Litura Larvae Research Articles

Field resistance of Spodoptera litura (Fab.) to conventional insecticides in India

The present study was carried out to evaluate conventional insecticide resistance in populations of Spodoptera litura (Fab.) from seven different soybean-growing districts (Dharwad. Belgaum, Pune, Parbani, Adilabad, Hyderabad and Indore) of India. Experimental results revealed among the three chemical insecticides bioassayed, quinolphos 25 EC registered the highest LC50 value (29.7 mg a.i./L) followed by chlorpyrifos 20 EC (18.3 mg a.i./L) while the lowest LC50 value was found for lambda-cyhalothrin 5 EC (1.3 mg a.i./L) in a susceptible population of S. litura larvae. Evaluation of the seven different populations of S. litura from India showed that populations from Adilabad and Pune exhibited elevated LC50 values for chlorpyrifos [(1622.0 mg a.i./L) and (1137.0 mg a.i./L)], quinolphos [(1892.0 mg a.i./L) and (1744.0 mg a.i./L)] and lambda-cyhalothrin [(56.4 mg a.i./L) and (41.6 mg a.i./L)], respectively. Seven different S. litura populations collected varied in their resistance ratio (RR) for three conventional insecticides used in this study. For chlorpyrifos RR values ranged from 3 to 88 fold, for quinolphos RR values ranged from 3 to 63 fold and for lambda-cyhalothrin RR values ranged from 2 to 42 fold in the seven different S. litura populations compared to the susceptible population. Based on the raised LC50 values, the resistance is quite concerning for organophosphates (chlorpyrifos and quinolphos). The present study is a warning bell suggesting the cautious use of organophosphates and lambda-cyhalothrin in soybean.

The Effect of MicroRNA bantam on Baculovirus AcMNPV Infection in Vitro and in Vivo.

The role of microRNA bantam, one of the most abundant microRNAs in Sf9 cells, was studied for its role in baculovirus infection in vitro and in vivo. The expression level of bantam was increased after AcMNPV infection in Sf9 cells and in Spodoptera litura larvae. In Sf9 cells, application of bantam inhibitor or mimic altered the expression of many virus genes, the most affected gene being lef8, gp41 and p10, the expression level of which was increased by 8, 10 and 40 times, respectively, in the presence of bantam inhibitor. Virus DNA replication was decreased in the presence of bantam mimic and increased in the presence of bantam inhibitor in a dose dependent manner. However, the production of budded virus did not change significantly. Feeding the larvae of S. litura and Spodoptera exigua with bantam antagomiR, a more stable form of the inhibitor, resulted in an abnormal larval growth and a decreased pupation rate. In S. litura, larvae died 3.5 days sooner than the control when bantam antagomiR was applied, together with AcMNPV. In infected S. exigua, larval mortality increased from 47% without antagomiR to 80% with it. The results suggest that microRNA bantam plays an important role in insect growth, as well as in baculovirus-insect interaction.

Effect of granulovirus infection of Spodoptera litura (Lepidoptera: Noctuidae) larvae on development of the endoparasitoid Chelonus inanitus (Hymenoptera: Braconidae)

Infection of parasitized Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) larvae by a granulovirus (GV) deleteriously affected the development of the endoparasitoid Chelonus inanitus (Linnaeus) (Hymenoptera: Braconidae). When second-instar parasitized S. litura larvae were inoculated with GV, the percentages of emergence, pupation, and adult eclosion of C. inanitus were significantly lower from GV-infected hosts than those from uninfected ones. Lower parasitoid emergence was due to the earlier death of parasitized and GV-infected hosts and slower development of parasitoid larvae in GV-infected hosts than in uninfected ones. Some of the parasitoid larvae that emerged from GV-infected hosts died before pupation and adult eclosion as a result of lower external feeding on GV-infected cadavers. Furthermore, the body volume of parasitoids developing in GV-infected hosts was significantly lower than that of parasitoids developing in uninfected hosts. The experiment in which host cadavers and emerged parasitoids were switched revealed that external feeding of parasitoids was affected both by infection of host cadavers with GV and also by parasitoid development within GV-infected hosts. Our data show that GV infection of S. litura larvae has deleterious effects on C. inanitus development.

