Instar Larvae Of Spodoptera Litura Research Articles

Screening of Adjuvants as Sunlight Protectant for NPV and Evaluation of Storage Conditions against <i>Spodoptera litura</i>

This experimental study evaluated the effect of adjuvant supplementation on larval mortality of nuclear polyhedrosis virus under sunlight. Study revealed that Tinopal @1% provided best protection from sunlight and retained viral efficacy up to 68.75 and 66.75% in SpltNPV (native) and SpltNPV (NIPHM) respectively, against third instar larvae of Spodoptera litura (F). However, all adjutants resulted in significantly higher larval mortality as compared to control (virus alone) under sunlight. SpltNPV viral formulations stored at different storage conditions recorded minimum reduction in larval mortality, when stored in amber coloured glass bottle at refrigeration temperature (4± 2°C).

Uji Efektivitas Bioinsektisida Beauveria Bassiana Bals, Vull. (Bassikoka) Terhadap Larva Instar III Spodoptera Litura Pada Tanaman Sawi (Brassica Juncea L.)

This study aims to obtain data on the effectiveness of several concentrations of Beauveria bassiana (BASSIKOKA) against the third instar pest Spodoptera Litura on mustard greens. This research was conducted at the Laboratory of Pests, Faculty of Agriculture, University of Pattimura. This study used a completely randomized design with Beauveria bassiana (Bassikoka) bioinsecticide treatment with a concentration of 0.1g/L of water, 0.2g/L of water, 0.3 g/L of water, 0, 4 g/L, and control as comparison. Observations were made on the initial symptoms of infection, mortality, and the fastest time to kill 50% of the third instar larvae of Spodoptera litura. Based on the results of the study, it can be concluded that the concentration of 0.4 g/L bioinsecticide Beauveria bassiana (Bassikoka) is effective against third instar larvae of Spodoptera litura L. with a mortality rate of 90% and the fastest time to kill 50% of third instar larvae of Spodoptera litura 2.4 days.

LC–MS/MS analysis of carcinogenic tobacco-specific nitrosamines in Spodoptera litura using the QuEChERS method

Nicotine is a highly addictive alkaloid and a neurostimulator found in tobacco that causes addiction in humans and makes tobacco a high-demand commercial product. It is popularly used for recreational purposes and is a harmful substance (Oral LD50 value for rat is 50 mg/kg) and causes addiction. The metabolites of nicotine such as the Tobacco-specific Nitrosamines (TSNAs) are hazardous substances whose metabolites are highly electrophilic and form DNA adducts, which will initiate the process of carcinogenesis. TSNAs are formed during curing, storage and fermentation due to the nitrosation of nicotine and other tobacco alkaloids. TSNAs are used as biomarkers for cancer risk assessment in humans exposed to tobacco and its products. To determine the occasional formation of TSNAs in tobacco-feeding insects, 5th instar larvae of Spodoptera litura and their faeces were analyzed for the presence of N′-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) along with the stored tobacco leaves (PT-76) using an Agilent 6470B LC–MS/MS system following ISO/DIS 19290:2015 protocol. The larvae are extracted in a buffered acetonitrile–water extraction and the amount of TSNAs are quantified in multiple reaction monitoring (MRM) mode. 20 upmul of each extracted and cleaned up sample was injected into the LC–MS/MS system for quantification. The Limit of Detection (LOD) and Limit of Quantification (LOQ) were 0.001 mg/kg and 0.005 mg/kg for all the tested nitrosamines. NNN was found to be 0.361 mg/kg, 0.340 mg/kg, and 5.66 mg/kg in insect whole-body samples, faeces, and tobacco leaves, respectively. NNK was found to be 0.060 mg/kg, 0.035 mg/kg and 0.93 mg/kg in insect whole body samples, faeces and tobacco leaves, respectively. However, NNAL was not detected in both the insect’s whole body and faeces. Recoveries ranged between 95 and 98% for all compounds when spiked at LOD and LOQ. The presence of TSNAs is a biomarker for cancer risk and their presence in insects would point to cancer risk assessment in tobacco feeding insects and any possible TSNA-detoxifying pathways in insects that might prevent mutagenesis caused these compounds.

