Metarhizium Anisopliae Research Articles

Virulence of Native Isolates of Metarhizium anisopliae (Metschnikoff) against Helicoverpa armigera (Lepidoptera: Noctuidae) in Western Uttar Pradesh, India

The chickpea pod borer Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is a destructive pest of chickpeas that is difficult to control using conventional methods. We isolated and evaluated the virulence of five isolates of Metarhizium anisopliae against larvae of H. armigera. All isolates of M. anisopliae, SVPUAT 1, SVPUAT 2, SVPUAT 3, SVPUAT 4, and SVPUAT 5, were most effective against the second instar H. armigera at 2 ×108 conidia/ml. Among all isolates, SVPUAT 1 Accession no. ON183248 had the highest virulence 100% mortality, whereas LT50 and LT90 were 3.16 and 5.16 days.

An updated and validated model for predicting the performance of a biological control agent for the oriental migratory locust.

The oriental migratory locust is a major crop pest across eastern and south-eastern Asia. Metarhizium anisopliae is an effective biopesticide agent used for locust control, but its performance is temperature dependent, and thus can be more variable than chemical pesticide performance. To predict biopesticide performance for the control of the oriental migratory locust, we adapted a previous temperature-dependent model and validated it using field trial data. To increase the applicability of this model, we explored the use of readily available temperature variables, as well as our own satellite-derived canopy temperature variable, to run the model. Compared to collected in situ temperature data, our canopy temperature variable most accurately represented the ambient temperature experienced by the locust. When the biopesticide performance model was run using this canopy temperature and compared to field trials results, the model predictions were more accurate than when the model was run with the other temperature variables. The accuracy of the biopesticide performance model was impacted by vegetation cover, but across the areas most associated with locust oviposition, growth and migration, the model predictions were satisfactorily accurate to guide biopesticide operational use. We validated the model in six provinces in China, representing the three agro-ecological zones largely representative of the oriental migratory locust problem areas in China, Thailand, Cambodia and Vietnam. Whilst further validation work is needed, this model could be used in these countries to assess, at a fine spatial scale, the appropriateness of M. anisopliae for controlling the oriental migratory locust. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The effects of Beauveria bassiana infection on the gene expression profiles of Diaphorina citri adults

The Asian citrus psyllid, Diaphorina citri Kuwayama, is a citrus pest worldwide. This pest transmits the pathogens of Huanglongbing, Candidatus Liberibacter asiaticus (CLas), and has led to huge economic losses. The use of chemical pesticides is the first choice for field pest control, while resistance, resurgence, and residue (3R) problems have received widespread attention. Biological control is an optional and effective method for D. citri management and needs to be developed. In this study, eleven entomopathogenic fungi strains were collected, and their morphologies were recorded. After blasting with the ITS sequences, eight strains were identified as Beauveria bassiana, and three strains were Metarhizium anisopliae. The pathogenicity of these fungi on D. citri adults at 1.0 × 107 conidia/mL was tested, with the LT50 ranging from 4.764 to 8.551. The virulence of B. bassiana strain XM-D1 was further evaluated, and the LC50 was 4.93 × 105 conidia/mL. A total of 155 and 894 differentially expressed genes (DEGs) were identified in the samples after 24 and 48 h of XM-D1 infection, respectively. Further analyses found that the pathways of apoptosis, cholesterol metabolism, fatty acid biosynthesis, and vitamin digestion and absorption could be involved in the response of D. citri adults to 48 h of infection, and DEGs encoding chaperone proteins, cuticle protein 12.5, P450s, and lysozymes may play important roles in immune defense. Our preliminary findings enrich the entomopathogenic fungi repository and shed light on the defense mechanism of D. citri in response to B. bassiana infection at the molecular level.

