Spodoptera Littoralis Research Articles

Effect of herbivore stress on transgene behaviour in maize crosses with different genetic backgrounds: cry1Ab transgene transcription, insecticidal protein expression and bioactivity against insect pests

BackgroundDecades after their first commercial release, many theoretical assumptions are still taken for granted in the deployment of genetically modified (GM) crops. Theoretically, in the case of maize, active transcription of the cry1Ab transgene would result in dose-dependent production of the insecticidal Cry1Ab protein, which would in turn induce dose-dependent mortality on lepidopteran pests. We produced data to realistically approach this question by using a model that includes two genetic background contexts from two geographical provenances in Brazil and South Africa, and two lepidopteran pests (Helicoverpa armigera and Spodoptera littoralis). However, in this study, the effect of insect herbivory was superimposed to investigate possible stress-induced effects in transgene expression at three levels: mRNA, protein and bioactivity.ResultsOverall, we found that herbivore damage by H. armigera was reflected only at the translational level, with a higher level of Cry1Ab protein measured in the Brazilian crosses under herbivore stress. On the other hand, compared to non-stress growing conditions, the herbivore damage by S. littoralis was not directly reflected in mRNA, protein or bioactivity in the South African crosses.ConclusionsThe differences between South African and Brazilian genetic backgrounds, and between the stressor effect of the two herbivores used, highlight the complexity of transgene expression at the agroecological level.

Vegetable waste extracts as enhancers of baculovirus infections

Vegetable waste extracts (VWE) contain a great variety of antioxidants such as polyphenols, which have shown to potentiate baculovirus infections, making them ingredients for pest control ingredients. In the present study, the mortality enhancement of different vegetable extracts obtained from food residues when combined with baculoviruses was evaluated. Extracts from spent coffee (E2), rosehip (E17), asparagus (E28), artichoke (E29), beet stalks (E32) and banana peel (E37) were selected as they increased mortality of Spodoptera littoralis nucleopolyhedrovirus (SpliNPV) in second instar S. littoralis larvae, when comparing with the virus inoculation alone. Extracts were assayed at 1 % w/v. In S. littoralis-SpliNPV system, the selected extracts reduced the median lethal concentration (LC50) of SpliNPV against second instar larvae. The E37 extract presented the highest potentiation, as it reduced the LC50 13.61 times, while the rest of the extracts presented LC50 reductions from 3.71 to 7.72-fold. In Spodoptera exigua-SeMNPV (Spodoptera exigua multiple nucleopolyhedrovirus) system, none of the extracts decreased the LC50 of SeMNPV. In contrast, in Spodoptera frugiperda-SfMNPV (Spodoptera frugiperda multiple nucleopolyhedrovirus) system, E2 showed the greatest potentiating effect. In the heterologous systems, none of the extracts tested increased the effective host range of SfMNPV, AcMNPV (Autographa californica multiple nucleopolyhedrovirus), and MbMNPV (Mamestra brassicae multiple nucleopolyhedrovirus) in second instar S. littoralis larvae. Thus, the viral enhancing effect of VWE was host-pathogen and instar dependent. However, the potentiation effect of the extracts could not be directly related with the antioxidants content of the extracts.

Acaricidal and insecticidal activity of essential oils obtained from the aerial parts of three Mexican Bursera species

