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The study was done to find out what would happen to the number of generations of adult Spodoptera littoralis (Boisd.) moths if the temperature went up in 2025, 2050, 2075, and 2100. This was done by doing a comparison field study in Sharkyia Governorate for four years, from 2018 to 2021.The adult moths' population recorded nine generations. The general averages of generation time and coefficient variance were 40 ± 17; 35 ± 10 and CV by 42.2; 28.4 days, respectively. The general average of thermal heat units was 556 ± 5; 558 ± 3 and CV by 0.9; 0.5 units, respectively. In the predicted years, in 2025 to 2100, the average generational duration ranged between 33 and 37 days, with a standard deviation ranging between 11 and 14 days, and CV values at 33.5 to 38.3 day less than that in the field study. The generations' time was 48 days in the field study, while the values decreased to 44 days in 2025 and continued to decline in 2050, 2075, and 2100 to 40, 37, and 33 days, respectively. The period for generation growth in the expected years was shorter than in the field study years, so the generations will occur earlier. The thermal constant remained nearly constant across generations and from peak to peak, while the thermal units in the year increased from 5024 units in the average of four years of field study to 5366, 5659, 5881, and 6065 units in the expected years 2025, 2050, 2075, and 2100, respectively. In 2025, S. littoralis adult moths recorded nine generations; it increased to ten in 2050, continued at ten in 2075, and increased to eleven generations in 2100. There is an inverse relationship between temperatures and the number of days required to complete the growth of the generation, that is, the higher the temperature, the fewer the days required to complete the generation period. [ABSTRACT FROM AUTHOR]

Simple Summary: Spodoptera littoralis, the Egyptian or African cotton leafworm, is a major agricultural pest in Africa, Mediterranean Europe, and the Middle East, affecting crops like cotton, soybeans, and tomatoes. This pest damages various plant parts, leading to significant product losses. Control strategies primarily use synthetic insecticides, which pose problems such as resistance, environmental harm, and negative effects on non-target organisms. This study explores a garlic essential oil-based nanoemulsion as an alternative control tool. Garlic-EO nanoemulsion effectively killed larvae and reduced feeding activity in laboratory trials. These findings highlight the potential of botanical insecticides for sustainable pest management. 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. [ABSTRACT FROM AUTHOR]

The common cutworm, Spodoptera litura, is a serious insect pest of many vegetables and crops worldwide. Entomopathogenic nematodes (EPN) have been utilized as biological control agents for controlling various insect pests, including the larvae of S. litura. Many indigenous EPN have been recognized to be more effective in specific field applications. Among the 160 soil samples collected in undisturbed areas of western Thailand, three samples tested positive for EPN. Three indigenous EPN were identified as Steinernema siamkayai namely, EPNKU63, EPNKU70 and EPNKU85, based on ITS and D2/D3 expansion region analysis of the 28s rRNA genes. Additionally, genetic analysis of the symbiotic bacteria using recA rRNA sequences confirmed their identity as Xenorhabdus stockiae namely, PEPNKU63, PEPNKU70 and PEPNKU85. To evaluate their initial biocontrol potential against the 6th instar larvae of Galleria mellonella, virulence assays were conducted. The application of 100 infective juveniles (IJs)/insects resulted in the mortality of 80–100% of G. mellonella larvae after 72 h. When symbiotic bacteria were applied at 1 × 106 cells/insect, they exhibited 63–93% mortality against G. mellonella larvae after 120 h. In further laboratory tests, three S. siamkayai isolates achieved 100% mortality of 3rd instar Spodoptera litura larvae within 72 h, with LC50 values ranging from 29 to 30 IJs/insect. In screenhouse experiments, it was revealed that all S. siamkayai isolates displayed substantial virulence, ranging from 62% to 74%, against 3rd instar S. litura larvae within 72 h. This study demonstrates the biocontrol potential of S. siamkayai in controlling S. litura larvae. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effect of recommended LC50 concentration of three commercial bio insecticides; (Protecto® (Bacillus thuringiensis kurstaki), Viruset® (Spodoptera littoralis NPV), Profect® (Btk & SpliNPV) on fat body and internal organs of the spodoptera littoralis larva treated with these bio insecticides. The treated larvae were dissected and examined under the converted microscope and transmission electron microscope. Results showed that the three compounds have significant effect on fat bodies and internal organs of larva. The greatest effect was observed by the profect compound followed by protecto and viruset. The combination of bacteria and virus increased the amount of fat body compared with suing virus and bacteria individually. Thus, our findings indicated that the combination of bacteria and virus increased the efficiency of each other. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arab Journal of Plant Protection is the property of Arab Society for Plant Protection and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Spodoptera littoralis is an important agricultural pest; thus, knowledge about the effect of latex serum and latex-synthesized nanoparticles of Calotropis procera on this species can assist in its management.. Nanotechnology is currently taking root in the agriculture economy as a substitute for pest management that is targeted, safe, and effective. The repellent and antifeedant efficacy of C. procera latex serum and its nanoparticles against S. littoralis fourth instar larvae was investigated in this work. Methods: The process of synthesizing silver nanoparticles has been carried out, followed by their subsequent characterization. The objective of this study was to assess the antifeedant properties of the latex serum and its nanoparticles against the 4th instar larvae of S. littoralis through the implementation of a bioassay. Results: With rising latex serum content, the proportion of repellency and hunger rose. In comparison to insects injected with latex serum, utilizing nanoparticles of LAgNPs with this larva via injection resulted in much increased mortality. Conclusion: According to the findings of this study, insects injected with LAgNPs died at a substantially higher rate than insects injected with latex serum. LAgNPs was efficient against S. littoralis larvae and can thus be utilized to specifically control the pest. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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.