Bioefficacy of Catamiarus brevipennis (Servile) against two cotton pests in relation to starvation level

Considering starvations an important physiological aspect which influence the predatory behavior of insects, this study was performed to document the possible impact that starvation (2days, 4days, 6days, 8days and 10days) has on the feeding acts and prey consumption efficiency of a polyphagous predator: Catamiarus brevipennis (Servile) (Hemiptera: Reduviidae) adults. Ten-day-old adult male and female C. brevipennis fed on two common cotton pests, Dysdercus cingulatus (Fab.) adult males and females and Spodoptera litura (Fab.) third instar larvae, under laboratory conditions. The 0-day, 2-day, 4-day, 6-day, 8-day and 10-day starved predators were separately placed in transparent plastic containers containing three each of adult male and female D. cingualtus or six third instar S. litura larvae. Feeding events (capturing time and handling time) and food consumption efficiency (number of prey consumed and weight gained) were recorded. Results revealed that irrespective of the prey species, and starvation levels, C. brevipennis females captured the prey quicker, handled more prey items in time and gained more food than males. The capturing time and weight gain of the predator were directly proportion to starvation levels regardless of whether the predator was offered D. cingulatus or S. litura as food. However, after 4-day starvation, handling time was decreased when D. cingulatus was offered as a prey. Handling time increased from predators starved 0day to 2days, then decreased gradually up to 6days and again increased to 10days starved predators. C. brevipennis consumed more S. litura and subsequently gained more food than D. cingulatus. This study revealed that starvation significantly reduced the prey-capturing time and increased the food consumption and that C. brevipennis can tolerate up to 10days without any prey under field conditions, indicating that it has good biological control potential against the cotton pests.

Transcriptional profiling analysis of Spodoptera litura larvae challenged with Vip3Aa toxin and possible involvement of trypsin in the toxin activation

Vip proteins, a new group of insecticidal toxins produced by Bacillus thuringiensis, are effective against specific pests including Spodoptera litura. Here, we report construction of a transcriptome database of S. litura by de novo assembly along with detection of the transcriptional response of S. litura larvae to Vip3Aa toxin. In total, 56,498 unigenes with an N50 value of 1,853 bp were obtained. Results of transcriptome abundance showed that Vip3Aa toxin provoked a wide transcriptional response of the S. litura midgut. The differentially expressed genes were enriched for immunity-related, metabolic-related and Bt-related genes. Twenty-nine immunity-related genes, 102 metabolic-related genes and 62 Bt-related genes with differential expression were found. On the basis of transcriptional profiling analysis, we focus on the functional validation of trypsin which potentially participated in the activation of Vip3Aa protoxin. Zymogram analysis indicated that the presence of many proteases, including trypsin, in S. litura larvae midgut. Results of enzymolysis in vitro of Vip3Aa by trypsin, and bioassay and histopathology of the trypsin-digested Vip3Aa toxin showed that trypsin was possibly involved in the Vip3Aa activation. This study provides a transcriptome foundation for the identification and functional validation of the differentially expressed genes in an agricultural important pest, S. litura.

Efficacy of Steinernema spp. plus anti-desiccants to control two serious foliage pests of vegetable crops, Spodoptera litura F. and Plutella xylostella L.