In search of new sustainable biopesticides, we determined the phytochemical profiles, acaricidal and insecticidal properties of EOs distilled from the aerial parts of three Mexican Bursera species. Results were obtained by GC–MS analysis and three different bioassays, indicating that the EO of Bursera glabrifolia exhibited high relative abundancies of α-pinene, β-myrcene, and α-phellandrene, as well as promising pesticidal activity against Spodoptera littoralis larvae (LD50,90 = 32.4, 107.2 µg/larva), and Musca domestica (LD50,90 = 23.2, 103.2, and 13.5, 77.4 µg/female or male adult, respectively) and Tetranychus urticae adults (LD50,90 = 7.4, 30.3 µg/cm2). The Bursera lancifolia and Bursera linanoe samples contained mainly D-limonene or linalyl acetate and linalool, respectively, and showed generally less potent pesticidal properties (S. littoralis larva, LD50,90 = 45.4, 154.4 and 52.2, 158.7 µg/larva, respectively; female M. domestica adult, LD50,90 = 69.2, 210.9 and 45.1, 243.8 µg/female adult, respectively; T. urticae adults, LD50,90 = 20.7, 90.5 and 17.5, 71.4 µg/cm2, respectively). However, the EO of B. linanoe exhibited an especially pronounced activity against male M. domestica adults (LD50,90 = 10.6, 77.2 µg/male adult). Our findings prove the pesticidal potential of Mexican Bursera species in the context of integrated pest management (IPM) and highlight the importance of conducting further research to elucidate both the active principles and possibly existing synergistic effects.

Synthesis of Tungsten Oxide, Iron Oxide, and Copper-Doped Iron Oxide Nanocomposites and Evaluation of Their Mixing Effects with Cyromazine against Spodoptera littoralis (Boisduval).

Nanotechnology research is emerging as a cutting-edge technology, and nanocomposites have played a significant role in pest control. Therefore, the present study focuses on the synthesis of tungsten oxide (WO3), iron oxide (magnetic nanoparticle, MNP), and copper-doped iron oxide (MNP-Cu) nanocomposites and explores the different effects of their binary combinations with the insecticide cyromazine against Spodoptera littoralis. The synthesized nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and Raman spectroscopy. None of the tested nanomaterials showed any toxicity against the different stages of S. littoralis. Larval and pupal durations increased with increasing cyromazine and nanomaterial concentrations. The longest larval and pupal durations were recorded under treatment with the mixture of cyromazine (100 mg/L) + MNP-Cu (500 mg/L); the survival periods were 23.5 and 15.6 days, compared with 10.8 and 7.7 days in the control, respectively. The percentages of pupation and adult emergence were negatively affected by all treatments. Among the 500 mg/L nanomaterial combinations, only cyromazine (25 mg/L) and WO3 (500 mg/L) resulted in adult emergence (at a rate of 27.3%). Some abnormalities in the S. littoralis stages were observed following treatment with the tested materials. The glutathione S-transferase and alpha-esterase enzyme activities in S. littoralis were significantly increased after treatment with cyromazine, followed by cyromazine/MNP-Cu combinations. The quantitative polymerase chain reaction (Q-PCR) data showed that all treated insects had a higher immune response than the control. Finally, mixes of nanocomposites and cyromazine may be suggested as viable alternatives for S. littoralis management.

Moringa oleifera and Ruta angustifolia fixed oils and a prospective method to obstruct pupal development in cotton leafworm

The cotton leafworm, Spodoptera littoralis, is a polyphagous pest that attacks various economic crops. Integrated Pest Management (IPM) uses different techniques to combat this pest unfortunately chemical control is the predominant. However, it does not target the pupal stage of the insect. Therefore, a safe and cost-effective technique must be developed to address this issue.This technique integrates using plant-based agents; M. oleifera and R. angustifolia seed oils as pupaicids. Various concentrations (1%, 2%, and 4%) of both oils were employed by means of the dipping method of pre-pupae. The study delved into the biological, and biochemical aspects of pupal development to adult emergence. Analysis of the fatty acids along with the hydrocarbons and sterols was conducted through GLC analysis for oils composition.Our research has shown that Moringa oleifera and Ruta angustifolia oils at a concentration of 4 % have a significant impact on pre-pupal mortality (42.57& 61.9 %) and pupation of survival pre-pupa (57.42&38.09 %) However, emerged adults were reduced to 83.33 % and 60 %, respectively. Chitinase recording significantly disturbance after 1 day for Ruta (6.21 µg/min/g) and Moringa oil (2.12 µg/min/g). Also, Phosphatase enzyme showed a significant disturbance after 4 and 7 days of treatments. GLC data of fatty acids showed that oleic acid (74.42 %) was the major fatty acid in M. oleifera oil, while linolenic, linoleic, and oleic acids represented 31.39 %, 22.70 %, and 21.95 %, respectively, in R. angustifolia oil. Sterols in M. oleifera oil were β-sitosterol and stigmasterol, while Ruta oil contained additional amounts of cholesterol and campesterol,Briefly, the suggested technique was effective in disturbing pupal development and reducing emerged adults. Ruta was more effective than Moringa oil due to its contents of sterols and hydrocarbons that may affect ecdysis.