Biological and in vitro effects of Neem (Azadirachta indica) extract on second and third instar larvae of Spodoptera litura

Spodoptera litura is a major threat to agricultural crops all over the world including Pakistan. It has developed resistance to several chemicals, especially synthetic insecticides. Plant based chemicals like extracts may serve as suitable and alternative biocontrol methods for pests in the future. The current study was conducted to determine the biology of S. litura on cabbage and the effects of two botanicals i.e. Azadirachta indica and Eucalyptus globulus against 2nd and 3rd instar larvae in controlled conditions. The incubation period of pest was 3-4 days. The average mean developmental period of 1st, 2nd, 3rd, 4th, and 5th larval instar was 2.44±0.71, 2.32±0.74, 3.43±0.68, 2.76±0.80, and 2.40±0.79 days, respectively. The pre-ovipositional, and ovipositional period of females was 2.04-3.58 and 2.89-5.71 days respectively. The total life cycle of pests was 30.83-38.79 days. Significantly higher mortality of 2nd and 3rd instar larvae was recorded in A. indica. The percentage of mortality increased with an increase in treatment time.

Effect of daidzein on growth, development and biochemical physiology of insect pest, Spodoptera litura (Fabricius)

Anti- insecticidal potential of daidzein was studied by feeding second instar larvae of Spodoptera litura (Fabricius) on artificial diet incorporated with different concentrations (5 ppm, 25 ppm, 125 ppm, 625 ppm) of diadzein. Results revealed high larval mortality, prolongation of pupal and total developmental period of the larvae treated with diadzein. Anti-nutritional/post ingestive toxicity of diadzein was also revealed by the decrease in the nutritional indices such as relative growth rate (RGR), relative consumption rate (RCR), efficiency of conversion of digested food (ECD), efficiency of conversion of ingested food (ECI) and approximate digestibility (AD). The suppression of immune function due to decline in the total hemocytes count was also observed in treated S. litura larvae. Profiles of detoxifying enzymes viz. superoxide dismutases (SOD), catalase (CAT), ascorbate peroxidases (APOX) and glutathione S-transferase (GST) were also significantly increased with diadzein treatment. The hydrogen peroxide content (H2O2), lipid peroxide content (LP) and protein carbonyl content were also significantly enhanced in the treated larvae thus, indicating oxidative stress in the insect. Our findings suggest that daidzein can be used as the alternative to conventional pesticides for controlling S. litura population.

Bio-efficacy of Geobacillus thermodenitrificans PS41 against larvicidal, fungicidal, and plant growth-promoting activities.

The microbial interactions with plant hosts were known to establish plant growth and beneficial productivity. Some bacteria, fungi, actinomycetes, yeast, and algae have proven as potential effective microbes in agricultural field. In this study, the insecticidal effect of Geobacillus thermodenitrificans PS41 secondary metabolites was tested against third instar larvae of Spodoptera litura, with mortality rate 60.26 ± 1.5% which might influence the agropest management. The test bacterial metabolites were subjected to GC-MS analysis. Totally, 17 different compounds were identified from the ethyl acetate extract metabolites of PS41 strain. The highest peak was obtained with behenic alcohol compound followed by 1-octadecene and penta erythrityl tetrachloride. The Geobacillus thermodenitrificans PS41 secondary metabolites showed potential antifungal activity against plant pathogenic fungi. The highest inhibit was attained against Cladosporium sp., (25 mm) followed by Rhizoctonia solani and Alternaria brassicola (23 mm). However, no toxic effect was exerted upon earthworm (Perionyx excavatus) when treated with PS41 bacterial metabolites. The potential PS41 strain was also found supporting the plant growth. The potential bacterial strain PS41 did not show antagonistic activity against soil bacteria such as Rhizobium sp., Azotobacter sp., Azospirullum brasilense, Pseudomonas fluorescens and Bacillus megaterium. The potential test organism, Geobacillus thermodenitrificans PS41, possessing biopesticide and biofertilizer properties can be a suitable ecofriendly organic applicant in agricultural field for enhancing crop production.