Survival rates of the infective juvenile stage (IJ) of two entomopathogenic nematodes (EPN), Steinernema carpocapsae and Steinernema sp. isolate K8 (Thai isolate), plus a surfactant of 0.2% and 0.4% APSA-80™, a fire retardant gel of 0.25% and 0.5% Barricade®, and tap water were investigated by spraying the EPN suspensions (200IJs) onto kale leaf discs. Three hours after incubation, the survival rates of the EPNs plus 0.25% and 0.5% Barricade® (80.2–85.0%) were significantly higher than all other treatments (12.9–70.1%). The infectivity of the two EPNs plus 0.25% and 0.5% Barricade® against third-instar Spodoptera litura F. and Plutella xylostella L., which were evaluated by spraying 100IJs/50μl onto a 1cm kale leaf disc in the laboratory, were 82.5–100% 72h after application. In greenhouse tests, the infectivity of S. carpocapsae plus 0.25% and 0.5% Barricade® against third-instar S. litura and P. xylostella was evaluated by spaying 2500IJs/15ml/plant and assessing mortality after 72h. The results showed that the mortality rates of S. litura larvae in the S. carpocapsae plus 0.25% or 0.5% Barricade® treatment (66.0% and 61.5%, respectively) were significantly higher than in the S. carpocapsae plus tap water treatment (29.5%) and also resulted in significantly less leaf damage (11.0–11.1%) compared to control treatments (33.8–61.6%). A significant difference between the mortality rates of P. xylostella larvae (15.0–27.0%) and the percentages of leaf damage (7.1–11.0%) were also recorded for the same two treatments. Overall results were similar to previous studies which showed that fire retardant gel (Barricade®) can improve EPN virulence when they are applied to control these two insect pests. Barricade® could protect EPNs from rapid desiccation for at least 3h following application.

Effect of antibiotic on survival and development of Spodoptera litura (Lepidoptera: Noctuidae) and its gut microbial diversity.

Addition of antibiotics to artificial diets of insects is a key component in the rearing of insects in the laboratory. In the present study an antimicrobial agent, streptomycin sulphate was tested for its influence on survival and fitness of Spodoptera litura (Fabricus) (Lepidoptera: Noctuidae) as well as its gut microbial diversity. The antibiotic did not adversely affect the survival of S. litura. Faster growth of larvae was recorded on diet amended with different concentrations of streptomycin sulphate (0.03, 0.07 and 0.15%) as compared to diet without streptomycin sulphate. The overall activity of various digestives enzymes increased on S+ diet while the activity of detoxifying enzymes significantly decreased. In addition, alteration in microbial diversity was found in the gut of S. litura larvae fed on diet supplemented with antibiotic (S+) and without antibiotic (S-).

Cloning, characterization and expression of a novel haplotype cry2A-type gene from Bacillus thuringiensis strain SWK1, native to Himalayan valley Kashmir

Bacillus thuringiensis (Bt) is a gram positive bacterium which is effectively being used in pest management strategies as an eco-friendly bioinsecticide. In the present study a new cry2A gene was cloned from a promising indigenous B. thuringiensis SWK1 strain previously characterized for its toxicity against Spodoptera litura and Helicoverpa armigera larvae. The nucleotide sequence of the cloned cry2A gene pointed out that the open reading frame has 1902 bases encoding a polypeptide of 634 amino acid residues with a probable molecular weight of 70kDa. Homology comparisons showed that the deduced amino acid sequence of Cry2A had a similarity of 94% compared to that of the known Cry2Aa protein in the NCBI database and this gene has been named as cry2Al1 by the B. thuringiensis δ-endotoxin Nomenclature Committee. cry2Al1 was ligated into pET 22b vector and expressed in Escherichia coli BL21 (DE3) pLysS under the control of T7 promoter induced by isopropyl-beta-d-thiogalactopyranoside (IPTG). SDS-PAGE analysis confirmed the expression of cry2Al1 as ∼65kDa protein. Insect pest bioassays with neonate larvae of S. litura and H. armigera showed that the purified Cry2Al1 are toxic to S. litura and H. armigera with LC50 2.448μg/ml and H. armigera with 3.374μg/ml respectively.

Effects of perchlorate bioaccumulation on Spodoptera litura growth and sex ratio.