Insecticide resistance in Egypt is a major barrier to the successful management of Spodoptera littoralis (Lepidoptera: Noctuidae). One way to overcome insecticide resistance could be the formulation of insecticides with synergists that counteract metabolic resistance. Therefore, the effect of three synergists on the efficacy of cypermethrin and chlorpyrifos was evaluated in three S. littoralis populations. The Marsa Matruh (MAR) and Damietta (DAM) populations were more susceptible to cypermethrin and chlorpyrifos than the Kafr El-Shaikh (KAF) population, which showed an increase in resistance levels (ranging from 48.49- to 170.86-fold). Resistance levels in all field populations decreased markedly when piperonyl butoxide (PBO) synergized cypermethrin, with a synergism ratio (SR) of 2.47 and significantly suppressing 59% of resistance in the highly resistant population of S. littoralis collected from KAF. In addition, S,S,S-tributyl phosphorotrithioate (DEF) suppressed chlorpyrifos resistance in the KAF population by 24% with an SR of 1.32-fold higher than chlorpyrifos alone. On the contrary, diethyl maleate (DEM) did not cause a statistically significant change in the toxicity of both cypermethrin and chlorpyrifos in all field populations. From these findings, it is recommended to use synergists as a countermeasure to the problem of insecticide resistance in S. littoralis and to restore the efficacy of these insecticides in Egyptian fields. [ABSTRACT FROM AUTHOR]

Insecticide resistance is a significant problem in insect management that can result from several processes including target-site change and increased activity of detoxifying enzymes. Spodoptera littoralis is one of the most resistant insect pests. For more effective insect management, alternatives to synthetic pesticides are encouraged. One of these alternatives is essential oils (EOs). Cymbopogon citratus EO and its main constituent citral were, therefore, considered in this study. The results revealed that C. citratus EO and citral exhibited significant larvicidal activity against S. littoralis, and the former was insignificantly more toxic than the latter. Additionally, treatments significantly affected the activity of detoxification enzymes. Cytochrome P-450 and glutathione-S-transferase were inhibited, while carboxylesterases, a-esterase and β-esterase, were induced. The molecular docking study indicated that citral bonded with the amino acids cysteine (CYS 345) and histidine (HIS 343) of cytochrome P-450. This result suggests that interaction with cytochrome P-450 enzyme is one key mechanism by which C. citratus EO and citral act in S. littoralis. The results of our study are hoped to contribute to a better understanding of the mechanism of action of essential oils at the biochemical and molecular levels and provide safer and more efficient pest management solutions for S. littoralis. Graphical Abstract [ABSTRACT FROM AUTHOR]