Efficacy of Zinc Oxide Nanoparticle Adding to Two Neonicotinoids Pesticides against Spodoptera litura (Lepidoptera: Noctuidae) and Aphis gossypii Glover

In recent years, pesticide residues have become a danger to the food chain, the environment, and human health. Some nano metal oxides had been applied with pesticides to solve these problems and enhanced their insecticidal Activity. This new technology for the complete mineralization of pesticides is necessary to convert them to non-toxic forms. In this study, we investigated the synergistic effect of ZnO nanoparticles (NPs) with some neonicotinoid pesticides (Thioxam 25%WG and Actara 25% WP) against 4th instar larvae of Spodoptera litura (Lepidoptera: Noctuidae) and cotton aphid, Aphisgossypii Glover (Homoptera: Aphididea). These cotton pests were allowed to feed on castor leaves after impregnated with pesticides at recommended rate with the composite of ZnO (NPs). Observations showed an increase in mortality (48.57 %, 93.51 % increased mortality). The addition of the ZnO nanoparticles to insecticides increased the insecticidal activities and a reduction (%) against tested cotton pests. The synthesized nano metal oxide was characterized by different techniques as FTIR spectroscopy, TEM and UV spectroscopy used for a determination band gap of the prepared ZnO NPs. This present study suggests that nanoparticles metal oxide as (ZnO) applying as eco-friendly nanomaterial in the field of pest control.

Synergistic mechanism of insecticidal activity in basil and mandarin essential oils against the tobacco cutworm

Owing to the complexity in the chemical composition of plant essential oils, they often display enhanced insecticidal activity when applied as a mixture. Although the insecticidal activity of plant essential oils has been gaining more attention recently, understanding in the mechanism of synergy has not been studied as much. In the present study, insecticidal activity of 28 individual essential oils and their mixtures against the third instar larvae of Spodoptera litura was examined. Among the oils tested, basil oil exhibited the strongest contact toxicity, and mandarin oil displayed the greatest boosting effect when the remaining oils were mixed with basil oil. Estragole and linalool were determined as the major active constituents for the insecticidal activity of basil oil and limonene for mandarin oil from the chemical analyses and compound elimination assay. Based on the LD50 values, the binary mixture of basil and mandarin oils exhibited enhanced toxicity compared to the individual application of the two oils, showing synergy ratios of 1.3 and 1.4 from two statistical models. As for the major active compounds, synergistic interaction was found in tertiary mixture of estragole, linalool, and limonene in the blending ratio of 7:2:7, displaying the same insecticidal activity of the binary mixture of basil and mandarin oils. The synergistic effect was only observed in the tertiary mixture, indicating each compound play crucial roles of the overall contact toxicity. Increased penetration through cuticular layer and amplified neurophysiological response were proposed for the mechanism of synergistic effect.

Larvicidal toxicity of various insecticides against Tobacco caterpillar, Spodoptera litura, Fabricius (Lepidoptera: Noctuidae)

The present study was envisaged to check the toxic effect of certain insecticides (chlorpyriphos, spinosad, novaluron, acetamiprid and thyme oil) on third instar larvae of Spodoptera litura by using three different bioassays i.e. topical treatment, leaf dip and artificial diet method at different concentrations viz., 5, 25,125 and 625 ppm. Observations on larval mortality were recorded from each treatment at 24, 48 and 72 hours intervals. Spinosad was found to be most toxic on the basis of larval mortality followed by chlorpyriphos, novaluron, thyme oil and acetamiprid in topical bioassay. But in leaf dip bioassay, thyme oil at 5 ppm caused 100 percent larval mortality. Acetamiprid proved as poor insecticide against this pest causing 26.66, 16.66 and 10 percent mortality after 72 hours of treatment in topical, leaf dip, and artificial diet bioassay at highest concentration, respectively. In artificial diet method, highest mortality percent was recorded in chlorpyriphos and spinosad i.e. 86.66 percent after 48 and 72 hours of treatment, respectively.

