Maruca Vitrata Research Articles

A chromosome-level genome assembly of the soybean pod borer: insights into larval transcriptional response to transgenic soybean expressing the pesticidal Cry1Ac protein

BackgroundGenetically modified (GM) crop plants with transgenic expression of Bacillus thuringiensis (Bt) pesticidal proteins are used to manage feeding damage by pest insects. The durability of this technology is threatened by the selection for resistance in pest populations. The molecular mechanism(s) involved in insect physiological response or evolution of resistance to Bt is not fully understood.ResultsTo investigate the response of a susceptible target insect to Bt, the soybean pod borer, Leguminivora glycinivorella (Lepidoptera: Tortricidae), was exposed to soybean, Glycine max, expressing Cry1Ac pesticidal protein or the non-transgenic parental cultivar. Assessment of larval changes in gene expression was facilitated by a third-generation sequenced and scaffolded chromosome-level assembly of the L. glycinivorella genome (657.4 Mb; 27 autosomes + Z chromosome), and subsequent structural annotation of 18,197 RefSeq gene models encoding 23,735 putative mRNA transcripts. Exposure of L. glycinivorella larvae to transgenic Cry1Ac G. max resulted in prediction of significant differential gene expression for 204 gene models (64 up- and 140 down-regulated) and differential splicing among isoforms for 10 genes compared to unexposed cohorts. Differentially expressed genes (DEGs) included putative peritrophic membrane constituents, orthologs of Bt receptor-encoding genes previously linked or associated with Bt resistance, and those involved in stress responses. Putative functional Gene Ontology (GO) annotations assigned to DEGs were significantly enriched for 36 categories at GO level 2, respectively. Most significantly enriched cellular component (CC), biological process (BP), and molecular function (MF) categories corresponded to vacuolar and microbody, transport and metabolic processes, and binding and reductase activities. The DEGs in enriched GO categories were biased for those that were down-regulated (≥ 0.783), with only MF categories GTPase and iron binding activities were bias for up-regulation genes.ConclusionsThis study provides insights into pathways and processes involved larval response to Bt intoxication, which may inform future unbiased investigations into mechanisms of resistance that show no evidence of alteration in midgut receptors.

Population dynamics of pod pest complex of pigeonpea

A field experiment was conducted at Main Agricultural Research Station, University of Agricultural Sciences, Dharwad, to study the population dynamics of pod pest complex of pigeonpea. The observations were recorded at fortnightly intervals starting from flower initiation stage upto the harvest of the crop. The peak activity of gram pod borer (3.63 larvae/plant), spotted pod borer (3.63 larvae/plant) and pod bugs (4.62 bugs/plant)was observed during 50th Standard Meteorological Week. The pod damage caused by Helicoverpa armigera (25.02%) and Maruca vitrata (16.77%) was also highest during 50th Standard Meteorological Week. The maximum pod damage by plume moth (12.02%) was noticed at 52nd Standard Meteorological Week. The 52nd Standard Meteorological Week witnessed highest pod fly population (10.80 maggots / 10 pods), per cent pod damage (27.75%), and per cent seed damage (17.51%).The correlation studies of incidence of pod pest to prevalent weather parameters revealed that, gram pod borer and the spotted pod borer were more prevalent as the minimum temperature rose, but pod fly and pod bugs population increased negatively. There was a negative correlation between the population of all pod pest, including gram pod borer, spotted pod borer, pod bugs and pod fly with maximum relative humidity, minimum relative humidity and rainfall.

Assessment of Bioefficacy of Chilli Pepper Capsicum frutescens (L.) and its Intercropping on the Performance and Insect Pests Management of Bambara Groundnut (Vigna subterranea L.)