Hematological and Biochemical Alterations Induced by Two Products from Metarhizium anisopliae after Oral Administration in Male and Female Albino Rats

Hematological and Biochemical Alterations Induced by Two Products from Metarhizium anisopliae after Oral Administration in Male and Female Albino Rats

Entomopathogenic fungi as potential biocontrol agents against Callosobruchus maculatus (F.) and Callosobruchus chinensis L. (Coleoptera: Chrisomelidae: Bruchinae) on stored cowpea seeds

The insecticidal efficacy of four species of Trichoderma genius (T. harzianum, T. citrinoviride, T. viride and T. asperellum) and Metarhizium anisopliae was assessed against Callosobruchus maculatus and C. chinensis on cowpea seeds at concentrations of 2.0 × 106, 2.0 × 107, 2.0 × 108 and 2.0 × 109 conidia/kg. The adult mortality was counted 3 and 7 days after treatment while progeny and seed weight loss were recorded after 45 days. After 7 days, all fungal strains caused significant adult mortality of both insects particularly at 2.0 × 109 spores/kg. Metarhizium anisopliae and T. citrinoviride were the most effective fungi inducing 95 and 93.2% mortalities of C. chinensis at 2.0 × 109 spores/kg, respectively. Callosobruchus chinensis was slightly more susceptible to the fungal strains than C. maculatus. Furthermore, the fungal strains at the highest concentration caused a significant reduction in F1 progeny of both insects. After 45 days, T. harzianum at 2.0 × 109 spores/kg showed the highest protection of cowpea seeds against C. chinensis with weight loss of 6.5%. These findings indicate that the five fungal strains could be implemented in integrated pest management programs of these insects.

Critical stage and key natural mortality factors of Hypothenemus hampei in commercial coffee plantations

AbstractThe coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae), is one of the most important coffee pests, and is present in almost all countries producing this crop, causing annual losses of US$350 million. Natural factors regulate H. hampei populations in coffee crops. Ecological life table analysis is a robust tool that allows the estimation of the mortality caused by these factors. Therefore, the main objective of this study was to determine the critical stage and the key mortality factors affecting H. hampei in the field. Data for constructing life tables were collected over 2 years in six coffee plantations in the regions of Paula Cândido and Viçosa, Minas Gerais State, Brazil. The average mortality of H. hampei was 75.34% ± 5.85%. The mortality at each developmental stage was 24.32% ± 2.83% (eggs), 7.29% ± 1.01% (first instar), 11.58% ± 1.46% (second instar), 9.68% ± 1.10% (third instar), 7.45% ± 1.01% (pupa), and 15.02% ± 1.29% (adult; n = 124). The mortality factors observed and quantified in this study were parasitism by Prorops nasuta (Hymenoptera: Bethylidae), predation by ants (Crematogaster spp., Pheidole spp. and Solenopsis spp.), physiological disorders and fungal infection by Beauveria bassiana and Metarhizium anisopliae. The critical mortality stage of H. hampei was the adult stage. The key factors for mortality of H. hampei adults were predatory ants, followed by B. bassiana and malformations (these insects had deformities in the head, wings, legs, or abdomen). This information is essential to conserve the activities of natural enemies and, thus maintain H. hampei natural mortality factors in coffee plantations, reducing damage to the crops and the need for excessive insecticide interventions.

Pathogenicity of entomopathogenic fungi to eggs, larvae, and adults and their effects on development of Aedes albopictus