A number of interesting N-(4-chlorophenyl)-2-phenoxyacetamide derivatives were synthesized through interaction of N-(4-chlorophenyl)-2-(4-formylphenoxy)acetamide (1) with cyanoacetamide derivatives 2a-e, hydrazine derivatives, activated nitriles and acetophenone to yield novel acrylamide, hydrazone, acrylonitrile and chalcone derivatives, respectively. Acrylamide derivatives 3a-e were used as precursors for synthesis of 2-pyridone derivatives comprising phenoxyacetamide moiety. The structures of the newly synthesized compounds were avowed by different spectroscopic techniques such as FT-IR, 1H-NMR, 13C-NMR, and mass spectroscopy. Finally, the insecticidal efficacy of the newly synthesized phenoxyacetamide derivatives was tested using the cotton leafworm Spodoptera littoralis. Among all, compounds 12, 6 b and 6c exhibited excellent results. [ABSTRACT FROM AUTHOR]

The cotton leafworm, Spodoptera littoralis (Boisd) (Lepidoptera: Noctuidae), is an important and polyphagous pest that causes considerable damage to agricultural crops in Iran and many other parts of the world. In this research, the effects of seven different leafy vegetables, including Purslane, Chives, Parsley, Basil, Dill, Coriander and Mint were assessed on the biological and life table parameters of S. littoralis at 25 ± 2°C, 60 ± 5% RH, and a photoperiod of 16:8 (L:D) hours. The longest development period was in the insects fed on Purslane (40.67 ± 9.49 days), and the shortest was obtained on Basil (30.22 ± 0.42 days) and Coriander (30.76 ± 0.32 days). The lowest value of fecundity was on the Purslane (199.32 ± 21.82 eggs), and the highest was recorded on the Coriander (481.06 ± 62.82 eggs), Basil (428.97 ± 28.68 eggs) and Chives (409.26 ± 26.58 eggs) vegetables. In addition, the results of demographic parameters showed that the intrinsic rate of increase (r) and net reproductive rate (R0) of S. littoralis were lowest on the Purslane (0.124 ± 0.072 day-1, and 67.92 ± 17.51 offspring, respectively), and highest values were observed on the Coriander (0.161 ± 0.064 day-1, and 275.70 ± 53.94 offspring, respectively). The cluster results indicated that Coriander was relatively susceptible host for feeding of S. littoralis. In contrast, the Purslane was found the relatively resistant (least appropriate) host for this pest, which could be useful in the development of integrated pest management strategies, and understanding plant-herbivore interactions.

The application of nuclear techniques to control one of the most important lepidopteran insect pests: the Egyptian cotton leafworm, Spodoptera littoralis is discussed in this study. All experiments had the objective of finding the dose of gamma radiation capable of causing sterility in the first generations by irradiating the parental generation. For S. littoralis, 6th instar larvae were irradiated with doses of 40, 80, 120 and 160 Gy. The larval survival was 93%, 90%, 88%, 85% and 97% at 40, 80, 120, 160 and 0 Gy, respectively. The pupal survival was 88, 85, 83, 80 and 98% at the same doses. Hence, there was a reduction in survival and emergence to the adult stage after treating S. littoralis larvae with radiation. Also, the latent effects of the tested gamma doses on 6th instar larvae of S. littoralis are recorded. The total number of eggs/female and egg fertility were significantly reduced as compared to control, these effects were increased with increasing the dose. It is concluded that radiation is a promising control method for S. littoralis and other related lepidopteran species. [ABSTRACT FROM AUTHOR]

This study was performed to assess the resistance levels in a cotton leafworm (CLW), Spodoptera littoralis (Boisd) field strain in comparison with a laboratory strain toward alpha-cypermethrin, chlorpyrifos, methoxfenozide, chlorantraniliprole, and chlorfluazuron. Their Ovicidal activity and residual toxicity against neonates were also evaluated. Glutathione S-transferases (GST) and total esterases activities of of 2nd and 4th larval instars treated with these insecticides were determined. The field strain exhibited different level of resistance where cypermethrin, chlorpyrifos, and methoxfenozide ratios (RR) were 12.7, 48.0, and 13.8, respectively for 2nd instar, while 4th instar is only resistant to cypermethrin, chlorpyrifos with RR of 120.8 and 19.0 compared to lab strain. Concerning the ovicidal and residual toxicity at the recommended field rate, cypermethrin, chlorpyrifos, chlorantraniliprole, and chlorfluazuron achieved mortality of treated eggs and neonates of lab strain 95.3, 98.9, 93.3, and 96.8%, respectively as well as 75.6, 70.0, 85.2 and 91.6%, respectively against field strain. However, methoxyfenozide showed a non-significant difference between lab and field strains. GST and esterases activities were significantly higher in the field strain compared with that of lab strain. It can be concluded that monitoring of insecticide resistance is a crucial step for the plant protection and resistance management programs. [ABSTRACT FROM AUTHOR]

