منصة إيفاد العلمية

محمد خضر

إرسال رسالة

التخصص: Economic Entomology

الجامعة: Agricultural Research Center

النقاط:

معامل الإنتاج البحثي

الخبرات العلمية

الأبحاث المنشورة

Actinomycetes are a natural resource for sustainable pest control and safeguarding agriculture

المجلة: Archives of Microbiology

سنة النشر: 2024

تاريخ النشر: 2024-01-04

Actinomycetes, a diverse group of bacteria with flamentous growth characteristics, have long captivated researchers and biochemists for their prolifc production of secondary metabolites. Among the myriad roles played by actinomycete secondary metabolites, their historical signifcance in the feld of biocontrol stands out prominently. The fascinating journey begins with the discovery of antibiotics, where renowned compounds like streptomycin, tetracycline, and erythromycin revolutionized medicine and agriculture. The history of biocontrol traces its roots back to the early twentieth century, when scientists recognized the potential of naturally occurring agents to combat pests and diseases. The emergence of synthetic pesticides in the mid-twentieth century temporarily overshadowed interest in biocontrol. However, with growing environmental concerns and the realization of the negative ecological impacts of chemical pesticides, the pendulum swung back towards exploring sustainable alternatives. Beyond their historical role as antibiotics, actinomycete-produced secondary metabolites encompass a rich repertoire with biopesticide potential. The classifcation of these compounds based on chemical structure and mode of action is highlighted, demonstrating their versatility against both plant pathogens and insect pests. Additionally, this review provides in-depth insights into how endophytic actinomycete strains play a pivotal role in biocontrol strategies. Case studies elucidate their efectiveness in inhibiting Spodoptera spp. and nematodes through the production of bioactive compounds. By unraveling the multifunctional roles of endophytic actinomycetes, this review contributes compelling narrative knowledge to the feld of sustainable agriculture, emphasizing the potential of these microbial allies in crafting efective, environmentally friendly biocontrol strategies for combating agricultural pests.

Endophytic actinobacteria from wild medicinal plants are a natural source of insecticide to control the African cotton leafworm (Spodoptera littoralis)

المجلة: AMB Express

سنة النشر: 2023

تاريخ النشر: 2023-01-06

Metabolite profling and in‑silico studies show multiple effects of insecticidal actinobacterium on Spodoptera littoralis

المجلة: Scientific Reports

سنة النشر: 2024

تاريخ النشر: 2024-06-01

The polyphagous pest, Spodoptera littoralis (Boisduval), poses a signifcant global economic threat by gregariously feeding on over a hundred plant species, causing substantial agricultural losses. Addressing this challenge requires ongoing research to identify environmentally safe control agents. This study aimed to elucidate the insecticidal activity of the metabolite (ES2) from a promising endophytic actinobacterium strain, Streptomyces sp. ES2 EMCC2291. We assessed the activity of ES2 against the eggs and fourth‑instar larvae of S. littoralis through spectrophotometric measurements of total soluble protein, α‑ and β‑esterases, polyphenol oxidase (PPO), and catalase enzyme (CAT). The assessments were compared to commercial Biosad® 22.8% SC. Untargeted metabolomics using LC‑QTOF‑MS/MS identifed 83 metabolic compounds as chemical constituents of ES2. The median lethal concentration (LC50) of ES2 (165 mg/mL) for treated Spodoptera littoralis eggs showed signifcant diferences in polyphenol oxidase and catalase enzymatic activities, while the LC50 of ES2 (695 mg/mL) for treated S. littoralis fourth instar larvae showed lower signifcance in α‑ and β‑esterase activities. Molecular docking of ES2 identifed seven potent biocidal compounds, showing strong afnity to PPO and catalase CAT proteins in S. littoralis eggs while displaying limited binding to alpha and beta esterase proteins in the larvae. The results contribute to the understanding of ES2 as a promising alternative biopesticide, providing insights for future research and innovative applications in sustainable pest management strategies.