Abstract. Ramayanti I, Herlinda S, Muslim A, Hasyim H, Anwar C, Suwandi S, Damiri N, Irsan C, Verawaty M. 2023. Pathogenicity of entomopathogenic fungi to eggs, larvae, and adults and their effects on development of Aedes albopictus. Biodiversitas 24: 4766-4774. No information is available on the effect of fungi on the development of Aedes albopictus and the effectiveness of fungi in killing its eggs, larvae, and adults. The aim of this research was to determine the pathogenicity of entomopathogenic fungi on the eggs, larvae, and adults of Ae. albopictus and to investigate the effects of the fungi on the development of Ae. albopictus. The fungal species identified molecularly were Aedes albopictus, Beauveria bassiana, Metarhizium anisopliae, Penicillium citrinum, and Talaromyces diversus. The results showed that entomopathogenic fungi negatively affected the development of Ae. albopictus and could decrease the eggs laid by adult females and shorten adult longevity. M. anisopliae was the most pathogenic fungal species (mortality rate 100%) for eggs, larvae, pupae, and adults of Ae. albopictus. However, B. bassiana, P. citrinum, and T. diversus were also found pathogenic to them. The effect of eggs treated with entomopathogenic fungi negatively affected the larval, pupal, and adult stages of Ae. albopictus. These findings highlighted that M. anisopliae, B. bassiana, P. citrinum, and T. diversus have insecticidal activity against Ae. albopictus eggs, larvae, pupae, and adults. Therefore, further investigation is needed to develop these fungal species into ovicides, larvicides, and adulticides to control Ae. albopictus.

Insights into sublethal effects of Metarhizium anisopliae on the biotic potentials of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) on maize

BackgroundEntomopathogenic fungi are an important biological agent in integrated pest management, playing a critical role in controlling insect populations. In the present study, the sublethal effects of the entomopathogenic fungus, Metarhizium anisopliae (Ascomycota: Hypocreales), were investigated on the biotic potential of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), which is a major pest of economically important crops.ResultsObtained results revealed that exposure to LC50 concentration of M. anisopliae resulted in a significantly longer larval developmental time (3.25–6.45 days) than the control group (2.42–5.49 days). Similarly, pupal duration was longer in the LC50 treatment (8.24 days) than in the control (6.91 days). Adult longevity was also significantly reduced in the LC50 (9.64 days) and LC30 (10.49 days) treatments compared to the control group (11.7 days). The number of eggs laid by female S. frugiperda exposed to LC50 value of M. anisopliae during the immature stages was significantly lower (464.79 eggs) than that in the control groups (696.93 eggs). Furthermore, all population and age-stage-specific parameters were significantly affected by the sublethal exposure to M. anisopliae at LC30 and LC50 values.ConclusionThese results suggest that sublethal exposure to M. anisopliae negatively impacts the life table parameters of S. frugiperda. However, the use of M. anisopliae at sublethal levels may have potential benefits for integrated pest management strategies seeking to reduce the use of chemicals.

Primary Screening of Microorganisms against Meloidogyne hapla (Chitwood, 1949) under the Conditions of Laboratory and Vegetative Tests on Tomato.

Highly adapted obligate endoparasites of the root system, root-knot nematodes (Meloidogyne spp.), cause great damage to agricultural crops. Our research is aimed at the assessment of nematicidal activity and effectiveness of antagonist fungal and bacterial strains against the most common type of root-knot nematode in the south of Russia. By means of molecular genetic identification, it was found that in the south of Russia, the species Meloidogyne hapla Chitwood, 1949 and Meloidogyne incognita (Kofoid and White, 1919) Chitwood, 1949 cause galls on the roots of open-ground and greenhouse tomato. Screening of microbial agents against second-stage juvenile (J2) M. hapla was carried out in the laboratory. At the end of the experiment, two liquid fungal cultures of Paecilomyces lilacinus BK-6 and Metarhizium anisopliae BK-2 were isolated, the nematicidal activity of which reached 100.0 and 70.2%, and exceeded the values of the biological standard (Nemotafagin-Mikopro) by 38.4% and 8.8%. The highest biological efficacy was noted in the liquid cultures of P. lilacinus BK-6, M. anisopliae BK-2, and Arthrobotrys conoides BK-8 when introduced into the soil before planting tomato. The number of formed galls on the roots was lower in comparison with the control by 81.0%, 75.5%, and 74.4%.

