Cotton Leafworm Research Articles

Biocidal effect of some quinoa extracts against cotton leafworm insect

Biocidal effect of some quinoa extracts against cotton leafworm insect

Assessment of housekeeping genes stability for gene transcription regulation analysis of Spodoptera littoralis (Lepidoptera: Noctuidae) under Spodoptera littoralis nucleopolyhedrovirus viral infection.

Normalization with respect to stable housekeeping genes is important to facilitate gene transcription regulation research and acquire more accurate quantitative polymerase chain reaction (qPCR) data. In the current study, five candidates housekeeping genes of the cotton leafworm, Spodoptera littoralis encoding for Actin (Actin), elongation factor 1-alpha (EF1α), ribosomal protein S3 (RPS3), ribosomal protein 49 (RP49), and Ubiquitin (Ubi), were evaluated as normalization housekeeping genes under Spodoptera littoralis nucleopolyhedrovirus (SpliNPV) viral infection. The qPCR results confirmed the expression of all five housekeeping genes in S. littoralis viral infected larvae. The expression profiles of the housekeeping genes showed that the EF1α, Actin, and RP49 had the minimum average Ct values of 18.41 ± 0.66, 18.84 ± 0.90 and 19.01 ± 0.87 in all infected samples, respectively. While RPS3 and Ubi showed the maximum average Ct of 21.61 ± 0.51 and 21.11 ± 0.82, respectively. According to the results of ΔCt and geNorm analysis, EF1α was ranked as the most stable housekeeping gene during infection time-course. While by using BestKeeper, geNorm and NormFinder, the Ubi, RP49, and RPS3 showed the most genes transcription stability. The obtained results were also validated using the Cytochrome c oxidase (COX) gene transcripts in response to SpliNPV infection. The results revealed that EF1α and Ubi were the most stable housekeeping genes to be used for normalizing S. littoralis gene transcription regulation under SpliNPV infection. These findings, provide a significant addition for gene transcription regulation studies of S. littoralis upon infection using SpliNPV as a bio-agent.

Impact of mineral paraffin oil as an additive on the efficacy of garlic and ginger essential oils as natural insecticides against cotton leafworm and fall armyworm

Impact of mineral paraffin oil as an additive on the efficacy of garlic and ginger essential oils as natural insecticides against cotton leafworm and fall armyworm

Biological activities of novel 2-pyrazolin-5-one derivatives and their toxicity on certain pests infesting field crops in laboratory conditions

A variety of highly potent derivatives of 2-pyrazoline-5-one, including chromene-3-carbohydrazide 2, 2-thioxothiazole-5-carbohydrazide 3, 2-oxopyridine-3-carbonitriles (4–6), 3-aryl-2-cyanoacrylohydrazide (7, 8), and 3-amino-5-arylpyrazole-4-carbohydrazide (9, 10), were synthesized as pesticide agents using acetohydrazide 1, a versatile and easily obtainable compound. The compounds structures were entirely ascertained utilizing different spectroscopic methods, including Fourier-transform infrared (FTIR), nuclear magnetic resonance spectroscopy, and analysis of elements. In the laboratory, we assessed the impact of nine 2-pyrazoline-5-one derivatives on the fourth larval stage of the cotton leaf worm (Spodoptera littorals), Monacha obstructa, and Tetranychus urticae adults. We used abamectin as the reference compound. The LC50 values of compound 3 for S. littorals, M. obstructa, and T. urticae are 0.90, 0.70, and 0.52 mg a.i./L, respectively. The LC50 values for the same compound for S. littorals, M. obstructa, and T. urticae are 0.80, 0.60, and 0.45 mg a.i./L, respectively. Therefore, it is a remarkably potent compound. Compound 6 exhibited lower levels of danger, as indicated by LC50 values of 1.94, 1.90, and 1.83 mg a.i./L against the three tested pests. Ten days after treatment, all three pests were moderately toxic to the remaining 2-pyrazolin-5-one derivatives, 1, 2, 4, 5, and 7–10. Conversely, the mortality rate of the tested compounds increased when the treated individuals were exposed to high concentrations. These 2-pyrazolin-5-one derivatives are suggested as suitable alternatives and foundational structures for developing novel insecticides.