Perchlorate (ClO4 (-)) pollution is widespread in the natural environment, but the effects of ClO4 (-) on the terrestrial insects are rarely studied. Here, when phytophagous insect Spodoptera litura larvae were fed on the diets with different ClO4 (-) concentrations, changes in their life-history traits were recorded; ClO4 (-) accumulations in feces and insect body were detected. The results demonstrated that ClO4 (-) bioaccumulation in insect at the different developmental stages was ranked in the order: adults > pupae > the 4th > 5th > 6th instar larvae. Besides, ClO4 (-) accumulations in the feces were ranked in the order: the 6th > 5th > 4th instar larvae. The ClO4 (-) accumulations in female pupae and adults were significantly higher than that in males. ClO4 (-) bioaccumulation in insect prolonged larval development time and caused a skewed sex ratio (the percentage of males at metamorphosis significantly decreased) under 100 to 200mg ClO4 (-)/kg treatment. Therefore, ClO4 (-) accumulations in S. litura body presented developmental stage-, sex-specific pattern, and the sex-specific ClO4 (-) accumulations resulted in difference of sex ratio. These effects were observed at concentrations reported in natural environments contaminated with ClO4 (-), suggesting that this contaminant may pose a threat to the normal development and growth of this insect species.

Effect of Cadmium and Lead Exposure on Tissue Specific Antioxidant Response in Spodoptera litura

Introduction: Oxidative stress in insects may result from an imbalance of oxidants and antioxidants under a significant impact of metals. Reactive oxygen species (ROS), such as superoxide, hydrogen peroxide, and hydroxyl radical, are generated from normal metabolic processes in all oxygen-utilizing organisms. In the present study was designed to the impact of heavy metal (Cadmium and Lead) toxicity and its free radical scavenging enzymes in Spodoptera litura larvae. Methods: Heavy metals were administered using artificial diet method having different concentrations. The metal toxicity was observed after 24 and 48 hrs post treatment. In antioxidant parameters were SOD, CAT, POX, GST, LPO, ACP and AKP were assessed. In additionally metal accumulation analysis using ICP-MS. Results: In particular, after exposure to diets containing environmentally relevant concentration (Cd 0.3 mg, Cd 0. 44 mg, Cd 0.50 mg or Pb 0.48 mg, Pb 4.8 mg, Pb 9.6 mg) at 48 hrs changes in the activity of antioxidant enzymes were measured in larvae. The results showed that compared with control, the based on concentration significantly increased of antioxidant enzymes activities. In ICP-MS analysis results shows based on the concentration Pb 9.6 mg, 325.61 ppm/mg -1 and Cd 0.44 mg, 36.5 ppm/mg -1 will be increased. Conclusion: In conclusion antioxidant systems of S. litura were altered by Cd and Pb exposure as determined by measuring in the enzymes activities. All of Cd and Pb result in strong oxidative stress and toxicity to S. litura larvae. Based on the results we suggest that metal toxicity and metal accumulation of insects influenced by Cadmium chloride and Lead nitrate in S. litura larvae.

Beberapa Aspek Biologi Parasitoid Apantheles sp pada Inangnya, Spodopera litura, Fab. setelah Perlakuan Ekstrak Daun dan Ranting Aglaia odorata (Lour)

The objectives of this study were to evaluate effect of leaf and branch extract of the Aglaia odorata against: emergences of adult Apantheles sp emerged from S. litura larvae, (2) the extract effect to live cycle and reproduction of Apantheles sp (3) and its effect against the morphology character some of parasitoid. The metode was used by of leaf-dip method. The leaf and branch effectivity bioassay used by of Ricinus communis leaf . The leaf disk were dipped in the extract solution on six concentration for 10 s, and air dried. Each leaf disks was placed six bottles glass and ten larvae were placed in each botlle, each concentration was replicated four time. Data collected were subjected an anaysis of variance followed by mean comparation based of Duncan´t New Multiple Range Test. The imago Apantheles sp. emerged from host, S. litura larvae was recorded of live cycle, its reproduction, and morphology character. The result showed that the length of pre adult stage of emerging parasitoids from of S. litura larvae treated with 85,99 ppm was 45 percent, and with 21,95 ppm was 22,22 percent. The extract toxicity to natural enemies such as parasitoids relatively non toxis. The live cycle of female adult parasitoid was 16,90 and 6,20 days. Reproduction capacity of adult female parasitoids of 85,99 mg/L was 69,4 eggs/adult, which was statistically different from control, whereas of 21,95 treatment, it was 65,40 eggs/adult and its was not significant to control. Key words: Aglaia odorata, Lour, Spodoptera litura,, morphology character, Apanteles sp

PM 7/124 (1) Spodoptera littoralis, Spodoptera litura, Spodoptera frugiperda, Spodoptera eridania