Toxicity of Bacillus thuringiensis against second instar larvae of Spodoptera litura on different host plants

Spodoptera litura is serious pest of many horticultural and agricultural crops. S. litura can cause severe economic loss of crops like cotton, cabbage and okra. Different methods are adopted to control this notorious insect pest throughout the globe but biological control is one of them that proved best against it. In 2019, current study was conducted to check the toxicity of Bacillus thuringiensis on 2nd larval instars under laboratory conditions by using different hosts. Mortality data was recorded at 24, 48 and 72 hours of post treatment. The results showed that maximum mortality was recorded on okra (41.46%) followed by cotton (34.67%) and cabbage (23.87%) after 24 hours. After 72 hours of post treatment, maximum mortality of larvae was observed on Bt treated leaves of cabbage than okra. The results indicated that 100% mortality was recorded on cabbage after 72 hours of treatment. Bt treated cabbage leaves were found most effective with 11.21% mortality while cotton gave least effective results with 9.99%. The current study concluded that microbial control is best approach to control insect pest under laboratory as well as field conditions.

Antifeedant and larvicidal activities of leaf essential oils from Hyptis suaveolens (L.) Poit., Chromolaena odorata (L.) R.M. King and Lantana camara L. against Spodoptera litura Fab. (Lepidoptera: Noctuidae)

The current study was carried out to evaluate antifeedant and insecticidal activities of three essential oils from leaves of Hyptis suaveolens, Chromolaena odorata and Lantana camara against fourth instar larvae of Spodoptera litura under the laboratory conditions. Results indicated that the essential oil from leaves of Hyptis suaveolens had a strong antifeedant impact on the larvae with antifeedant index (AI) of 75.4, 88.5 and 92.9 when leaf disks of Ipomoea batatas were treated with the essential oil at concentration of 1.5, 2.0 and 2.5 %, respectively. Also dose dependent mortalities were observed in the larvae topical treated with the essential oil at different concentrations. At the treated concentration of 0.4 mg per each larva, 68.3 % of the larvae were killed after 24 hours, and 25.0 % were died at the pupal stage after 30 days of observation. At the concentration of 1.2 mg/larva, 93.3 % of the larvae were killed after 24 hours, and no emergence of adults was recorded after 30 days of observation. Larvicidal activity of the H. suaveolens essential oil (with the lethal doses LD50=0.16 and LD95=1.52 mg/larva) was stronger than those of the C. odorata and L. camara essential oils (with LD50=0.57–0.63 and LD95=4.64–4.97 mg/larva) after 24 hour of treatment. GC–MS analysis indicates that the major volatile components of the essential oil from leaves of H. suaveolens are composed of b-caryophyllene (30.0 %), eucalyptol (12.0 %), copaene (5.9 %), and a-bergamotene (5.7 %). This essential oil needs to be further investigated and used as a bio-insecticide for control of S. litura.

Enhanced Insecticidal Activity of Thiamethoxam by Zinc Oxide Nanoparticles: A Novel Nanotechnology Approach for Pest Control.