A short-term impact of enriched CO2 [eCO2] on select growth performance of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) and its host plant Gossypium barbadense L. (Malvaceae)

Natural interactions between herbivorous insect pests and their host plants are expected to be altered significantly as atmospheric CO2 concentrations (aCO2) continue to rise according to climate change scenario. The possible effect of enriched CO2 (eCO2) environments on these interactions is under attention. To better understand such effects on select insect growth parameters; early (3rd) and penultimate (6th) instar larvae of the Cotton Leaf Worm Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae), reared on the cotton plant leaves Gossypium barbadense L. (Malvacae) grown under either ambient (aCO2 = 350 ppm) or enriched (eCO2 = 700 ppm) atmospheres were investigated.

Assessment of bio-efficacy and genotoxicity of commercial insecticides and their nanoemulsion counterparts against cotton leafworm, Spodoptera littoralis

Assessment of bio-efficacy and genotoxicity of commercial insecticides and their nanoemulsion counterparts against cotton leafworm, Spodoptera littoralis

Synthesis, Insecticide Evaluation & Molecular Docking Studies of Some New Functionalized Pyrazole Derivatives Against the Cotton Leafworm, Spodoptera littoralis.

5-(Cyanomethyl)-3-((5,5-dimethyl-3-oxocyclohex-1-en-1-yl)amino)-1H-pyrazole-4-carbonitrile (3) is used as a key for the synthesis of arylidenes 5 a-fvia its reaction with some aldehydes 4 a-f. 5-[(5,5-Dimethyl-3-oxocyclohex-1-en-1-yl)amino]-3-(2-imino-2H-chromen-3-yl)-1H-pyrazole-4-carbonitrile (7) was synthesized via the reaction of compound (3) with 2-Hydroxybenzaldehyde in EtOH/piperidine. The target compounds were tested against cotton leafworm larvae in their second and fourth instar. The available data demonstrated that the LC50 values for commercial phenylpyrazole were 3.37 mg/L and 4.55 mg/L for the most affected synthesized compound, 5 b. The chemical structure of compound 5 bhas two cyano moieties, a pyrazole ring and a chlorophenyl, which may be increasing it efficiency. Evaluation of the latent effects of the examined synthesized compounds on various biological parameters, including adult longevity, pupal weight, proportion of normal, deformed pupae, adult emergency, fecundity, and egg hatchability, was done in an additional effort to slightly improve insecticidal compounds. Seven target synthesized compounds were subjected to a molecular docking analysis against glutamate-activated chloride channels. Twelve artificial compounds with the PDB ID of 4COF were subjected to a molecular docking study against the gamma-aminobutyric acid receptor (GABA).

Biochemical and toxicological effects of certain bioinsecticides on The Egyptian cotton leafworm Spodoptera littoralis

Biochemical and toxicological effects of certain bioinsecticides on The Egyptian cotton leafworm Spodoptera littoralis

Insecticidal Activity of Allium sativum Essential Oil-Based Nanoemulsion against Spodoptera littoralis.