Fatty alcohols, a minor component of the tree tobacco surface wax, are associated with defence against caterpillar herbivory.

Despite decades of research resulting in a comprehensive understanding of epicuticular wax metabolism, the function of these almost ubiquitous metabolites in plant-herbivore interactions remains unresolved. In this study, we examined the effects of CRISPR-induced knockout mutations in four Nicotiana glauca (tree tobacco) wax metabolism genes. These mutations cause a wide range of changes in epicuticular wax composition, leading to altered interactions with insects and snails. Three interaction classes were examined: chewing herbivory by seven caterpillars and one snail species, phloem feeding by Myzus persicae (green peach aphid) and oviposition by Bemisia tabaci (whitefly). Although total wax load and alkane abundance did not affect caterpillar growth, a correlation across species, showed that fatty alcohols, a minor component of N. glauca surface waxes, negatively affected the growth of both a generalist caterpillar (Spodoptera littoralis) and a tobacco-feeding specialist (Manduca sexta). This negative correlation was overshadowed by the stronger effect of anabasine, a nicotine isomer, and was apparent when fatty alcohols were added to an artificial lepidopteran diet. By contrast, snails fed more on waxy leaves. Aphid reproduction and feeding activity were unaffected by wax composition but were potentially affected by altered cutin composition. Wax crystal morphology could explain the preference of B. tabaci to lay eggs on waxy wild-type plants relative to both alkane and fatty alcohol-deficient mutants. Together, our results suggest that the varied responses among herbivore classes and species are likely to be a consequence of the co-evolution that shaped the specific effects of different surface wax components in plant-herbivore interactions.

Green synthesis, biological and molecular docking of some novel sulfonamide thiadiazole derivatives as potential insecticidal against Spodoptera littoralis

Although crop plants provide the majority of human food, pests and insects frequently cause huge economic losses. In order to develop innovative insecticidal compounds with low toxicity and a positive environmental impact, we developed new N-(4-sulfamoylphenyl)-1,3,4-thiadiazole-2-carboxamide derivatives (2–12). With the use of spectroscopic techniques and elemental data, the chemical structure of these new compounds was meticulously clarified. The toxicological and biological effects of the synthesized compound of the cotton leafworm Spodoptera littoralis (Boisduval, 1833) under laboratory conditions were also investigated. Regarding the determined LC50 values, compounds 3, 7, 8, and 10 showed the most potent toxic effect with LC50 values of 29.60, 30.06, 27.65 and 29.01 ppm, respectively. A molecular docking investigation of twelve synthetic compounds (from compound 2 to compound 12) was performed against AChE (Acetylcholinesterase). There was a wide range of binding affinities shown by these compounds. This work suggests that these substances may have insecticidal and AChE inhibitory properties, and it may be possible to further explore them in the process of creating pesticides that target AChE.

High-efficiency removal of pyrethroids using a redesigned odorant binding protein

Pyrethroids are ubiquitously present in environmental media and threaten both the ecosystem and human health. To explore effective ways to remove pyrethroids from the environment, an odorant binding protein (OBP) with affinity for various pyrethroids was investigated. Initially, the target OBP, Spodoptera littoralis pheromone binding protein 1 (SlitPBP1), underwent redesign to enhance its affinity for pyrethroids. The modified SlitPBP1E97ND106E demonstrated a substantially increased affinity for deltamethrin (DeltaM), with a dissociation constant of 0.77 ± 0.17 μM. The affinity of SlitPBP1E97ND106E for other pyrethroids also increased to varying extents. Consequently, SlitPBP1E97ND106E displayed a markedly enhanced capability to adsorb and remove pyrethroids. When exposed to free SlitPBP1E97ND106E in solution, the reduction in DeltaM surged from 16.78 ± 0.32% to 97.51 ± 0.56%. SlitPBP1E97ND106E was immobilized by coupling the protein to Ni2+-NTA agarose resin. Liquid chromatography results attested to the superior efficacy of immobilized SlitPBP1E97ND106E in removing pyrethroids, especially DeltaM. No significant differences in pyrethroid removal were detected across various water samples. Our findings introduce a potent tool for pyrethroid removal. A wider range of OBPs can similarly be optimized and applied to remove organic pollutants, including but not limited to pesticides.