A study was conducted at the Yaba College of Technology Instructional and Research Farm in 2022 and 2023 wet and dry seasons to determine the bio-efficacy of chilli pepper, (Capsicum frutescens (L.)) and its intercropping on the growth, yield and insect pest management of Bambara groundnut (Vigna subterranea (L.)). The experiment was laid out in a 3×4 factorial experiment in Randomized Complete Block Design with 3 treatments (chilli pepper extract at 200l/ha, 250l/ha, and local control) at 3 replications in alternate intercropping, strip cropping, border cropping, and sole cropping arrangement. The chilli pepper aqueous extract at 200 l/ha and 250 l/ha sprayed on the Bambara groundnut plants were sprayed as scheduled from 10 am to 12 noon with the view of protecting it with aqueous extract of chilli pepper on 12 plots of 60 ridges. Data were collected on growth parameters of Bambara groundnut at 2, 4, and 6 weeks after planting, pest population, assessment of thrips and legume pod borer, assessment of both nymph and adult of legume pod borer and pod sucking bugs, pod density, pod damage, grain yield, yield loss and assessment of phytotoxicity signs using Analysis of Variance. Results showed that 250 l/ha aqueous extract treated plots reduced the number of insect pests including thrips (4.67±1.09), legume pod borer (1.76±0.35), legume pod borer nymph (1.08±0.10) adults of pod borers (1.18±0.11) and pod sucking bugs adult (3.33±1.09) in intercropping situation, followed by 200 l/ha respectively as compared to untreated plots (2.69±0.12). There was a significant difference (p < 0.05) between the treated plots (9.08±0.62) and untreated plots (12.44±0.71) in terms of pod damage as well as increased grain yields (343.73±4.71) when compared to the untreated control (322.12±43). However, 250 l/ha causes higher phytotoxicity damage than 200 l/ha although it controlled pest population better than 200 l/ha. Alternate cropping proved to be superior to other cropping system with respect to grain yield (36.78±12.99), reduction in pest infestation (6.33±1.23) and reduction in yield loss (299.58±9.41) when compared to sole cropping of Bambara groundnut with respect to grain yield (100.24±12.99), reduction in pest infestation (15.33±1.23) and reduction in yield loss (395.27±9.41). The bio-pesticidal effect of chilli pepper on Bambara groundnut insects may be due to the presence of active ingredients present in chilli pepper including glycosides, tannin, terpenoides, flavonoids, saponin, reducing sugar, steroids, and resins. This result indicates the potential of using plant extract with insecticidal attributes for the protection of Bambara groundnut in low input agriculture practiced by limited resource farmers in developing countries.

Enhanced baculoviral virulence by suppressing the degradation of an insect immune resolvin, epoxyoctadecamonoenoic acid, in three lepidopteran insects

Epoxyoctadecamonoenoic acids (EpOMEs) are produced from linoleic acid by a cytochrome P450 monooxygenase (CYP) and play a crucial role in terminating excessive and unnecessary immune responses during the late infection stage in insects. This suggests that an increase in the EpOME level may enhance the virulence of insect pathogens against pests. This study tested this hypothesis using a specific inhibitor against soluble epoxide hydrolase (sEH) to degrade EpOMEs, which leads to elevated endogenous EpOME levels. A baculovirus, Autographa californica multiple nucleopolyhedrovirus (AcMNPV), was used to infect three different lepidopteran insects (Spodoptera exigua, Maruca vitrata, and Plutella xylostella) by oral feeding or hemocoelic injection treatments. Within one hour, the viral infection induced the expression of three different phospholipase A2 (PLA2) genes and, after 12 h, up-regulated the expressions of CYP and sEH genes in Spodopera exigua. As expected, AcMNPV virulence was suppressed by the addition of arachidonic acid (a catalytic product of PLA2) but was enhanced by the addition of either of the EpOME regioisomers. In addition, treatment with a specific sEH inhibitor (AUDA) increased AcMNPV virulence against three different lepidopteran insects, presumably by increasing endogenous EpOME levels. This enhanced effect of EpOMEs on virulence was further supported by specific RNA interference (RNAi), in which RNAi specific to CYP expression decreased AcMNPV virulence while a specific RNAi against sEH expression significantly enhanced virulence. In response to AcMNPV infection, TUNEL assay results showed that S. exigua larvae exhibited apoptosis in the midgut, fat body, and epidermis. Inhibition of apoptosis by a pan-caspase inhibitor, Z-VAD-FMK, significantly increased virulence. Similarly, the addition of AUDA to the viral treatment suppressed the gene expression of five inducible caspases and cytochrome C to suppress apoptosis, which led to a significant increase in the tissue viral titers. These results indicate that EpOMEs play a role in terminating excessive and unnecessary immune responses against viral infection during the late stage by down-regulating antiviral apoptosis in lepidopteran insects.