Spodoptera littoralis, commonly known as the Egyptian or African cotton leafworm, is a significant agricultural threat. It is widely distributed in Africa, Mediterranean Europe, and Middle Eastern countries. This polyphagous pest infests numerous crop plants across 44 families, including cotton, soybeans, alfalfa, sweet potato, pepper, eggplant, tomato, maize, lettuce, strawberry, wheat, and hibiscus. The damage caused by S. littoralis on different plant organs, such as young leaves, shoots, stalks, bolls, buds, and fruits, often determines substantial product losses. Current control strategies predominantly rely on synthetic insecticides, which, despite their efficacy, have notable drawbacks, including insecticide resistance, environmental contamination, consumer concerns, and adverse effects on non-target organisms and beneficial insects. In response to these challenges, in this study, we developed and evaluated a garlic EO-based nanoemulsion with a high EO concentration (15%) and low surfactant content to mitigate the possible negative impact on plants and to enhance efficacy against S. littoralis larvae. Laboratory bioassays demonstrated promising larvicidal activity and reduced larval feeding, although some phytotoxicity symptoms were observed. This study underscores the potential of botanical insecticides as sustainable alternatives to synthetic chemicals, emphasizing the importance of balancing efficacy with environmental and ecological considerations in pest management strategies.

Measuring the Flight Trajectory of a Free-Flying Moth on the Basis of Noise-Reduced 3D Point Cloud Time Series Data.

Pest control is crucial in crop production; however, the use of chemical pesticides, the primary method of pest control, poses environmental issues and leads to insecticide resistance in pests. To overcome these issues, laser zapping has been studied as a clean pest control technology against the nocturnal cotton leafworm, Spodoptera litura, which has high fecundity and causes severe damage to various crops. For better sighting during laser zapping, it is important to measure the coordinates and speed of moths under low-light conditions. To achieve this, we developed an automatic detection pipeline based on point cloud time series data from stereoscopic images. We obtained 3D point cloud data from disparity images recorded under infrared and low-light conditions. To identify S. litura, we removed noise from the data using multiple filters and a support vector machine. We then computed the size of the outline box and directional angle of the 3D point cloud time series to determine the noisy point clouds. We visually inspected the flight trajectories and found that the size of the outline box and the movement direction were good indicators of noisy data. After removing noisy data, we obtained 68 flight trajectories, and the average flight speed of free-flying S. litura was 1.81 m/s.

Enhancing toxicity of pyrethroids by oxidase and esterase inhibitors in Spodoptera littoralis (Boisd.) larvae

Although pyrethroids are increasingly being used to control a number of agricultural insect pests, especially the cotton leafworm, Spodoptera littoralis (Boisd.), pyrethroid resistance is a major obstacle limiting effective control. With the aim of maintaining the effectiveness of pyrethroids in managing pests, a study was undertaken to evaluated the effectiveness of oxidase and esterase inhibitors for synergizing pyrethroids in S. littoralis larvae. Compared with the insecticide-susceptible strain (L-SS) of S. littoralis, the resistance ratio (RR) in the field population (F-RS) was 271.43–fold to cypermethrin. The use of profenofos as an esterase inhibitor significantly increased larval susceptibility to cypermethrin in the F-RS strain, with a synergy ratio (SR) of up to 192.57–fold. Significant inhibition of esterase by profenofos in the F-RS strain was found in vivo. Also, piperonyl butoxide (PB) as an oxidase inhibitor had slight effect of cypermethrin toxicity, so its addition is not a solution for pyrethroid resistance. Thus, modifying the toxicity of cypermethrin by mixing it with organophosphorus compounds (OPs) increased its toxicity and decreased the population of S. littoralis, which is a successful strategy for managing pyrethroid resistance.

Evaluation of Novel Soybean Genotypes for Yield, Yield components, Seed Quality and Resistance to Cotton Leafworm

Evaluation of Novel Soybean Genotypes for Yield, Yield components, Seed Quality and Resistance to Cotton Leafworm

New prospective insecticidal agents based on thiazolo[4,5-b]quinoxaline derivatives against cotton leafworm Spodoptera litura (Fabricius): Design, synthesis, toxicological, morphology, histological, and biomedical studies