Contents Specific scope 410 1. Introduction 411 2. Identity 411 3. Detection 411 4. Identification 412 4.1. Morphological identification 412 4.1.1. Eggs 412 4.1.2. Larvae 412 4.1.2.1. Introduction 412 4.1.2.2. General description Spodoptera larvae 413 4.1.2.3. Spodoptera littoralis and S. litura 414 4.1.2.4. Spodoptera eridania 417 4.1.2.5. Spodoptera frugiperda 419 4.1.2.6. Possible confusion with Spodoptera exigua 421 4.1.3. Pupae 422 4.1.3.1. General description 422 4.1.3.2. Possible confusion with Spodoptera exigua 422 4.1.4. Adults 422 4.1.4.1. Introduction 422 4.1.4.2. Spodoptera littoralis 424 4.1.4.3. Spodoptera litura 425 4.1.4.4. Spodoptera eridania 427 4.1.4.5. Spodoptera frugiperda 429 4.2. Molecular methods 430 5. Reference material 430 6. Reporting and documentation 430 7. Performance criteria 430 8. Further information 431 9. Feedback on this diagnostic protocol 431 10. Protocol revision 431 11. Acknowledgements 431 12. References 431 Appendix 1: Features of Lepidoptera larvae 433 Appendix 2: Keys to adults based on external morphology 434 Appendix 3: Information on genitalia 435 Appendix 4: Identification of Spodoptera eridania and S. frugiperda using real‐time PCR 441 Appendix 5: Identification of Spodoptera littoralis and S. litura using real‐time PCR 442 Specific scopeThis Standard provides guidance for the identification of S. littoralis, S. litura, S. frugiperda and S. eridania.Specific approval and amendmentThis Standard was approved in 2015‐09.

Evaluation and characterization of trypsin inhibitor from rice bean with inhibitory activity against gut proteases of Spodoptera litura.

Trypsin inhibitor (TI) in rice bean (Vigna umbellata) varied spatio-temporally in different parts of the plant, with the highest level (30.9 mg/g d.w.) noted in the maturing seeds of genotype BRS-2 at 160 days after planting (DAP). The TI from rice bean seeds was isolated and purified approximately 182-fold, with a final yield of 29% using ammonium sulfate precipitation, ion exchange chromatography through DEAE-Sepharose, gel permeation through Superdex-75, and finally by affinity chromatography using a trypsin-Sepharose column. The purified TI showed a single band on SDS-PAGE under reducing conditions with an apparent molecular mass of 24 kDa. The highest activity of purified inhibitor (about 90%) was recorded at pH 4.0 at 37 °C, suggesting the stability of the inhibitor under acidic conditions. The TI exhibited an inhibitory effect against Spodoptera litura larvae. A progressive decline in larval weight, growth, and survival rate of larval development was observed after feeding S. litura larvae on a diet supplemented with increasing concentrations of rice bean TI. The highest TI content in the seeds nearing maturity correlates to the role of TIs in protecting against insect pests. The study clarifies the role of rice bean protease inhibitors as a potential strategy against insectpests of economic importance.

Sclerotium rolfsii lectin expressed in tobacco confers protection against Spodoptera litura and Myzus persicae

Bacillus thuringiensis (Bt) toxins expressed in GM crops provide effective protection against chewing-type insects but fail to control damage by sucking pests, leading to a search for a newer class of efficient entomotoxic proteins. In this direction lectins with novel sugar-binding properties showing toxicity to a wide range of agricultural insect pests are being evaluated for the insecticidal efficacy. Our previous study demonstrated the potential toxic effect of O-glycans sugar-specific Sclerotium rolfsii lectin (SRL) supplemented through an artificial diet on the growth and survival of Spodoptera litura larvae by binding to midgut epithelial cells. Considering the significance of its entomotoxic property, we cloned the SRL gene and expressed it in a prokaryotic host, which showed 97 % sequence homology to the native SRL. Recombinant SRL (recSRL) exhibited a carbohydrate-binding property and insecticidal activity similar to native SRL. The SRL gene was transferred into tobacco plants by Agrobacterium-mediated transformation and expressed constitutively using a CaMV35S promoter. Integration and stability of the SRL gene was confirmed by Southern hybridization. recSRL expressed in the transgenic tobacco leaves was analyzed by Western blotting and quantified by ELISA, which accounted for 0.47 % of the total soluble leaf proteins. Bioassays conducted on second instar S. litura larvae fed on transgenic tobacco leaves showed 90 % larval mortality in 48 h and in planta assays using M. persicae demonstrated an 81.90 % population reduction. These findings indicated that the ectopically expressed SRL conferred protection against target pests of lepidopteran and hemipteran orders.