Synthesis of inventive biphenyl and azabiphenyl derivatives as potential insecticidal agents against the cotton leafworm, Spodoptera littoralis

The emergence of pest resistance of Spodoptera littoralis (order; Lepidoptera, family; Noctuidae) towards the large scale of different classes of insecticides necessitates the development of some new poly-functionalized biphenyl and azabiphenyl with highly anticipated insecticidal bioresponse. Four new biphenyl carboxamidines 4a–d and four aza-analogue picolinamidine derivatives 8a–d were designed and prepared via the treatment of their corresponding carbonitriles with lithium-bis trimethylsilylamide [LiN(TMS)2], followed by hydrolysis with hydrogen chloride. Furthermore, these compounds were elucidated by spectral data, and their toxicity and insecticidal activity were screened against Spodoptera littoralis. Whereby, toxicological and biochemical aspects of the inventively synthesized biphenyl and azabiphenyl derivatives against the cotton leafworm, Spodoptera littoralis were inspected. As regards the indomitable LC50 and LC90 values, biphenyl and aza-analogues 8d, 8a, 4b, and 8b, revealed the furthermost forceful toxic effects with LC50 values of 113.860, 146.265, 216.624, and 289.879 ppm, respectively. Whereby, their LC90 values are 1235.108, 1679.044, 2656.296, and 3381.256 ppm, respectively, and toxicity index being 22.31%, 17.36%, 11.72%, and 8.76%, respectively, comparing with the already recommended, methomyl insecticide, lannate 90% SP (LC50, 25.396 and LC90, 57.860 and toxicity index, 100%). Additionally, electrochemical parameters via DFT studies were carried out for demonstrating and elucidation of structure–activity relationship (SAR) according to highly motived compounds, descriptors, and the in vivo insecticidal activities.Graphical

Biogenic Selenium Nanoparticles: Anticancer, Antimicrobial, Insecticidal Properties and Their Impact on Soybean (Glycine max L.) Seed Germination and Seedling Growth.

Selenium nanoparticles (SeNPs) have demonstrated significant potential in a variety of disciplines, making them an extremely desirable subject of research. This study investigated the anticancer and antibacterial properties of my-co-fabricated selenium SeNPs, as well as their effects on soybean (Glycine max L.) seeds, seedling growth, cotton leafworm (Spodoptera littoralis) combat, and plant pathogenic fungi inhibition. SeNPs showed anticancer activity with an IC50 value of 1.95 µg/mL against MCF-7 breast adenocarcinoma cells. The myco-synthesized SeNPs exhibited an antibacterial effect against Proteus mirabilis and Klebsiella pneumoniae at 20 mg/mL. The use of 1 µM SeNPs improved soybean seed germination (93%), germination energy (76.5%), germination rate (19.0), and mean germination time (4.3 days). At 0.5 and 1.0 µM SeNPs, the growth parameters of seedlings improved. SeNPs increased the 4th instar larval mortality of cotton leafworm compared to control, with a median lethal concentration of 23.08 mg/mL. They inhibited the growth of Fusarium oxysporum, Rhizoctonia solani, and Fusarium solani. These findings demonstrate that biogenic SeNPs represent a promising approach to achieving sustainable progress in the fields of agriculture, cancer therapy, and infection control.

