCAL recorded the highest spore viability (97.10%), while both Ma LOCAL and NBAII Ma-6 produced the highest mean spore count (1.54 × 10⁸ spores mL⁻¹). In the laboratory bioassays, all insecticides resulted in complete larval mortality after 120 h, whereas ITCC-6895 recorded the highest average mortality (94.83%) among the fungal isolates. NBAIR Ma-56b and Ma LOCAL showed highly compatible interactions with emamectin benzoate, as indicated by negative percentage inhibition values. These findings indicate that compatible combinations of M. anisopliae, particularly ITCC-6895 and Ma LOCAL, with emamectin benzoate can improve the management of P. xylostella as part of an integrated pest management programme. Overall, compatible combinations of M. anisopliae with selective insecticides demonstrated strong potential for the environmentally sound management of P. xylostella.

Spodoptera frugiperda (Lepidoptera: Noctuidae) infestation in maize and its management using mulberry organic residues

Introduction. Soil incorporation of Morus alba biomass mitigates Spodoptera frugiperda damage in maize, through the release of bioactive secondary metabolites with antifeedant properties. Objective. To characterize farmer perceptions of Spodoptera frugiperda severity and evaluate the efficacy of Morus alba residue incorporation as a sustainable management strategy in the Mocache canton, Ecuador. Materials and methods. The research was conducted between December 2023 and May 2024. The study consisted of two phases: a survey of farmers and a field experiment. The farmers were surveyed regarding the agronomic practices they implemented to manage S. frugiperda. The experiment was conducted in the locality of Jesús del Gran Poder and consisted of three treatments: i) a control without pest management or residue incorporation (Control); ii) soil incorporation of 1 t ha⁻¹ of a mixture of maize residues (80 %) and fragmented mulberry cv. Tigreada (20 %) (M+M); and iii) the application of methomyl insecticide. The variables of severity of infestation and agricultural yield were evaluated. A randomized complete block design with three treatments and three replicates was employed. Treatment means were compared using Duncan’s multiple range test (α = 0.05). Statistical processing was performed using the InfoStat package. Results. Residue incorporation reduced severe foliar damage (grades 4-5) to 29.6%, significantly lower than the control (36.1%; p < 0.05). Grain yield reached 4.1 t ha⁻¹ with residues, statistically comparable to methomyl (4.6 t ha⁻¹) and 17 % higher than the control (3.5 t ha⁻¹). Conclusions. The high perception of severity of S. frugiperda by farmers corresponds with high levels of infestation, associated with inadequate agronomic practices and poor technical training. The maize and mulberry residues incorporated into the soil reduce severity and allow obtaining yields like the insecticide, validating its effectiveness as a management alternative in Ecuador and similar regions.

Effects of Mesosphaerum suaveolens leaves oil Emulsifiable Concentrate and Lamda-cyhalothrin on arthropods associated with Cucumis melo in Wukari, Nigeria

Unravelling the efficacy and reproductive potential of newly discovered entomopathogenic nematodes, Steinernema indicum and Steinernema shori against Spodoptera frugiperda in maize

Spodoptera frugiperda (J.E. Smith), commonly known as the fall armyworm, is one of the most destructive insect pests of maize worldwide, causing substantial economic losses. Its widespread occurrence and increasing resistance to conventional insecticides have intensified the need for effective and sustainable management approaches. Reliance on chemical pesticides not only accelerates resistance development but also poses significant risks to the environment and beneficial non-target organisms. Consequently, environmentally friendly alternatives, particularly biological control strategies, are gaining importance as viable components of integrated pest management programs for this pest. In the present study, the susceptibility of the larval and pupal stages of S. frugiperda to two indigenous entomopathogenic nematode (EPN) species, Steinernema shori NBAIRS80 and Steinernema indicum NBAIRS58, was assessed. The effect of different concentrations of infective juveniles (IJs) of S. indicum and S. shori on their reproductive potential in third-instar S. frugiperda larvae was also investigated under laboratory conditions. Furthermore, the efficacy of S. indicum and S. shori against S. frugiperda was evaluated under both pot and field conditions. Results revealed that under laboratory conditions, both EPN species exhibited high virulence against third, fourth, and sixth instar larvae, achieving 100.0% mortality as the concentration increased from 20 to 420 IJs larva -1 . However, S. shori caused significantly higher mortality than S. indicum . A similar trend was recorded in pupae, where S. shori caused 81.0% mortality compared to 65.0% by S. indicum . Both species were able to penetrate the larvae and complete their life cycles, producing a higher number of infective juveniles (IJs). However, in both species, penetration declined significantly at higher IJ concentrations. Although emamectin benzoate performed better than both EPN species under both pot and field conditions, S. shori showed improved performance in reducing larval populations after the second round of spraying. Considering its effectiveness and environmental safety, the present study highlights the potential of S. shori as a biological control agent against the larval and pupal stages of S. frugiperda. Future studies should evaluate its efficacy against other economically important insect pests and assess its performance under diverse environmental conditions to support its wider field application.

Toward Sustainable Management of Spodoptera frugiperda (Lepidoptera: Noctuidae): A Review on the Role of Endophytic Fungi in Crop Protection

The fall armyworm (FAW), Spodoptera frugiperda, is a highly polyphagous pest that has rapidly expanded across Africa, Asia, and Oceania, threatening food security and agricultural productivity. Reliance on synthetic insecticides for FAW management is increasingly challenged by insecticide resistance, environmental contamination, and adverse effects on non-target organisms and human health. This review synthesizes current knowledge on the potential of endophytic fungi as a sustainable strategy for FAW management. Following a systematic literature search, 59 original research articles published over the past 41 years were evaluated. These studies investigated 44 fungal species across 37 host crops, with Zea mays representing the most extensively studied system. The fungal species most frequently assessed were Beauveria bassiana, Metarhizium anisopliae sensu lato (s.l.), and Epichloe coenophialum. Overall, several fungal species successfully colonized plant tissues and reduced FAW performance through increased larval mortality, delayed development, and reduced feeding. These effects were associated with the production of bioactive secondary metabolites, induction of plant defense responses, and alteration of volatile organic compound emissions. Despite these promising findings, important knowledge gaps remain. Studies assessing effects on non-target organisms and natural enemies are scarce, and field validation remains limited. Research efforts are also geographically biased, with relatively few studies conducted in Africa despite the continent experiencing some of the highest FAW-related losses. Future research should prioritize field evaluations, multitrophic interaction studies, investigations in underrepresented regions, and socio-economic analyses to support farmer adoption. Addressing these gaps will be critical for determining the practical role of endophytic fungi in sustainable FAW management.