Insecticidal Constituents and Activity of Alkaloids from Cynanchum mongolicum

Based on MS and NMR data and bioassay-guided tracing, three insecticidal alkaloids I, II and III from Cynanchum mongolicum were identified to be antofine N-oxide, antofine and tylophorine. Alkaloid I was more toxic than alkaloids II and III, but they were less active against Spodoptera litura than total alkaloids. The contact toxicity from these alkaloids against the aphid Lipaphis erysimi was significant, as the 24 h-LC50 values of alkaloids I, II, III and total alkaloids were 292.48, 367.21, 487.791 and 163.52 mg/L, respectively. The development disruption of S. litura larvae was tested, the pupation and emergence rates of S. litura decreased and the acute mortality of S. litura increased significantly by day 3 after being injected in their body cavity with 10–40 mg/L of total alkaloid. The ecdysone titer of treated S. litura larvae and prepupae declined with increasing alkaloid concentration. The alkaloids of Cynanchum mongolicum are potential insect growth inhibitors.

EXPLORATION OF POTENTIAL PLANTS AS A BIO-INSECTICIDE AT ITS SURABAYA CAMPUS

<p>ITS Surabaya campus has a biodiversity potential, especially plants that can be utilized. Different types of plants have been known as a potential insecticide because they contain bioactive compounds, such as essential oils, saponins, tannins, alkaloids, phenolics, flavonoids, alkenes and these terpenoids. This research was a descriptive experimental, which aimed to explore the vegetation potential as plant-based insecticide or bio-insecticide. Tracking method to obtain plant leaves samples in ITS campus was used in this study. Leaf extracts were obtained using methanol solvents after the freeze-drying method that will change leaf into powder form. The extracts were then stored in the refrigerator and ready to be applied. Leaf dipping method was used as biological test. The test conducted on Spodoptera litura larvae that obtained from Balittas Malang. Larvae rearing trials were carried out in the Laboratory of Botany, Department of Biology ITS. The larvae examined were the third instar fed on fodder greens of leaf mustard. Toxicity effects of extract were observed from mortality of Spodoptera litura during 5 days. Ten plants species with bio-insecticide potential in this study were Ageratum conyzoides L., Crynum asiaticum L., Calotropis gigantea R., Eugenia cumini Merr., Eichornia crassipes, Crescentia cujete L., Nothopanax scutellarium Merr., Morinda citrifolia L., Azadirachta indica, and Lantana camara L. <br /><strong></strong></p><p><strong>Keywords</strong> : Bio-insecticide, potential plants, Spodoptera litura</p>

THE POTENTIAL OF SUBCULTURE Helicoverpa armigera NUCLEAR POLYHEDROSIS VIRUS (HaNPV) TO BE UTILIZED AS AN ALTERNATE SYNTHETIC INSECTICIDES TO CONTROL INSECTS PESTS IN CABBAGES PLANTATION (Brassica oleracea var. capitata L)

<p>Subculture Helicoverpa armigera Nuclear Polyhedrosis Virus (HaNPV) is an entomopathogenic viruses isolated from cadaver of Helicoverpa armigera larvae, and was succesfully produced in Spodoptera litura larvae as an alternate host. These viral agent have been applied to control the population of three species insects pests Spodoptera litura, Crocidolomia pavonana and Plutella xyllostella which were infested in Cabbages Plantation. The concentration of virus of 4 x 107 Polyhedral/ml was sprayed in cabbage leaves 24 hours before infested of larval and every four days after. The research used randomized design which consisted of factor (three species of second instar larvae, S. litura, C. pavonana, P. xyllostella) and eight replications. The result showed that the three species of larval were sensitive against subculture HaNPV infection. The mortality of each larval species (S. litura, C. pavonana and P. xyllostella) were 100%, 97.5% and 98.7%. Subculture HaNPV can be utilized to control the population of three spesies of insects pests in Cabbage Plantation. </p><p>Keywords : Subculture HaNPV, Polyhedral</p>