Maruca vitrata (Fabricius) (Lepidoptera: Crambidae): comparative infestation and seasonal population fluctuations on different pigeonpea genotypes in Punjab, India

Maruca vitrata (Fabricius) (Lepidoptera: Crambidae): comparative infestation and seasonal population fluctuations on different pigeonpea genotypes in Punjab, India

Bio-efficacy of certain new insecticides against pod borer complex in pigeonpea (Cajanus cajan L.)

A study on evaluation of certain new insecticides against pod borer complex in pigeonpea was conducted at Regional Agricultural Research Station, Warangal for three consecutive years from Kharif 2019-20 to Kharif 2021 22 in medium maturity pigeonpea cultivar ‘Rudreswara’ (WRG-65). Seven treatments including untreated control were evaluated for their relative efficacy towards suppression of pod borer larval population and reduction of percent pod damage. The insecticide treatments along with untreated control were applied two times during the crop season viz., 50% flowering and pod formation stage. The results revealed that chlorantraniliprole 18.5 SC @ 0.3 ml/L followed by emamectin benzoate 5 SG proved significantly superior against gram pod borer (Helicoverpa armigera) and spotted pod borer (Maruca vitrata) with highest mean percent larval reduction and cumulative least percent pod damage (10.8 and 14.7%, respectively) over control. Further, chlorantraniliprole 18.5 SC followed by emamectin benzoate 5 SG @ 0.4 g/l recorded higher grain yields and best ICBR ratio (1:4.6; 1:4.5). Thus, the effective chemicals observed in the study could be used as basis for selection of label recommended insecticides for successful management of pod borers in pigeonpea.

Screening of Different Genotypes/Varieties of Greengram against Spotted Pod Borer, Maruca vitrata (Fabricius)

An experiment was carried out to evaluate the different genotypes/varieties of greengram against spotted pod borer, Maruca vitrata during kharif 2021 at Agronomy Farm, Anand Agricultural University, Anand. Total 20 genotypes/varieties were used and experiment was conducted in randomized block design with two replications. Among the twenty genotypes/varieties screened for their resistance to spotted pod borer, none of the genotypes/varieties was found to be highly resistant. Based on larval population, four genotypes/variety viz., VSGG 9, VMK 19-03, VMK 18-01 and Meha were categorized as resistant to spotted pod borer. While VSGG 2, GM 6, VSGG 8 and VSGG 4 were found susceptible. None of the genotypes/varieties was categorized as highly susceptible. The grain yield of different genotypes differed significantly and ranged from 757 kg/ha in the genotype VSGG 9 to 438 kg/ha in VSGG 4.

Overexpression of cry1c* Enhances Resistance against to Soybean Pod Borer (Leguminivora glycinivorella) in Soybean.

Soybean [Glycine max (L.) Merr.], an essential staple food and oil crop worldwide, boasts abundant vegetable proteins and fats beneficial for both human and animal consumption. However, the soybean pod borer (Leguminivora glycinivorella) (SPB) stands as the most destructive soybean insect pest in northeast China and other northeastern Asian regions, leading to significant annual losses in soybean yield and economic burden. Therefore, this study aims to investigate the introduction of a previously tested codon-optimized cry1c gene, cry1c*, into the soybean genome and assess its effect on the SPB infestation by generating and characterizing stable transgenic soybeans overexpressing cry1c*. The transgenic soybean lines that constitutively overexpressed cry1c* exhibited a significant reduction in the percentage of damaged seeds, reaching as low as 5% in plants under field conditions. Additionally, feeding transgenic leaves to the larvae of S. exigua, S. litura, and M. separta resulted in inhibited larval growth, decreased larval body weight, and lower survival rates compared to larvae fed on wild-type leaves. These findings showed that the transgenic lines maintained their resistance to SPB and other lepidopteran pests, especially the transgenic line KC1. Southern blotting and genome-wide resequencing analysis revealed that T-DNA integration occurred as a single copy between loci 50,868,122 and 50,868,123 of chromosome 10 in the transgenic line KC1. Therefore, the transgenic line KC1, overexpressing high levels of cry1c* in leaves and seeds, holds strong potential for commercial use in the integrated management of SPB and other lepidopteran pests.