Indiscriminate and unregulated application of pesticides produces deleterious effect in various groups of organisms including humans and the environment. To solve these issues, it has been reported that the residue-free green nanocomposite synergistically enhances the pesticide efficacy. In this study, ZnO nanoparticles (NPs) with a thiamethoxam nanocomposite were synthesized and we investigated their synergistic effect on 4th instar larvae of Spodoptera litura (Lepidoptera: Noctuidae). These larvae were allowed to feed on the composite of ZnO NPs with thiamethoxam (10–90 mg/L) and thiamethoxam-impregnated castor leaves. Observations showed an increased larval mortality (27% increased mortality), a malformation in pupae and adults, overdue emergence, and reduced fecundity and fertility. A significant dose-dependent variation in the biochemical parameters such as superoxide dismutase (SOD), glutathione-S-transferase (GST), and thiobarbituric acid-reactive substances (TBARS) in the treated larvae was also observed. A decline of 72.42 and 33.82% in SOD and GST activity ,respectively, was observed at higher concentration as compared to the control. On the contrary, it enhanced the TBARS level up to 56.7%. The synthesized nanocomposite was characterized by different biophysical techniques such as X-ray diffraction (average crystalline size 34 nm), scanning electron microscopy, transmission electron microscopy (average particle size 30 nm), and Fourier transform infrared spectroscopy (Zn–O stretching peaks at 432 cm–1 and 503 cm–1). The observation of the present study suggests that ZnO NPs pave the way for developing cost-effective, eco-friendly, and capable nanomaterial for its applications in the field of biological sciences.

Antifeedent activity of ecofriendly phyto-insecticides against Spodoptera litura

Among the hexane and ethyl acetate neem extracts, highest antifeedancy of 89.33% was recorded in ethyl acetate at 10% concentration. The results of the laboratory evaluation of the Nerium oleander crude solvent extracts with regard to the poison food technique showed that with increasing concentration the feeding deterrence action increased against third instar larvae of Spodoptera litura and at the maximum concentration tested was recorded as 81.22 and 78.35 per cent at ethyl acetate and diethyl ether nerium crude extract, respectively. Both neem and Nerium showed higher antifeedant activity against S. litura with 10% concentration of ethyl acetate.

Effect of buprofezin on the growth, development and morphometric parameters of Spodoptera litura (Fabricius) (Order: Lepidoptera, Family: Noctuidae) adult

The experiments were conducted to know the efficacy of Buprofezin (Award 40 SC), an insect growth regulator against 2nd instar larvae of Spodoptera litura (Fabricius) under laboratory conditions (insect rearing was done at room temperature and relative humidity that is 260C-300C and 65-80% relative humidity) at three different concentrations viz. 200, 400, and 600 ppm through three different application methods like direct or topical, indirect or leaf-dip and combined. The experiment was laid out in complete randomized design (CRD) with three replications and ten 2nd instar larvae of Spodoptera litura were used for each replication. Results revealed that this growth regulator strongly arrested the growth and development of S. litura (Fabricius) from larval stage to adult. The treated data were recorded after adult emergence and compared with untreated control adult. The results clearly showed that Buprofezin had significant effect on the inhibition of adult weight; wing length and width compared to control and consequence were clearly dose, time and method dependent. As well as we are hopeful because we found some abnormal adult from the treated larvae that may increase the potentiality of Buprofezin as an excellent tool of IPM. The maximum, 54.53% adult weight reduction was recorded from 600 ppm of Buprofezin through combined application method which was followed by leaf-dip (46.41%) and topical application method (39.86%). Similarly, 23.13% wing length and 22.27% wing width were inhibited when larvae were treated with 600 ppm through combined application method compared to control. The 2nd best result was found from 400 ppm and leaf-dip application method. The dose, 200 ppm and topical application method was found to be less effective compared to the rest of the two doses or two application methods. So this is the demand of the current situation to evaluate this selective bio-rational molecules against S. litura as the alternatives of conventional insecticides to combat resistance development, effective larval control, inhibition of growth and development, to keep the natural enemies safe and fit these molecules in IPM packages individually or combindly.
 
 J Bangladesh Agril Univ 17(4): 514–520, 2019

Molecular characterization of lepidopteran-specific toxin genes in Bacillus thuringiensis strains from Thailand.