Mycoinsecticides applied in late afternoon to avoid solar UV damage are more efficacious against rice leaf-rolling insect pests than those applied in the morning

Beauveria bassiana ZJU435 (Bb-ZJU435) and Metarhizium anisopliae CQ421 (Ma-CQ421) registered as mycoinsecticides in China were tested for control efficacies against the rice leaf-rolling pests Cnaphalocrocis medialis and Parnara guttata, which migrated to the tillering stage of rice crop in three rice-shrimp rotation paddy fields, where chemical control is prohibited. Either mycoinsecticide was sprayed twice at a recommended rate after 5:00 pm to avoid solar UV avoidance (UVavo) or before 10:00 am to increase solar UV exposure (UVexp). The first spray, although followed by two-week harsh weather, reduced significantly leaf roll densities (damages) in the fungal treatments compared to blank control. The UVavo and UVexp treatments resulted in control efficacies of 63 % and 35 % for Ma-CQ421 and 28 % and 16 % for Bb-ZJU435 on day 14. The second spray was followed by two weeks of weather favorable for fungal action. Consequently, Bb-ZJU435 and Ma-CQ421 showed significantly higher efficacies in their UVavo treatments (60 % and 55 % on day 21; 66 % and 64 % on day 28) than in corresponding UVexp treatments (47 % and 43 % on day 21; 53 % and 50 % on day 28). The UVavo versus UVexp efficacies after the second spray were corrected to ∼95 % versus ∼85 % for Bb-ZJU435, and 75–84 % versus 54–68 % for Ma-CQ421 by verifying whether the leaf rolls were empty (damage-transferred) or occupied by a living or mycosis-killed larva in all treatments. The corrected efficacies of Bb-ZJU435 were significantly higher than those of Ma-CQ421. Conclusively, either mycoinsecticide was more efficacious against the rice leaf rollers when applied in late afternoon to avoid solar UV damage.

Effect of Bio-Agent as Seed Treatment to Check the Initial Infection of Reniform Nematode, Rotylenchulus reniformis on Summer Mungbean (Vigna radiata L.)

Reniform nematode, Rotylenchulus reniformis received greater attention due to its polyphagous nature, cosmopolitan distribution and adaptability to different agro-ecological condition. It causes great losses to pulses including Mungbean (Singh, 2015). Therefore, an experiment was carried out to test the efficacy of botanicals to manage the reniform nematode infecting summer mungbean. Bioagents i.e. Metarhizium anisopliae and Beauveria bassiana were used at 5%, 10% and 15% as seed treatment. Trichoderma viride at 10% was kept as standard check. An untreated check was also maintained to compare the experimental findings. The experiment was conducted in completely randomized design with five replications. Results revealed that Metarhizium anisopliae at 15 % w/w as seed treatment significantly improve the plant growth parameters (44.81–77.21%) of summer mungbean followed by Beauveria bassiana at 15% (38.44-70.88%) and Metarhizium anisopliae at 10% (34.13–62.50%) as compared to untreated check. These treatments reduced the infestation of reniform nematode, R. reniformis on mungbean to the tune of 36.04-47.43%.

Transcriptomic Analysis of Metarhizium anisopliae-Induced Immune-Related Long Non-Coding RNAs in Polymorphic Worker Castes of Solenopsis invicta.