Estimation of Yield Losses Caused by Insect Pests on Pigeon Pea (Cajanus cajan (L.) Millsp.)

Field experiment was carried out to estimate the yield losses in pigeon pea crop due to insect pests during kharif 2018-19, 2019-20 and 2020-21 at College of Agriculture, Navsari Agricultural University, Bharuch (Gujarat). Results revealed that avoidable yield loss due to insect pests in pigeon pea was recorded up to 38.48% when no plant protection measures are taken. Amongst different insect pests, the maximum damage was recorded due to pod borer, Helicoverpa armigera (34.90%) followed by pod sucking bugs, Clavigralla gibbosa (29.75%) and pod fly, Melanogromyza obtusa (23.64%). Pod damage due to spotted pod borer, Maruca vitrata and tur plume moth, Exelastis atomosa was recorded up to 14.09% and 5.60%, respectively.

IGKM 05-18-2: identified as high yielding and multiple disease resistance rabi mungbean genotype for Chhattisgarh state

To enhance the yield potential in the rabi season, a high yielding and multiple disease resistant mungbean genotype, IGKM 05-18-2 has been developed through pedigree method from cross between Pairy Mung x Pusa Vishal at IGKV, Raipur, Chhattisgarh. The entry was tested in multilocation trial (12 locations) for three years (2017-18 to 2019-20) followed by testing in All India Coordinated Research Project on MULLaRP for a period of two years (2019-20 and 2020-21). It was also screened for various pests and diseases under pathological trials of AICRIP. Based on three years data (2017-18 to 2019-20) in state multilocation trials, during Rabi season, the entry IGKM 05-18-2 (902.40 Kg ha-1) had shown 8.29 % yield increase over the best check i.e. Pairy Mung (833.27 Kg ha-1). Likewise, under All India Coordinated Research Project (AICRP on MULLaRP) this entry shown the 6.46 % yield advantage over the best check VBN 4 based on the mean performance in IVT and AVT-1 trials. In addition to the yield advantages, it shown multiple resistances to MYMV, Cercospora leaf spot, Powdery mildew and root rot in co-ordinated trials whereas, it was found resistant against PM, MYMV and Alternaria leaf spot at station trial. The entry IGKM 05-18-2 showed moderate insect pest infestation and was considered as promising entry. The entry IGKM 05-18-2 was found with moderate insect pest (thrips, whiteflies and maruca pod borer) infestation and considered as promising entry and the higher seed yield was recorded than Local check LGG 450. The data of the tested entry revealed the mungbean genotype, IGKM 05-18-2 is found to have high yield potential, multiple disease resistant and most suitable for cultivation in rabi season of the state. This improved line with enhanced resistance for multiple diseases can also be further used as a resistant donor for transfer disease resistance genes in other elite cultivars.

Effect of Insecticides on Natural Enemies in Groundnut

The most significant effect of inadvertent application of pesticides has been the eradication of natural enemies. It is necessary to assess the insecticidal qualities, mammalian toxicity, and safety to natural enemies before incorporating in IPM. This study evaluates the impact of some insecticides on natural enemies of groundnut defoliators viz., Spodoptera litura (F), Helicoverpa armigera (Hübner), Thysanoplusia orichalcea (F), Aproaerema modicella (Deventer) and Maruca vitrata (Geyer). The results revealed maximum occurrence of coccinellid and spider predators in untreated control, and all the insecticides were comparable as regards their effect.

Report of <i>Maruca vitrata</i> (F) Nucleopolyhedrovirus

This study explores the potential of nucleopolyhedroviruses (NPVs) as a sustainable solution for managing legume pod borer Maruca vitrata (F). Distinctive signs of viral infection, such as suspended deceased larvae on cowpea leaves, and virus spread have been observed. Microscopic examination reveals characteristic polyhedral inclusion bodies (PIBs), confirming MaviNPV as the causative agent. Symptoms, including decreased activity and mortality in younger larvae, larval-pupal intermediates and deformed pupae have been observed. Reproductive disruption is evident through the absence of an egg mass and discharge of fluid from emerged adults. Bioassay results highlight age-dependent susceptibility, with higher mortality in early instars.