A total of 511 local isolates of Bacillus thuringiensis from different geographical regions of Thailand were analyzed for the presence of the cry1A, cry1B, cry2A, cry9, and vip3A genes encoding for lepidopteran-specific toxins. PCR results revealed that 94.32% (482/511) of B. thuringiensis isolates harbored at least one of the detected genes, of which the cry1A, cry1B, cry2A, cry9, and vip3A genes were detected at frequencies of 90.61%, 89.63%, 76.32%, 40.70%, and 48.18%, respectively. Nineteen gene-combination profiles were discovered among 482 B. thuringiensis isolates, of which the most frequently detected profile contained the cry1A, cry1B, cry2A, and vip3A genes. Sixty-one isolates (12.66%), which harbored all of the detected insecticidal toxin genes, were further detected for the exochitinase (chi36) gene and chitinase activity. The results revealed that all 61 isolates contained the chi36 gene and exhibited chitinase activity. Insect bioassays showed that five isolates were highly toxic (more than 80% mortality) against second instar larvae of Spodoptera litura, of which the highest insect mortality (93%) was obtained from the B. thuringiensis isolates 225-15 and 417-1. Scanning electron microscopy revealed that the crystal morphologies of the five effective isolates were bipyramidal and cuboidal shapes. SDS-PAGE analysis of the spore-crystal mixture showed major bands of approximately 65 and 130kDa. These five effective strains are alternative candidates for use as a microbial insecticide for the control of the S. litura pest.

PEST CONTROL POTENTIAL OF CYCLOSOROUS INTERRUPTUS, CHRISTELLA DENTATA AND NEPHROLEPIS CORDIFOLIA ON THE BIOLOGY OF SPODOPTERA LITURA (FAB.)

The present experiment was designed to investigate the pesticididal property of the chosen ferns viz., Cyclosorus interruptus (Willd.) H.Itô (Theylepteridaceae), Christella dentata (Willd.) (Forssk.) Brownsey et Jermy (Theylepteridaceae), and Nephrolepis cordifolia (L.) Presl. Phytochemical analysis carried out using methanol extracts of the experimental ferns revealed the presence of the secondary metabolites like alkaloids, steroids, tannins, flavonoids, cardiac glycosides and phenolic compounds in methanolic extracts of the experimental ferns. The nano particles of chosen fern extracts synthesized using silver nitrate (AgNO3) showed the characteristic colour change from pale yellow to dark brown indicated the synthesis of silver based nano particles. The UV- Visible spectrum obtained for the silver nanoparticles (AgNPs) of the experimental ferns confirmed the synthesis of nanoparticles (433.50 nm, 447.00 nm and 444.00 nm for C. interruptus, C. dentata and N. cordifolia, respectively). Bioassay on the pesticidal property of the methanol extracts and ferns-AgNP were evaluated against third instar larvae of Spodoptera litura (Fab.) (Lepidoptera: Noctuidae). The results of the bioassay revealed the impact of methanolic extracts and their AgNP particles on the developmental period, pupal weight, percentage of pupation and adult emergence and also caused larval, pupal and adult deformities that confirm the insecticidal activity of the experimental ferns.

Relative toxicity of novel insecticides against Spodoptera litura (Fabricius) field populations

Bioassay studies were conducted to evaluate the insecticides viz. cypermethrin, emamectin benzoate, indoxacarb, lambda-cyhalothrin, malathion, novaluron and thiodicarb by leaf dip method against third instar larvae of Spodoptera litura (Fabricius) field populations. For all the three locations (Berthin, Palampur and Bajaura), the lowest LC50 value was obtained for emamectin benzoate (0.0348 to 0.0715 ppm) followed by indoxacarb (0.2183–0.2714 ppm) and thiodicarb (4.7412–9.5191 ppm). The highest LC50 value was obtained for lambda-cyhalothrin (376.9154 to 517.367 ppm).