Changes in Antioxidant Enzymes During the Development of the Cotton Leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

المجلة: Egyptian Academic Journal of Biological Sciences A. Entomology

سنة النشر: 2022

تاريخ النشر: 2022-09-30

Herbivorous insect pests are continuously suffering reactive oxygen species (ROS) from either endogenous or exogenous challenges and they possess an antioxidant system responsible for protecting insect tissues during its development. The present work aims to offer a comprehensive view of antioxidant activity of the destructive pest, the cotton leaf worm, Spodoptera littoralis (Boisd.). The level of four antioxidant enzymes namely, Catalase (CAT), Phenoloxidase (PO), Peroxidase (POX) and Glutathione-S-transferase (GST) have been assessed throughout the insect developmental stages. Generally, the late larval stages hold most of the antioxidant activity in all tested enzymes while the adult showed the least ones. Catalase was completely absent during egg stage while both PO and POX showed a similar trend of activity. The overall results showed a stage-specific antioxidant enzyme activities and we concluded that S. littoralis possess an efficient antioxidant enzyme system which able to withstand oxidative challenges and overcome oxidative stress threat. This study is an essential step in elucidating how antioxidant system develops with age in S. littoralis and eventually how can we make use of these information in future in insect control.

Preliminary Observations And Domestic Management Of The Polyphagous Fall Armyworm, Spodoptera Frugiperda In Sharqia Governorate, Egypt

المجلة: Journal of Agricultural Sciences – Sri Lanka

سنة النشر: 2024

تاريخ النشر: 2024-09-05

Purpose: In mid-2019, fall armyworm, Spodoptera frugiperda (FAW), a highly destructive and polyphagous pest was first discovered in Egypt. It is now a candidate to be a major economic threat to crop production. This study is the first report of this pest at Sharqia Governorate, northern-east Egypt. The available chemical control that is reviewed and reported which is mostly the first assessment in Egypt regarding the extreme shortage in any local data Research Method: Compare the morphological features and description of the detected insect stages with the ideal published data. Through leaf dip bioassay in second instar larvae; the lethal concentrations (LC values) of various conventional and newer insecticides were detected in FAW. Four different insecticides (indoxacarb, methomyl, chlorpyrifos, and metaflumizone were evaluated against both strains (laboratory and field) of FAW. Findings: Generally, the field strain showed resistance to the tested insecticides as compared to the laboratory one; however, indoxacarb (sodium channel blocker) was recorded as the most toxicant one, recording the lowest LC50 and LC90 values (48.79 and 208.47%) for field strain and (16.47 and 103.78%) for laboratory one, respectively. The field strain’s observed insecticide resistance was attributed to resistance mechanisms including a noteworthy rise in the activities of detoxification enzymes. indoxacarb showed the lowest resistance significant values in the field strain as compared to laboratory one. We can conclude that sodium channel blocker i.e. indoxicarb is a promising choice in IPM strategies of FAW in Egypt. Research Limitations: More field studies are required to examine the tested insecticides on different plant species to confirm their effectiveness under field circumstances and to make conclusive recommendations. Originality / Value: Findings can confirm the presence of the invasive FAW in this specific area, register it for the first time, and provide detailed descriptions, also the candidate insecticides proved to be promising control agents to combat FAW larvae under local efforts and domestic circumstances.

Comparative study to determine food consumption of cotton leafworm, Spodoptera littoralis, on some cotton genotypes

المجلة: JOURNAL OF PLANT PROTECTION RESEARCH

سنة النشر: 2015

تاريخ النشر: 2015-06-26

A study was done on the feeding behaviour, development indices, and biochemical response of 4th instar larvae of Spodop- tera littoralis in which seven cotton genotypes were used: Giza86, Giza88, Giza92, 10229 × Giza 86, H10, Suvin, and Karshenseki. Castor bean leaves were used as the control. All the tested cotton genotypes decreased the feeding behavior of S. littoralis larvae in terms of consumption percentages, consumption rate (CR), growth rates (GR), efficiency of conversion of ingested and digested food (ECI and ECD), approximate digestibility (AD), and feeding deterrence (FDI) compared to the control. Additionally, all the tested cotton variet- ies prolonged the time taken for larval and pupal duration and reduced both the pupation percentages and the weight of the resulting pupae, as compared to the control. Giza86 recorded the lowest values of both larval growth index and fitness (7.31 and 1.05, respec- tively) while the genotype Suvin recorded the lowest standardised growth index (0.020) more than other genotypes and the control that gave 10.16, 1.53, and 0.032, respectively. There was a significant inhibition in the level of both total soluble protein and total lipids, and activities of amylase and the trehalase enzymes in all the tested varieties, compared to that found in the control.

Ovicidal activity of Sesamum indicum (L.) oil against Spodoptera littoralis (Boisd.)