Performance of some new soybean genotypes against the infestation of the cotton leaf worm, Spodoptera littoralis Boisd

Cotton leaf worm, Spodoptera littoralis (Lepidoptra: Noctuidae) is considered one of the most destructive insect pests in Egypt. A field trail was conducted at the experimental farm of Nubaria agricultural research station, Behaira Governorate, Egypt, during 2021 and 2022 seasons to evaluate the performance of 14 new genotypes and two check varieties under the cotton leaf worn natural infestation conditions. The experimental design was a randomized complete block design (RCBD) with three replicates. The combined results revealed that there were substantial differences across genotypes for all evaluated parameters. The genotypes (H7L39/2015, H6L49, and H6L28) were considered as more resistant ones over the resistant check variety (Giza 111) which recorded the least infestation (25.86, 27.57 and 32.14 %, respectively), with feeding damage area of 18.52, 19.58 and 18.58 %, respectively. These genotypes gave the highest leaf content of P%, K%, total phenolic compounds, yield, and its components. The correlations between infestation% and leaflet area damage% or N all were positive on one another. All other correlations, with the exception of plant height and branches no plant-1, had negative effects on one another. The results proposed that the genotypes (H7L39/2015, H6L49 and H6L28) are promising and could be planted at Nubaria region and used in the breeding programs.

Modeling the potential global distribution of the Egyptian cotton leafworm, Spodoptera littoralis under climate change

The Egyptian cotton leafworm, Spodoptera littoralis is a highly invasive insect pest that causes extensive damage to many of the primary food crops. Considering the recent challenges facing global food production including climate change, knowledge about the invasive potential of this pest is essential. In this study, the maximum entropy model (MaxEnt) was used to predict the current global spatial distribution of the pest and the future distribution using two representative concentration pathways (RCPs) 2.6 and 8.5 in 2050 and 2070. High AUC and TSS values indicated model accuracy and high performance. Response curves showed that the optimal temperature for the S.littoralis is between 10 and 28 °C. The pest is currently found in Africa and is widely distributed across the Middle East and throughout Southern Europe. MaxEnt results revealed that the insect will shift towards Northern Europe and the Americas. Further, China was seen to have a suitable climate. We also extrapolated the impact of these results on major producing countries and how this affects trade flow, which help decision makers to take the invasiveness of such destructive pest into their account.

Synthesis and Physico-chemical Properties of some New Surface Active Agents and their Improvement Effects on Emamectin benzoate against Spodoptera littoralis

Synthesis and Physico-chemical Properties of some New Surface Active Agents and their Improvement Effects on Emamectin benzoate against Spodoptera littoralis

Old and new association of Cotesia icipe (Hymenoptera: Braconidae) with alien invasive and native Spodoptera species and key stemborer species: Implication for their management.

The production of maize in Africa is hindered by a myriad of biotic challenges, key among them being invasive and native lepidopteran stemborers. The recent invasion of the continent by Fall armyworm, Spodoptera frugiperda has further exacerbated the situation. Fortunately, Cotesia icipe was found to be very promising against S. frugiperda. However, the co-occurrence and interaction between S. frugiperda and the stemborers (Busseola fusca, Sesamia calamistis, and Chilo partellus) in maize agroecosystem may jeopardize the efficiency of C. icipe as a biocontrol agent of S. frugiperda. This study investigated the performance of C. icipe on S. frugiperda, Spodoptera littoralis and the stemborers. Specifically, the preference and acceptability of C. icipe to the host insects; physiological suitability of the hosts for its development, and effect of these hosts on fitness parameters of the offspring were assessed. Cotesia icipe accepted all the tested hosts albeit with higher preference to the Spodoptera species than stemborers under multiple choice tests. Also, the highest parasitism of up to 97% was recorded on S. frugiperda compared to that on the stemborers of 43% in B. fusca. Moreover, physiological suitability and fitness traits (except for percent female offspring) varied with host species, again being optimal on the Spodoptera species. Cotesia icipe demonstrated strong potential to control S. frugiperda in maize due to its high affinity for parasitisation and developmental success in this host; and despite its non-specific parasitisation, the presence of other hosts may not prevent its maximum control of S. frugiperda. This article is protected by copyright. All rights reserved.