Evaluation of Quisqualis indica and Samadera indica Gaertn as botanical pesticides against Spodoptera litura (F.) in Polyhouse

The crude methanol and ethyl acetate extracts of Quisqualis indica L. and Samadera indica Gaetrn. were evaluated for their antifeedant and insecticidal action against third instar larvae of Spodoptera litura (F.) under laboratory condition. Maximum antifeedant activity was observed in crude methanol extracts of S. indica (45.62%) and Q. indica (31.87%) at 5% concentration. Significantly superior insecticidal action (93.51%) was noticed in Q. indica methanol extract 5%, while S. indica methanol extract 5% showed 73.55% larval mortality after three days of exposure. Results of pot culture study conducted under polyhouse revealed that crude methanolic extract of Q. indica and S. indica at 5% reduced the population to less than half with mean population of 3.2 and 3.8 larvae/plant two weeks after spraying. These reveal that these plants could be exploited as botanical pesticides in polyhouse.

Chemical composition, cytotoxicity and insecticidal activities of Acorus calamus accessions from the western Himalayas

Twenty one accessions of Acorus calamus were evaluated for essential oil composition and biological activities during 2009–2014. Essential oil from fresh rhizomes of A. calamus was obtained by hydro–distillation method, and analyzed by GC–FID and GC–MS. The essential oil yield ranged from 1.10±0.28 to 2.50±0.01%. β-asarone, shyobunone and α-asarone were the major constituents in the rhizome oil. Accession IHBT/AC/16 recorded the lowest β-asarone content (31.56%) and IHBT/AC/1 recorded the highest (91.27%). Two accessions, viz., IHBT/AC/7 and IHBT/AC/16, representing triploid and diploid accessions that contain high and low β-asarone content, respectively, were tested for biological activities. The cytotoxicity of these accessions was evaluated against human colorectal adenocarcinoma (HT–29), human epidermoid carcinoma (KB) and human cervical cancer (SiHa) cells at 24, 48 and 72h. Both accessions at 300μg/mL and 72h showed the highest activity against all the tumoral cells. The essential oils of two accessions showed promising larvicidal activities against 2nd instar larvae of Spodoptera litura and Plutella xylostella. However, P. xylostella larvae were more susceptible than the S. litura larvae, and essential oils of accession IHBT/AC/7 were more toxic than accession IHBT/AC/16.

Bioactivity of Sweet Flag (Acorus calamus Linnaeus) Essential Oils against Spodoptera litura Fabricius (Lepidoptera: Noctuidae)

The study aims to determine the chemical compounds, toxicity, and antifeedant activity of sweet flag (Acorus calamus) essential oils against third instar larvae of Spodoptera litura. The study was conducted using a com-pletely randomized design (CRD) using various concentration of the essential oils (103, 2 × 103, 3 × 103, 4 × 103, 5 × 103 ppm). Mortality and antifeedant activity was observed 24 hours after treatment. Toxicity and anti-feedant activity values were 92.5% and 79.3%, respectively, with an LC50 value 586.96 ppm. Gas chromatog-raphy-mass spectrometry analysis showed that essential oil of A. calamus consists of five chemical compounds: methyl isoeugenol, 3.9-decadien-ol-1,3-methyl-6-(1-methylethenyl), 4-pentyl-1-(4propylcyclohexyl)1cyclohexene, γ-asarone and β asarone. Keywords: Acorus calamus , essential oils, mortality, antifeedant, Spodoptera litura The study aims to determine the chemical compounds, toxicity, and antifeedant activity of sweet flag ( Acorus calamus ) essential oils against third instar larvae of Spodoptera litura . The study was conducted using a completely randomized design (CRD) using various concentration of the essential oils (10 3 , 2 × 10 3 , 3 × 10 3 , 4 × 10 3 , 5 × 10 3 ppm). Mortality and antifeedant activity was observed 24 hours after treatment. Toxicity and antifeedant activity values were 92.5% and 79.3%, respectively, with an LC 50 value 586.96 ppm. Gas chromatography-mass spectrometry analysis showed that essential oil of A. calamus consists of five chemical compounds: methyl isoeugenol, 3.9-decadien-ol-1,3-methyl-6-(1-methylethenyl), 4-pentyl-1-(4propylcyclohexyl)1cyclohexene, γ -asarone and β asarone.