In this study, a new series of thiazolo[4,5-b]quinoxaline derivatives 3–8 were synthesized by treating 2,3-dichloroquinoxaline with thiosemicarbazone and thiourea derivatives under reflux conditions. The chemical structure of the newly designed derivatives was conducted using spectroscopic techniques. The insecticidal bioassay of the designed derivatives was evaluated against the 2nd and 4th larvae of S. litura after five days as toxicity agents via median lethal concentration (LC50) and the lethal time values (LT50). The results indicated that all the tested compounds had insecticidal effects against both instar larvae of S. litura with variable values. Among them, thiazolo[4,5-b]quinoxaline derivative 3 was the most toxic, with LC50 = 261.88 and 433.68 ppm against 2nd and 4th instar larvae, respectively. Moreover, the thiazolo[4,5-b]quinoxaline derivative 3 required the least time to kill the 50% population (LT50) of 2nd larvae were 20.88, 13.2, and 15.84 hs with 625, 1250, and 2500 ppm, respectively, while for the 4th larval instar were 2.75, 2.08, and 1.76 days with concentrations of 625, 1250, and 2500 ppm, respectively. Larvae's morphological and histological studies for the most active derivative 3 were investigated. According to SEM analysis, the exterior morphology of the cuticle and head capsule was affected. In addition, there were some histological alterations in the cuticle layers and the midgut tissues. Columnar cells began breaking down, and vacuolization occurred in the peritrophic membrane. Moreover, treating 4th S litura larvae hemolymph with compound 3 showed significant changes in biochemical analysis, such as total proteins, GPT, GOT, acetylcholinesterase (AChE), and alkaline phosphatase (AlP). Finally, the toxicity prediction of the most active derivative revealed non-corrosive, non-irritant to the eye, non-respiratory toxicity, non-sensitivity to the skin, non-hepatotoxic, and don't have toxicity on minnow toxicity and T. pyriformis indicating a good toxicity profile for human.

Fabrication and characterization of microemulsion of some insecticides and evaluating their efficacy against cotton leaf worm on cotton crop under laboratory and field conditions

AbstractTraditional pesticide formulations have some shortcomings, including limited efficacy and the usage of huge amounts of insecticide, which has a negative impact on the environment. Using nano‐pesticide formulations reduces the amount of pesticide applied, minimizing pest control expenses and environmental contamination. As a result, this study was conducted to develop a microemulsion formulation containing emamectin benzoate or beta‐cyfluthrin with improved morphology, droplet size, emulsion stability, and persistence of foam. Moreover to assess the efficacy of the developed microemulsion in comparison to the convention alone against the Egyptian cotton leaf worm, Spodoptera littoralis (Boisd.) under both laboratory and field conditions. The results showed that the optimum conditions for emamectin benzoate microemulsion was 2% active ingredient, 5% (w/w) ethyl acetate, and DMF (3:2), 3.5% (w/w) Geronol ff4 and Etocas 35 (6:1), 5% (w/w) ethanol, and 86.5% (w/w) water, while for beta‐cyfluthrin, a 5.0% active ingredient, 15% (w/w) Solvesso 100 and ethyl acetate (2:1), 7.0% (w/w) Geronol ff4 and Etocas 35 (6:1), 10% (w/w) ethanol, and 68% (w/w) water. Under laboratory conditions, emamectin benzoate was more toxic than beta‐cyfluthrin to Spodoptera littoralis second and fourth instar larvae. Emamectin benzoate was more effective that beta‐cyfluthrin against Spodoptera littoralis in the field, whether as a microemulsion or a commercial product. Thus, microemulsions of tested insecticides with better formulation qualities may be more effective than traditional ones in controlling cotton leaf worm.

Fate of synthetic chemicals in the agronomic insect pest Spodoptera littoralis: experimental feeding-contact assay and toxicokinetic model.