المجلة: Archives of Phytopathology and Plant Protection

سنة النشر: 2016

تاريخ النشر: 2016-04-12

n the research for alternative tools and botanical products to control Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae). Sesamum indicum (L.) (Lamiales: Pedaliaceae) oil was assayed as an ovicide. The mortality increased with existence of fatty acids. Chemical analysis of S. indicum oil using GLC analysis showed palmitic acid as the major fatty acid (51.27%), while the major hydrocarbon and sterols were found to be heneicosane (58.63%) and β-sitosterol (2.60%), respectively. Generally, the values of LC50s indicated that one- day-old egg masses are more susceptible than three-day-old eggs. Also, the leaf dip technique is more efficient than the spraying one. Results showed several features of chorionic surface deformation treated with sesame and KZ oils than control using scanning electron microscopy. Meanwhile, the tested oils caused significant reduction in both total soluble protein and transaminase enzymes as compared to control. Additionally, the oils elongated the incubation period and larval duration than control.

ULTRASTRUCTURE AND BIOCHEMICAL ALTERATIONS OF COTTON LEAFWORM, SPODOPTERA LITTORALIS TREATED WITH IPOMEA CARNEA EXTRACT

المجلة: Egyptian Journal of Agricultural Research.

سنة النشر: 2015

تاريخ النشر: 2015-06-01

Abstract Ipomea carnea (Jacq.) is a wild grown and distributed plant in the Egyptian environment on banks and borders of streams and water courses along Nile river region. This study designed to evaluate the ultrastructural and biochemical changes in 4th larval instar of cotton leafworm as a result of application with the acetonic extract of this plant compared to traditional insecticide (chlorpyrifos). According to LC50 and LC90 values chlorpyrifos was the most effective that recorded (9.497 and 91.126 ppm, respectively), followed by acetonic extract of I. carnea (24.622 and 164.947ppm.), respectively. Many ultrastructure changes in the treated larvae mid gut epithelial cells were recorded using LC50 of both tested treatments. These changes like nucleus elongation, strong agglomeration of chromatin, extreme dilation of endoplasmic reticulum, destruction of microvilli where apical cytoplasm was vesiculated. In addition, enormous changes in the structure of cuticle such as being edges and separation of endocuticle from epicuticle were also observed.Results showed that, I. carnea at LC25 and positive control (using acetone only) insignificant decrease the total soluble protein in the supernatant of the homogenated larvae than negative control (using water only). Whereas, I. carnea and chlorpyrifos at (LC50) significantly increased the effect of total soluble protein than control. Additionally, all the treatments increased activities of AST and ALT in the supernatant of S. littoralis compared to negative control. I

Performance of the Aphid Parasitoid, Diaeretiella rapae (M’Intosh) towards Certain Aphid Species in Egypt

المجلة: Journal of Entomology

سنة النشر: 2014

تاريخ النشر: 2014-08-01

Survey and population of the aphid species Brevicoryne brassicae L., Aphis craccivora (Koch), Aphis nerii Boyer de Fonscolombe., Hyalopterus pruni (Geoffroy) and Hypermoyzus lactucae L. and its parasitoids were studied at Kafr Saqr district during two successive seasons 2011-2013. Obtained results and showed that Diaeretiella rapae (M’Intosh) was the dominant on aphid species in this study, where it occupied 81.79, 55.25, 51.20, 54.95% and 86.94, 63.77, 52.61, 52.53% on aphid species, B. brassicae, A. craccivora, A. nerii and H. pruni during the two seasons, respectively. The mean percentages of parasitism were 39.32, 9.14, 16.08, 4.66 and 43.45, 8.68, 13.22, 5.37 on the same aphid species on cabbage, faba bean, dafla and reed plants in both seasons, respectively. Total developmental times (Sting-Adult) were 15.58±0.69, 12.17±0.75, 17.52±0.70 and 15.37±0.71 days. Sex ratio were (Female:Male) 1.2:1, 1.07:1, 1.014:1 and 1:1.09 on last aphid species, respectively during the two seasons. A significant positive relationship was found between higher parasitism percentages of D. rapae and higher nutrient composition of both total lipids and free amino acids in tested aphids.