Long non-coding RNAs (lncRNAs) represent a class of RNA molecules that do not encode proteins. Generally studied for their regulatory potential in model insects, relatively little is known about their immunoregulatory functions in different castes of eusocial insects, including Solenopsis invicta, a notoriously invasive insect pest. In the current study, we used Metarhizium anisopliae, an entomopathogenic fungus, to infect the polymorphic worker castes (Major and Minor Workers) and subjected them to RNA sequencing at different intervals (6, 24, and 48 h post-infection (hpi)). Comprehensive bioinformatic analysis identified 5719 (1869 known and 3850 novel) lncRNAs in all libraries. Genomic characteristics analysis showed that S. invicta lncRNAs exhibited structural similarities with lncRNAs from other eusocial insects, including lower exon numbers, shorter intron and exon lengths, and a lower expression profile. A comparison of lncRNAs in major and minor worker ants revealed that several lncRNAs were exclusively expressed in one worker caste and remained absent in the other. LncRNAs such as MSTRG.12029.1, XR_005575440.1 (6 h), MSTRG.16728.1, XR_005575440.1 (24 h), MSTRG.20263.41, and MSTRG.11994.5 (48 h) were only present in major worker ants, while lncRNAs such as MSTRG.8896.1, XR_005574239.1 (6 h), MSTRG.20289.8, XR_005575051.1 (24 h), MSTRG.20289.8, and MSTRG.6682.1 (48 h) were only detected in minor workers. Additionally, we performed real-time quantitative PCR and experimentally validated these findings. Functional annotation of cis-acting lncRNAs in major worker ants showed that lncRNAs targeted genes such as serine protease, trypsin, melanization protease-1, spaetzle-3, etc. In contrast, apoptosis and autophagy-related genes were identified as targets of lncRNAs in minor ants. Lastly, we identified several lncRNAs as precursors of microRNAs (miRNAs), such as miR-8, miR-14, miR-210, miR-6038, etc., indicating a regulatory relationship between lncRNAs, miRNAs, and mRNAs in antifungal immunity. These findings will serve as a genetic resource for lncRNAs in polymorphic eusocial ants and provide a theoretical basis for exploring the function of lncRNAs from a unique and novel perspective.

Caste composition contributes to improve the social immunity in a nasute termite species exposed to entomopathogenic fungus

Abstract The evolution of a reproductively altruistic caste contributed to the success of eusociality through the division of labour. In termites, the proportion of soldiers in the colonies increased throughout the group's evolution. In Nasutitermitinae, soldiers have a crucial role in defence, resource selection and foraging. However, the role of soldiers and workers in colony immunity is still poorly understood. Here, we evaluated the role of mixed caste groups in the social immunity of Nasutitermes corniger (Termitidae: Nasutitermitinae) exposed to the entomopathogenic fungi Metarhizium anisopliae (Metsch.). We tested the hypothesis that the presence of workers and soldiers optimizes defence against pathogens, and this defence is increased when the soldier ratio is closer to what naturally occurs in colonies. Our results showed that mixed caste groups of N. corniger exposed to M. anisopliae survive longer compared to groups with only one caste. In addition, termite groups that died from fungi were less likely to show fungal infection in mixed caste groups. The behavioural observations suggest that in the natural proportion of soldiers, allogrooming and trophallaxis play a crucial role in the control of disease and its death hazard in termites. Soldiers may play an important role in colony immunity, being able to start the alarm signal indicating the threat of pathogens. Our results show that the presence of the two castes promotes possible mechanisms for socially mediated immunity. This study may help in the understanding of the function of the soldiers and workers and the significance of pathogens in termite eusocial evolution.

Development of a novel pilot-scale tray bioreactor for solid-state fermentation aiming at process intensification

Solid-State Fermentation (SSF) processes have high contamination and low productivity rates, since it involves batch processes with multiple manual stages. In order to reduce handling in SSF processes, this research developed a pilot-scale tray bioreactor that enables process intensification by combining upstream operations and fermentation in a single equipment. Thus, a novel tray bioreactor was developed with an atomization system of spore suspension, nutrient solution, and cooling water above the fermentative medium. It also incorporates a sterilization system using steam. In order to validate the bioreactor, two case studies were conducted. In the first case study, the fungus Metarhizium anisopliae was cultivated on three types of agro-industrial residues. The conidia/mL obtained using the mixture of wheat bran and broken rice was (16.7±0.46)×108, which is statistically higher (α=0.05) than the fungus production of (8.59±1.60)×108 cultivated on the control (Type I Rice). In the second case study, lipases from M. anisopliae were produced on agro-industrial residues. The enzymatic activity average was 5.64±0.45U/mL based on 36 fermentations. The results have shown that the new tray bioreactor can produce the fungus and lipases in greater quantities than other systems reported in literature, while reducing handling, energy, costs, and process time.