Identification and Characterization of CYP9A40 from the Tobacco Cutworm Moth (Spodoptera litura), a Cytochrome P450 Gene Induced by Plant Allelochemicals and Insecticides.

Cytochrome P450 monooxygenases (P450s) of insects play crucial roles in the metabolism of endogenous and dietary compounds. Tobacco cutworm moth (Spodoptera litura), an important agricultural pest, causes severe yield losses in many crops. In this study, we identified CYP9A40, a novel P450 gene of S. litura, and investigated its expression profile and potential role in detoxification of plant allelochemicals and insecticides. The cDNA contains an open reading frame encoding 529 amino acid residues. CYP9A40 transcripts were found to be accumulated during various development stages of S. litura and were highest in fifth and sixth instar larvae. CYP9A40 was mainly expressed in the midgut and fat body. Larval consumption of xenobiotics, namely plant allelochemicals (quercetin and cinnamic acid) and insecticides (deltamethrin and methoxyfenozide) induced accumulation of CYP9A40 transcripts in the midgut and fat body. Injection of dsCYP9A40 (silencing of CYP9A40 by RNA interference) significantly increased the susceptibility of S. litura larvae to the tested plant allelochemicals and insecticides. These results indicate that CYP9A40 expression in S. litura is related to consumption of xenobiotics and suggest that CYP9A40 is involved in detoxification of these compounds.

Development and testing of mycopesticide formulations of Metarhizium anisopliae for shelf life and field application against Spodoptera litura larvae

Conidiospores of the entomopathogenic fungus Metarhizium anisopliae were produced by solid state fermentation using sorghum/barley/rice grains. Shelf life and viability of oil formulatations as well as unformulated infective propagules was tested by germination bioassay and pathogenicity studies on Spodoptera litura larvae. Viability of unformulated conidiospores stored at three temperatures (4°C, -30°C and room temperature) was understood using germination bioassay. Studies on seven oil formulations and two powdered formulations for shelf life at 4°C, revealed 60% viability of conidiospores formulation with gingelly oil, stored for six months. Virulence of the infective propagules studied against third instar Spodoptera litura larvae during six months storage demonstrated insect mortality ranging from 40 to 88.33% with LT50 values of 4.63 to 13.07 days. Field application of infective propagules on Vigna sinensis crop heavily infested with S. litura suggested insect mortality ranging from 51.35% to 88.65% at 1X10 12 conidia/ ml of gingelly oil formulation.

Mahogany Wood-Waste Vinegar as Larvacide for Spodoptera litura

The carbonization of lignocelullosic waste to obtain wood vinegar (WV) was investigated in this work. WV was used as a botanical insecticide against armyworm (Spodoptera litura), which is known as a major pest of soybean crops in Indonesia. This study includes the following: (i) the assessment of potential use of lignocellulosic waste from mahogany wooden-sandal home industry; (ii) the determination of the yield of various components of carbonization process, from each unit of the waste; and (iii) the application of the produced WV as larvicide on S. litura larvae in the laboratory. The experiments were arranged in a completely randomized design, and the observed variables included mortality and anti-feedant activity of S. litura larvae. The data were analyzed using analysis of variance with Duncan’s multiple differences test. The results showed that the amount of wood waste generated at wooden-sandal craftsman level was 16.12%. Carbonization of 1,000 g of the wood waste yielded WV, tar, bio-oil, and char in quantities of 442.68 g, 36.5 g, 4.04 g, and 251 g, respectively. The treatment using WV concentration of 1.5% to 3.0% showed low larvacidal action, which gave LC50 value of 12.82%, but it had adequate anti-feedant activity.