Control of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) and Tetranychus urticae (Acari: Tetranychidae) by Coriander Essential Oil

المجلة: Journal of Entomology

سنة النشر: 2013

تاريخ النشر: 2013-09-01

This study was carried out to evaluate bioactivity of essential oil of Corianderum sativum L. on egg stage of some cotton pests in Egypt, i. e. Spodoptera littoralis (Boisd.) and Tetranychus urticae Koch. The chemical constitution of the essential oil of coriander, that collected from Egypt were determined by GC-MS analysis, linalool and α-pinene were the basic constituents in the essential oil that recorded (64.103 and 11.964%).The ovicidal activity of obtained oil indicated that according to LC50 values, the younger one day-old eggs of both S. littoralis and T. urticae are more susceptible to coriander essential oil than older ones (three days-old) recording (0.055 & 1.565%), and (1.489 and 4.759 %), respectively. Latent effect with LC50 of coriander essential oil on the successive stages of both S. littoralis and T. urticae resulted from treated eggs were also detected. The larval mortality of S. littoralis recorded 20.00 and 16.00 %, respectively in return to zero % for controls. Furthermore, biological parameters was affected due to essential oil treatment that both larval and pupal duration as well as incubation period elongated compared to control while the reverse was true in case of pupation and pupal weight which reduced due to treatment. As for, biological aspects of T. urticae, caused shortest incubation period of both tested egg- ages comparing to its control, treated 24 hrs old eggs caused elongation in longevity and life span of female compared to control, in both treated tested egg-ages. Finally results demonstrated that, highly significant reduction in the total number of eggs laid per female (fecundity) for 24 hrs old eggs was recorded 60.067 eggs/female, control gave 87.00±6.93 eggs. Insignificant reduction was detected as affected by treated 72 hrs old eggs laid 114 eggs, control laid 117 eggs.

The potential of cinnamon, Cinnamomum zeylanicum essential oil as a natural ovicide against cotton leafworm, Spodoptera littoralis

المجلة: Thai Journal Agricultural Sciences

سنة النشر: 2020

تاريخ النشر: 2020-08-01

The present work deals with the extraction of volatile oil from dried bark of Cinnamomum zeylanicum. The volatile oil was extracted by the common hydro distillation method and determined by GC–MS. A total of 12 components were identifed. The major component in the essential oil was the aromatic compound E, Z–cinnamaldehyde (31.91%), followed by the main groups, monoterpenoids or oxygenated monoterpenes (27.25%), sesquiterpene hydrocarbons (15.29%) and sesquiterpenoids (10.69%). The essential oil possessed ovicidal activity against three-day old eggs of Spodoptera littoralis (Boisduval) with LC50 and LC90 values of 1.64 and 7.42%, respectively. Dipping eggs in LC50 values might be indicated the presence of abnormalities in the external morphology of eggshell, chorion surface and micropyle area as compared to untreated eggs using a scanning electron microscope. Additionally, the tested oil signifcantly reduced total soluble protein, total lipids and activities of both acid phosphatase and phenoloxidase enzymes as compared to control. Moreover, the oil afected some biological parameters such as incubation period of the eggs and subsequent ofspring, i.e., larval mortality, larval and pupal duration and pupal weight compared to the control. This information might help in developing IPM strategies against this serious pest

PERFORMANCE OF CERTAIN INSECT GROWTH REGULATORS ON COTTON LEAF WORM, SUCKING PESTS AND THEIR IMPACTS ON COMMON PREDATORS IN EGYPTIAN COTTON FIELDS

المجلة: Pakistan Entomologist

سنة النشر: 2019

تاريخ النشر: 2019-10-26

Field experiments were carried out to study the effect of four insect growth regulators belonging to two major groups: chitin synthesis inhibitors (CSIs); lufenuron and teflubenzuron and non-steroidal ecdysteroid agonists (NEAs); methoxyfenozide and chromafenozide compared to two traditional insecticides; chlorfenapyr and profenofos against and the cotton leafworm, Spodoptera littoralis (Boisd.) and sucking pests: Bemisia tabaci (Genn.), Empoasca spp. and Tetranychus urticae Koch. Furthermore, their impact on common predators which exists in Egyptian cotton fields during 2017 and 2018 seasons. Results revealed that lufenuron proved to be highly effective against all tested pests with special regard to S. littoralis that showed highly significant initial and residual reduction compared to other pesticides (98.18±0.69 and 97.75±0.87%) and (98.83±0.56 and 98.25±0.54) in 2017 and 2018, respectively. Generally, all the tested IGRs showed moderate to low reduction percentages for B. tabaci, Emposca spp. and T. urticae in both initial and residual effects, respectively. On the other hand, profenofos was found most toxic and significantly reduced the predator's population recorded 62.83±0.81 & 38.15±0.73% in 2017 and 60.56±1.03 & 34.88±0.53% in 2018 in the initial and residual reduction, respectively, followed descendingly by chlorfenapyr and finally the tested IGRs. Both Orius spp. and spiders were more susceptible than other predators towards all pesticides used.