Insecticides prevent or reduce insect crop damage, maintaining crop quality and quantity. Physiological traits, such as an insect's feeding behavior, influence the way insecticides are absorbed and processed in the body (toxicokinetics), which can be exploited to improve species selectivity. To fully understand the uptake of insecticides, it is essential to study their total uptake and toxicokinetics independent of their toxic effects on insects. We studied the toxicokinetics (TK) of insecticidally inactive test compounds incorporating agro-like structural motifs in larvae of the Egyptian cotton leafworm (Spodoptera littoralis,Lepidoptera),and their distribution across all biological matrices, using laboratory experiments and modeling. We measured Spodoptera larval behavior and temporal changes of whole-body concentrations of test compounds during feeding on treated soybean leaf disks and throughout a subsequent depuration period. Differences in the distribution of the total quantities of compounds were found between the biological matrices leaf, larva, and feces. Rate constants for uptake and elimination of test compounds were derived by calibrating a toxicokinetic model to the whole-body concentrations. Uptake and elimination rate constants depended on the physicochemical properties of the test compounds. Increasing hydrophobicity increased the bioaccumulation potential of test compounds. Incomplete quantities in larval matrices indicated that some compounds may undergo biotransformation. As fecal excretion was a major elimination pathway, the variable time of release and number of feces pellets led to a high variability in the body burden. We provide quantitative models to predict the toxicokinetics and bioaccumulation potential of inactive insecticide analogs (parent compounds) in Spodoptera.

Biological strategies to control caterpillars in soybean, cotton and maize in the main producing regions of Brazil

Soybean, cotton and maize crops represent some of the main agricultural commodities grown during the hot season in Brazil. In order to provide more effective control options to producers, it is essential to deepen studies on management strategies using biological insecticides. This study aims to evaluate the effectiveness of the application of the bioinsecticide Ocimum basilicum, in controlling the caterpillar complex, notably the looper (Chrysodeixis includens) in soybeans, the fall armyworm (Spodoptera frugiperda) in maize and the cotton leafworm caterpillar (Alabama argillacea) in cotton, as a control alternative aimed at mitigating damage and contributing to more sustainable agricultural practices. Experiments were carried out in each culture in various environments in the states of MT, MS, SP and PR in Brazil. A randomized block design with four replications was used in all the experiments. Agronomic traits, insect pest incidence and insecticide efficiency were evaluated for each of the crops. The data were subjected to after being subjected to stratified analysis of variance for each experimental phase. The interaction significant interactions were broken down to simple effects using Tukey's multiple comparison test of means at 5% probability. Subsequently, Scott-Knott mean grouping was used at 5% probability. Management using 1L per hectare of basil extract (Ocimum basilicum L) demonstrated satisfactory efficacy in controlling the caterpillar complex, approaching the results obtained with traditional chemical control.

Insecticidal effects of the fast pyrolysis bio-oil against Spodoptera littoralis and Aphis gossypii insect pests

The detrimental effects of agricultural pesticides on human and environmental health necessitate the development of alternatives to conventional pesticides. In the laboratory, the cotton leafworm (Spodoptera littoralis) and aphid (Aphis gossypii) insects were used to evaluate the insecticidal activity of bio-oil derived from olive cake. The application of bio-oil by leaf dipping against S. littoralis demonstrated no mortality at a concentration of 1 % bio-oil. In contrast, the bio-oil showed better results against A. gossypii by slide dip method with LC50 = 1310.40 mg/l and LC90 = 3117.40 mg/l. The combined activity of bio-oil and the biopesticide Beauveria bassiana (bio-oil/B.b) was comparable, with LC50 = 1386.94 mg/L and LC90 = 3142.05 mg/L. The field application (two sprays) of bio-oil, bio-oil/B.b, and a commercial insecticide (alpha super) on aphids revealed a reduction of 52 %, 74.33 %, and 74.67 % in the first spray and 59.67 %, 63.33 %, and73.67 % in the second spray for, bio-oil, bio-oil/B.b, and super alpha respectively. The bio-oil and bio-oil/B.b had significantly less effect on the population densities of two predators (predator mite Amblyseius swirskii and aphid lion Chrysoperla carnea) than the insecticide used. Analyses of bio-oil by gaschromatography–mass spectrometry (GC–MS) identified 30 compounds possibly have pesticidal activity. The most abundant compounds are 9 octadecenoicacid methyl ester, hexadecanoic acid, methyl ester, 6 octadecenoic acid, methyl ester and Phenol, 2methoxy. The pyrolysis byproduct (bio-oil) of olive cake biomass contains bioactive compounds that can be used as biopesticide.