Evaluation of chlorpyrifos and Beauveria bassiana as a strategy in the Egyptian sugar beet fields: impact on Spodoptera littoralis (Boisduval) and its associated predators populations and the sugar beetroot yield

BackgroundThe susceptibility of pests and natural enemies to conventional insecticides is a critical element in judging the success of integrated pest management programs implementing biological control as a tactic. In this study, the susceptibility of the cotton leafworm Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) to an organophosphorus insecticide (chlorpyrifos) and the entomopathogenic fungus Beauveria bassiana was evaluated through field applications during two successive sugar beet seasons. The populations of the coccinellid, chrysopid, and formicid predators were estimated to indicate pesticide risk assessment strategy. The root and sugar yields were compared during the whole experiment to emphasize the impact of both control strategies on the pre-harvest loss in this strategic crop.ResultsResults indicated that over the course of the two seasons of the investigation, chlorpyrifos significantly reduced the population density of S. littoralis and its associated predators. It showed a detrimental effect on S. littoralis larval population than untreated areas, causing an overall reduction of 97 and 92% during the 1st and 2nd seasons, respectively. The biopesticide based on entomopathogenic fungus Beauveria bassiana caused an overall reduction of S. littoralis, reaching 96 and 65% during the 1st and 2nd seasons, respectively. Meanwhile, B. bassiana slightly affects the population of predators compared to insecticide-free areas, so it was recommended for application in sugar beet fields without providing considerable risk to the associated insect predators. The sugar beetroot production and its sugar content increased significantly in both treatments during the two growing seasons compared to non-treated plots.ConclusionChlorpyrifos is not recommended for pest control; instead, B. bassiana is considered an effective biopesticide in the Egyptian sugar beet fields infested with S. littoralis as part of an integrated pest management program. Their effect was direct through reducing pest population and indirectly increasing the sugar beetroot production and increasing its total sugar content. Hence, both the sugar beetroot quality and quantity were improved favoring the microbial agent over the chemical insecticide in application for mitigating the chemical hazards toward the associated predators.

Endophytic colonization of sugar beet by Beauveria varroae and Beauveria bassiana reduces performance and host preference in army worm, Spodoptera littoralis

Spodoptera littoralis (Lepidoptera: Noctuidae) Boisduval 1833 is a voracious leaf feeder and major agricultural pest attacking numerous crops. Development of insecticide resistance hampers management efforts for S. littoralis and entomopathogenic fungi represent one possible alternative management tool. Here, we quantified colonization of sugar beet, Beta vulgaris L, with two fungal entomopathogens, Beauveria varroae Vuillemin 1912 and Beauveria bassiana (Balsamo) Vuillemin 1912 (Ascomycota: Hypocreales), and examined their endophytic effects on biological and reproductive parameters of S. littoralis. Two methods were used to inoculate sugar beet: soaking seeds in spore suspension and spray application of conidia onto leaves. For both methods, fungal suspensions with concentrations of 1 × 104 and 1 × 108 conidia/ml colonized roots, stems, and leaves of sugar beet. The colonization rate increased over time. Following inoculation of seeds, weight gain of S. littoralis larvae fed on leaves infected with endophytic fungi was reduced compared with controls. Furthermore, protease and lipase activities in the gut of S. littoralis decreased with increasing concentration of fungus applied to plants. An increase in phenol oxidase activity in the gut also indicated increased defense response of larvae feeding on Beauveria-infected leaves. Both B. bassiana and B. varroae decreased the duration of larval and pupal stages, adult emergence, and oviposition by females. Incubation of sugar beet seeds with B. varroae or B. bassiana decreased survival of pupae and egg laying by female moths on endophyte-infested treatments by 30 and 50%, respectively, compared with controls. Furthermore, an initially female biased sex ratio decreased toward 50:50 over time in populations of S. littoralis reared on sugar beet colonized by fungal endophytes as compared with controls, which remained female-biased. Endophyte inoculation increased growth of sugar beet compared with controls. Our results indicate that B. bassiana and B. varroae affect survival of S. littoralis and may be useful for management of this pest.