Effect of three fungi species application and concentration on production and pest attack on shallot (Allium ascalonicum L.)

This study aims to determine the influence of three types of beneficial fungi with various concentration of application on shallot production and pest attacks. This research was carried out at the Plant Disease Laboratory and Teaching Farm, Faculty of Agriculture, Hasanuddin University, from September to November 2022. This research was arranged in a split plot design. The main plots are three types of fungi, namely Trichoderma asperellum, Beauveria bassiana and Metarhizium anisopliae, while the plot consists of concentration consisting of 0, 7, and 14 g/L. Results showed that there was no interaction that had an influence on production, bulb moisture content, production per hectare and the percentage of Spodoptera exigua attacks. The highest production per hectare was recorded in the Beauveria bassiana treatment of 15.97 tons. The application of the fungus at a concentration of 14 g/L producing the lowest weight loss of bulb 3.17%, production per hectare of 17.27 t and the lowest percentage of Spodoptera exigua attacks was 6.19%.

Evaluation of the application of rice husk biochar and various types of microbes on physiological and characteristics of shallot bulbs (Allium ascalonicum L.)

Shallot is a popular and widely developed horticultural crop in Indonesia. This study aims to evaluate the application of rice husk biochar and various types of microbes on the physiological and bulbs characteristics of shallot (Allium ascalonicum L.). The research design used a split plot design. The main plot was rice husk biochar with three levels, namely control 0 t ha−1, 2 t ha−1, and 4 t ha−1. As subplots, there were three types of microbes namely without microbes/control, Trichoderma asperellum, Beauveria bassiana, and Metarhizium anisopliae. The results optained that there was an interaction between the of rice husk biochar 4 t ha−1 with the Trichoderma asperellum which gave the best results for the chlorophyll index (19.70). The application of various types of microbes namely in the of Trichoderma asperellum gave the best results on bulb height (2.75 cm) and the number of bulbs per plant (1.61).

Enhancing Red Ginger Plant Growth through Eco-Friendly Pest Management: Synergistic Effects of Metarhizium anisopliae and Imidacloprid

This study explores the potential of a more environmentally friendly pest management approach for enhancing the vegetative growth of red ginger plants (Zingiber officinale Rosc.) by mitigating the damage caused by Lepidiota stigma (white grub) larvae. The study was conducted at the Experimental Garden of the Faculty of Agriculture, UPN “Veteran” Yogyakarta from April to August 2022, utilizing a factorial Completely Randomized Design. The application of the entomopathogenic fungus Metarhizium anisopliae at varying doses (0 g, 10 g, 20 g, and 30 g per 3 kg of planting media) and the systemic insecticide Imidacloprid (either absent or at a dose of 0.02 g per 3 kg of planting media) were the primary factors studied. Each treatment combination, executed on ten plants each infested with one larvae, was repeated thrice. The findings demonstrate that a combined application of M. anisopliae and Imidacloprid could significantly reduce the intensity of white grub damage to red ginger plants and improve their vegetative growth. Notably, a dose of M. anisopliae of 20 g per 3 kg of planting media maximized the plant height, leaf number, and tiller count. The findings highlight the potential of integrating biological and chemical controls for sustainable pest management and crop yield improvement, with broad implications for other similar agricultural contexts.