Insecticidal and biochemical impacts with molecular docking analysis of three essential oils against Spodoptera littoralis (Lepidoptera: Noctuidae)

As an eco-friendly alternative to chemical insecticides, essential oils (EOs), have gained recognition for their pest-control properties. In this study, the toxicity, biochemical activity and molecular docking analysis of marjoram (Origanum majorana), citronella (Cymbopogon winterianus), and rosemary (Rosmarinus officinalis) EOs were investigated against 2nd instar larvae of cotton leafworm (Spodoptera littoralis) Boisaduval. GC–MS analysis of the chemical composition of the tested EOs showed that O. majorana, C. winterianus, and R. officinalis EOs contained 12, 20, and 5 components, respectively. O. majorana was composed largely of monoterpenoid molecules (47.12%), while both C. winterianus and R. officinalis were composed mainly of monoterpenes (84.39 and 92.16%, respectively). The toxicity tests revealed that R. officinalis EO had the highest insecticidal activity (LC50 = 2526.08 mg/L) against S. littoralis larvae. In addition, the tested EOs resulted in development disruption in S. littoralis, with R. officinalis EO showing the highest potency. Cymbopogon winterianus significantly inhibited the activity of detoxifying enzymes, namely, Carboxylesterase (α- and β-esterase), Glutathione S-Transferase (GST) and Cytochrome P450 (P450s). Similarly, C. winterianus and O. majorana inhibited the activity of superoxide dismutase (SOD). However, no significant difference in CAT activity was observed between the treated larvae and the control. As a result of docking analysis, the interaction of the main constituent of the tested EOs with GST occurred in the following order terpinen-4-ol> (Z)-citral> α-pinene correspondence to their energy score of −4.7386, −4.6491, and −4.5097 kcal/mol, respectively. The obtained results demonstrate the potential use of O. majorana, C. winterianus and R. officinalis EOs in S. littoralis management programs.

Effect of four host plants on the life history and nutritional indices of Spodoptera Littoralis

The Egyptian cotton leafworm Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) is a pervasive and highly polyphagous insect pest. As S. littoralis has developed resistance to major classes of conventional insecticides and the use of these insecticides has caused negative impacts on the ecosystems, it is necessary to search for eco-friendly, cost-effective, and sustainable agents to control. This can be achieved by identifying the preferred host plant. The present study aimed at evaluating the impacts of four host plants– castor bean, tomato, potato, and cucumber on the various life-history traits and nutritional indices of S. littoralis. The concentrations of nitrogen, potassium, and phosphorous in the tested host plants were quantified. Newly hatched larvae were divided into four groups. Each group was fed only on one type of the four tested host plants until pre-pupal stage. Then, the life-history traits and nutritional indices were determined. Larvae fed on castor bean showed the highest adult emergence, weight of full-grown larvae, number of eggs per female, and egg-hatch percent, food consumption, relative growth rate, and food utilization efficiencies. Whereas, larvae fed on cucumber showed the lowest egg-hatch percent, food consumption, relative growth rate, and food utilization efficiencies. There was a positive correlation between nitrogen and phosphorous concentrations in the tested host plants and larval weight, with the highest concentrations in castor bean. Castor bean was the most preferred host plant.

Toxicity and biochemical effects of some insecticides on the cotton leafworm, Spodoptera littoralis(Boisd.) (Lepidoptera: Noctuidae) under laboratory

Toxicity and biochemical effects of some insecticides on the cotton leafworm, Spodoptera littoralis(Boisd.) (Lepidoptera: Noctuidae) under laboratory