Two Novel Iboga-Type and an Oxindole Glucuronide Alkaloid from Tabernaemontana peduncularis Disclose Related Biosynthetic Pathways to Tabernaemontana divaricata.

Phytochemical investigation of the two Tabernaemontana species (Apocynaceae) T. peduncularis Wall. and T. divaricata (L.) R.Br. ex Roem. & Schult. indicated closely related biosynthetic pathways leading to lipophilic and hydrophilic alkaloids. In total, 18 specialized metabolites comprising indole-derived alkaloid aglycones, three oxindole-derived alkaloid glycosides, and two iridoid glucosides could be identified in the studied species. Among the alkaloids, the two Iboga-type alkaloids 3,7-coronaridine isoindolenine, coronaridine 3,4-iminium and a javaniside derivative bearing a glucuronic acid, named javanuronic acid, could be described by spectroscopic and spectrometric methods for the first time. A docking experiment using alpha-fold was performed to generate a protein model of the enzyme 7-deoxyloganetic acid glucosyl transferase. Performed bioassays exhibited a growth reduction of neonate Spodoptera littoralis larvae and reduced cell viability of HepG2 cells of the extracts containing Iboga alkaloids, whilst the javaniside derivatives containing hydrophilic fraction did not show any effects. These findings indicate a high flexibility in the formation of bioactive indole alkaloid aglycones by Tabernaemontana species and also evidence similar accumulation trends in both species as well as indicate that biosynthetic routes leading to oxindole alkaloids like javanisides are more widespread than reported. Furthermore, the incorporation of the three novel compounds into potential biosynthetic pathways is discussed.

Synergistic effects of suppress resistance of cypermethrin and chlorpyrifos in the cotton leafworm, Spodoptera littoralis (Boisduval) populations in Egypt

Synergistic effects of suppress resistance of cypermethrin and chlorpyrifos in the cotton leafworm, Spodoptera littoralis (Boisduval) populations in Egypt

More than trichomes and acylsugars: the role of jasmonic acid as mediator of aphid resistance in tomato

ABSTRACT This study investigates the impact of priming on the resistance of tomato plants to the potato aphid Macrosiphum euphorbiae, focusing on the role of glandular trichomes. Glandular trichomes are specific hairs that provide protection to tomato plants against herbivorous insects. The experimental priming conducted in this study revealed that prior infestation by Spodoptera littoralis caterpillars increased the plant's resistance against M. euphorbiae, pointing at the jasmonic acid (JA) signaling pathway in regulating this plant-aphid interaction. Glandular trichomes type IV were effective against aphids regardless of the previous infestation. Using JA-deficient tomato (spr2), we observed that M. euphorbiae multiplication increased, while the number of aphids on salicylic -deficient NahG plants was lower than in the wildtype Moneymaker. These findings emphasize the crucial role of the JA signaling pathway in tomato plant resistance to aphids and the importance of glandular trichomes to enhance plant defences against pests.

First review of the subfamily Agathidinae Haliday, 1833 (Hymenoptera: Braconidae) in Egypt, with new records and the description of a new species of Camptothlipsis Enderlein, 1920

Summary Altogether, seven species of Braconidae Agathidinae, in six genera and three tribes (Agathidini, Disophrini, and Earinini) are recorded from Egypt, of which four genera (Agathis Latreille, Camptothlipsis Enderlein, Disophrys Foerster, and Earinus Wesmael) and four species (Agathis anglica Marshall, 1885; Coccygidium luteum (Brullé, 1846), Disophrys caesa (Klug, 1885), and Earinus sp.) are newly recorded for Egypt. Camptothlipsis similis n. sp., reared from a crambid host species (Chilo sp.), is described and illustrated. A brief description and the distribution of each species are given. A key to species of the subfamily Agathidinae Haliday, 1833 in Egypt, as well as a checklist, are presented. Most of the collected species have a Palaearctic affinity; only two species, Coccygidium luteum (Brullé) and C. melleum (Roman), have an Afrotropical distribution. Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae) is here recorded for the first time as a host for Coccygidium melleum (Roman).