Using bioproducts for soybean protection against the soybean pod borer (Leguminivora glycinivorella Mats.) under the conditions of the steppe zone of Primorsky kray

This paper presents the results of a study on bioproducts BioKill, EC, and Proclaim, WG, against the soybean pod borer (Leguminivora glycinivorella Mats.), which damages soybean pods in the agroecosystems of Primorsky kray. This species is one of the main soybean pests in the Russian Far Eastern federal district. The research was conducted on late soybean variety Briz in the conditions of the steppe zone of Primorsky kray – in the soybeans fields of FSBSI “FSC of Agricultural Biotechnology of the Far East named after A.K. Chaiki”. The plan of the experiment included the use of bioinsecticides BioKill, EC, and Proclaim, WG, for treating plants either during the growing period (two times) or in combination with seed-applied insecticide Imidor Pro, SC. Our research goal was to evaluate the biological and economic efficacy of the bioproducts against Leguminivora glycinivorella Mats. It was established that applying the bioinsecticides decreased the degree of the damage caused by the soybean pod borer (larvae) to soybean pods and seeds and positively affected the productivity of soybean plants. Bioproduct BioKill, EC, had the highest biological efficacy. The protective properties of bioinsecticide Proclaim, WG, were observed to be weaker. The research results demonstrated that bioproducts BioKill, EC, and Proclaim, WG, were effective against the soybean pod borer Leguminivora glycinivorella Mats. and could be used as soybean protection products in the agroecosystems of the Russian Far East.

Methylglyoxal metabolism is altered during defence response in pigeonpea (Cajanus cajan (L.) Millsp.) against the spotted pod borer (Maruca vitrata).

Pigeonpea (Cajanus cajan ) production can be affected by the spotted pod borer (Maruca vitrata ). Here, we identified biochemical changes in plant parts of pigeonpea after M. vitrata infestation. Two pigeonpea genotypes (AL 1747, moderately resistant; and MN 1, susceptible) were compared for glyoxalase and non-glyoxalase enzyme systems responsible for methylglyoxal (MG) detoxification, γ-glutamylcysteine synthetase (γ-GCS), glutathione-S-transferase (GST) and glutathione content in leaves, flowers and pods under control and insect-infested conditions. MN 1 had major damage due to M. vitrata infestation compared to AL 1747. Lower accumulation of MG in AL 1747 was due to higher activities of enzymes of GSH-dependent (glyoxylase I, glyoxylase II), GSH-independent (glyoxalase III) pathway, and enzyme of non-glyoxalase pathway (methylglyoxal reductase, MGR), which convert MG to lactate. Decreased glyoxylase enzymes and MGR activities in MN 1 resulted in higher accumulation of MG. Higher lactate dehydrogenase (LDH) activity in AL 1747 indicates utilisation of MG detoxification pathway. Higher glutathione content in AL 1747 genotype might be responsible for efficient working of MG detoxification pathway under insect infestation. Higher activity of γ-GCS in AL 1747 maintains the glutathione pool, necessary for the functioning of glyoxylase pathway to carry out the detoxification of MG. Higher activities of GST and GPX in AL 1747 might be responsible for detoxification of toxic products that accumulates following insect infestation, and elevated activities of glyoxylase and non-glyoxylase enzyme systems in AL 1747 after infestation might be responsible for reducing reactive cabanoyl stress. Our investigation will help the future development of resistant cultivars.

Evaluation of newer insecticides against spotted pod borer and its pod damage in summer green gram

Evaluation of newer insecticides against spotted pod borer and its pod damage in summer green gram

Evaluation of Certain Biopesticides against Helicoverpa armigera and Maruca vitrata in Pigeonpea

Evaluation of Certain Biopesticides against Helicoverpa armigera and Maruca vitrata in Pigeonpea

Effect of selected insecticides and biopesticides against pod borer, Maruca vitrata of cowpea

Effect of selected insecticides and biopesticides against pod borer, Maruca vitrata of cowpea

Preliminary Evaluation of Onion Bulb and Tobacco Leaf Extracts for Insect Control and Yield of Cowpea in the Southern Guinea Savanna of Nigeria