Effectiveness test the entomopathogenic fungus Metarhizium anisopliae (Metch) at various concentrations against Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae) larvae in the laboratory

Spodoptera frugiperda is one of the most important major pests of maize in the world. Armyworms are polyphagous, the main target is corn, pests can move to other hosts if there is no primary host so that these pests can survive and maintain their populations throughout the year. S.frugiperda is also considered a serious insect pest because it reproduces in several generations per year and adults can fly up to 100 km per night, giving it the potential to spread widely in a short time. This study aim to determine the effectiveness of the entomopathogenic fungus Metarhizium anisopliae (match) at various concentrations against S. Frugiperda. This study was conducted in laboratory conditions, using a completely randomized design using four treatments and five replications. Each replicates used 20 test larvae. the treatments were: control, concentration of M. anisopliae 107, M. anisopliae 108, and of M. anisopliae 109. The larvae used as test larvae were instar 2 larvae, and observations were made every day to see the mortality of the test insects and record the symptoms that appeared in larvae after the application of M. anisopliae. The results showed that there was an effect of mortality on the test insects seen in treatment 108 showing the highest treatment of 9.15 days after application compared to all treatments. at 14 days post-application. The results of this study indicate the need for proper development for the purpose of effective pest control in crop cultivat.

Akanthomyces dipterigenus acts as a potential biocontrol agent by causing mortality and inhibiting population growth of Bemisia tabaci

Bemisia tabaci is a worldwide pest, and has developed severe resistance to many insecticide. Therefore, it is great significance to find new substitute for chemical insecticide to control B. tabaci. In this study, selected efficient strains by comparing the virulence of Akanthomyces dipterigenus, Cordyceps javanica, Purpureocillium lilacinum, Penicillium camemberti, Metarhizium anisopliae, and Beauveria bassiana against 2nd-instar nymphs of B. tabaci and bioassays were conducted on various developmental stages of B. tabaci using highly pathogenic strain. Additionally, the effects of medium lethal concentration of high-efficiency strains on the biological parameters of B. tabaci were also studied. The bioassay showed that six entomopathogenic fungi have significant effects on the 2nd-instar nymphs of B. tabaci, the median lethal concentration (LC50) of A. dipterigenus against 2nd-instar nymphs of B. tabaci was only 6.54 × 103 (3.35 × 103–1.13 × 104) conidia mL−1, which was lower than that of the other five fungi, and the median lethal time (LT50) was the shortest. In addition, A. dipterigenus also had lethal effects on eggs, nymphs and adults of B. tabaci, among which the mortality rate of 2nd-instar nymphs was the highest. The fungal treatment affected the population parameters of B. tabaci, R0, r, and λ were significantly reduced, T was significantly prolonged, and had higher preadult mortality and shorter adult longevity, but had no significant effect on the total fecundity. These findings highlight the potential of using A. dipterigenus as a sustainable and eco-friendly alternative to chemical insecticides for controlling B. tabaci populations in agricultural settings.

Efficacy of entomo-pathogenic fungus and botanical pesticides against mustard aphid (Lipaphis erysimi Kalt.) at field condition Rupandehi Nepal

Mustard aphid is the most concerning pest of rapeseed in warm and humid areas of Nepal because of its widespread prevalence and increasing severity. There is increasing use of chemicals, as the only resort, to manage this pest. The experiment was carried out to evaluate the effectiveness of different bio-friendly management techniques against Mustard aphid, at the Institute of Agriculture and Animal Science, Paklihawa campus. Treatments like “Jholmal” (250 ml/L), Beauveria bassiana (4gm/L) Abamectin @ 1 ml/L of water, Metarhizium anisopliae (2 gm/L), Verticillium lecanii 2% A.S (5 ml/L) and Neem oil (5 ml/L) were used at post-infestation condition. Results revealed that the overall performance of Abamectin was found to be remarkably effective as compared to others. However, the performance of “Jholmal” and Neem was also found similar for both adult and nymph management. Also, the yield and yield attributing characters in “Jholmal”, Neem, and Abamectin treated plots were similar. However, Abamectin was not found to be convincing considering its impact on natural enemies and thus “Jholmal” and Neem are suggested from the experimental results for the management of mustard aphids at the farmer's level.