The study evaluated the effects of onion (Allium cepa) bulb and tobacco (Nicotiana tabacum) leaf extract on the insect pests and yield components of cowpea. The extracts were tested on number of the flower thrips, Megalurothrips sjostedti Trybom, the pod-sucking bug, Clavigralla tomentosicollis Stal, the pod borer, Maruca vitrata (F.) and cowpea aphid, Aphis craccivora Koch. Also evaluated were the dry seed weight, 100-seed weight, pod length, number of pods per plant, number of seeds per pod, pod load, pod damage and pod evaluation index. Field experiment was conducted in the Faculty of Agriculture, University of Ilorin, Ilorin, Nigeria. Plots were laid out in a randomized complete block design with three replications. Treatments included 10% (w/v) of each of onion bulb and tobacco leaf extracts, synthetic insecticide (Cypermethrin 1 L/ha) and untreated control. Results revealed that cowpea treated with the plant extracts had significantly (p<0.05) lower insect pest population than plants in untreated plots which suffered greater insect pest attack. However, plots treated with Cypermethrin produced significantly higher number of seeds per pod than other treatments. Nevertheless, tobacco leaf extract produced significantly (p<0.05) heavier 100-seed weight than other treatments including the control. It could be concluded that the plant extracts had potential to replace the synthetic insecticide for control of insect pests of cowpea, thus ensuring environmental safety.

Protection of soybean plants from phytophages under conditions of the Primorsky Territory

The effectiveness of pre-sowing treatment of soybean seeds and application of biorational insecticides in reducing the number of major pests of soybean in the conditions of the Primorsky Territory have been studied. The results of using insecticides and biopreparations to regulate the number of dominant pests of soybean have been presented. The studies were conducted in 2020 and 2021. The efficiency of insecticidal protectants Imidor Pro, SC (2 l/t) and Tabu, WSC (1.0 l/t), bioinsecticides Fitoverm, EC (0, 16 l/ha), Proclaim, WSG (0.3 kg/ha), Batsikol, L (15 l/ha), Biosleep BW, L (2 l/ha), Biosleep BT, P (2 kg/ha) against two-striped leaf beetle (Medythia nigrobilineatus Motsch.) and soybean pod borer (Leguminivora glycinivorella Mats.) were studied. Pre-sowing seed treatment with insecticides Imidor Pro and Tabu reduced damage of soybean plants in the sprouting phase by Medythia nigrobilineatus beetles compared to the control by 94.0–98.2%. Seed dressing with imidacloprid-based preparations provided effective protection of crops against the pest in the sprouting – branching phase. Biorational insecticides based on avermectin C and Bacillus thuringiensis showed high biological efficacy (71.1–98.8%) on the 5–10th day after treatment against the two-striped leaf beetle. Soybean seed damage when bioinsecticides were used against Leguminivora glycinivorella was 1.9–3.0% compared to 5.6% in the control. The conducted studies testify to the prospect of using the preparations of biological origin to control the number of dominant pests in soybean crops.

Influence of Different Planting Dates on the Occurrence of Key Pests Affecting Blackgram in the Lower Gangetic Alluvial Plain of West Bengal

A field oriented experiment was executed over two consecutive summer months in 2019 and 2020 to study the influence of sowing dates of blackgram or urdbean (Vigna mungo L. Hepper) on the population fluctuation of its major pests viz., flower infesting thrips (Megalurothrips sp.) and spotted pod borer or legume pod borer (Maruca vitrata Fabr.). The blackgram variety PU 31 was sown on three different dates, with ten days apart specifically, on the 14th of March, 24th of March and 3rd of April each year, representing early, medium and late sown crops. The experiment recorded fewer incidences of flower thrips in late-sown crop (population of 2.56 per 10 flowers in first year and 1.22 in second year) than early crop (4.71 and 2.42 in those years, respectively), while higher incidences of pod borer was recorded in late-sown crop (larval population of 2.49 plant-1 in first year and 2.58 in second year) than early crop (0.69 and 0.42 in those years, respectively). Given that early and late-sown crops attract more thrips and pod borers, respectively, it may be recommended to sow black gram during the last week of March, especially in the lower Gangetic plains of West Bengal.