It is important to understand the effects of temperatures on Egyptian cotton leafworm Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) which damages a wide variety of crops in the Middle East and is one of the major economic pests of cotton in Egypt. Therefore, the investigating was designed to study the effect of fluctuation temperatures on the field strain in Abnob city, Assuit Governorate during the 2017 and 2018 cotton growing seasons. On the other hand, the results compared with the laboratory strain under constant temperature (25°C). The biochemical parameters were measured on the 4th larval instars for both strains. Biochemical analyses were performed to determine the effects of fluctuation and constant temperatures on field and laboratory strain on total proteins, lipids, carbohydrates and free amino acids as well as metabolic digestive, neural and detoxification enzymes. It's clear from the results that the GST, GOT, AchE, Alpha esterases, Beta esterases as well as, the activity levels were increased significantly by field strain. While the free amino acids, total proteins, proteases, lipases, amylase were decreased significantly by field strain and no significant changes were detected between field and laboratory strains in total carbohydrates, total lipids, trehalase and GPT. [ABSTRACT FROM AUTHOR]

Abstract The mortality of the Alabama argillacea and Chrysodeixis includens (Lepidoptera: Noctuidae) larvae caused by the kaolin inert powder and the entomopathogenic fungus Beauveria bassiana were determined under laboratory conditions. Using the caterpillar submersion method, the CG 138 B. bassiana isolate was more pathogenic to A. argillacea than the CG 70, GC 82, ESALQ 634, and ESALQ 645. All five tested isolates caused similar mortality of C. includens. The mortality of first-instar larvae of A. argillacea and C. includens by feeding on leaf-disc impregnated with B. bassiana (CG 138) and kaolin was also determined. Higher A. argillacea mortalities were observed in the B. bassiana (CG 138) treatments, regardless of the presence of kaolin. However, the activity of kaolin + B. bassiana (CG 138) against C. includens was higher than each ingredient alone, indicating an additive action against C. includes larvae. The mortality of A. argillacea and C. includens larvae treated with kaolin + B. bassiana (CG 138) was similar, and the A. argillacea mortality was higher than that of C. includens with kaolin and B. bassiana (GC 138) separated. The treatment kaolin + B. bassiana (CG 138) is promising for the simultaneous management of these two defoliator pests, mainly A. includes. In addition, the monophagous A. argillacea is more susceptible to both kaolin and B. bassiana (GC 138) than the polyphagous C. includens, suggesting that the nutritional ecology plays an important role in the susceptibility of these defoliator species to alternative insecticides.

The toxicological effects of some insecticide mixtures (chlorpyrifos, pyridalyl, chlorantraniliprole, emamectin benzoate, and methoxyfenozide), against the 3rd instar of Spodoptera larvae were evaluated. The results indicated that, LC50 values for each insecticide were 12.44, 0.88, 0.08, 0.16 and 3.35 mg L-1 respectively, and 0.458, 0.009, 0.0014 and 0.357 mg L-1 respectively.Also, the LC50 values of chlorpyrifos are increased by larvae weight increased. LC50 values of chlorpyrifos as a function of post-feeding initiation of Spodoptera larvae to pyridalyl, chlorantraniliprole, emamectin benzoate, and methoxyfenozide after two days (single exposure) were 1.33, 1.99, 0.74, and 0.37 mg L-1 respectively. Therefore, post-feeding initiation of larvae to previous insecticides tremendously decreased LC50 values of chlorpyrifos.Also, the percent inhibition of AChE from Spodoptera head capsules by chlorpyrifos, pyridalyl, chlorantraniliprole, emamectin benzoate, and methoxyfenozide (LC10 equivalent concentrations) were 44.5, 23.4, 19.4, 33.5, and 15.4%, respectively. The percent inhibition of AChE from Spodoptera head capsules by chlorpyrifos either pre-treatment or post-treatment with pyridalyl, chlorantraniliprole, emamectin benzoate, and methoxyfenozide were increased. This indicates that the toxic potential of these pesticides for the tested organism is greater when present in a mixture than in an individual.

Abstract Background The cotton leafworm, Spodoptera littoralis (Boisd.), is a serious economic pest in Egypt. Pest control depends mainly on chemical control with several pesticides include conventional and modern insecticides. Comprehensive analysis of pesticides impacts needs to investigate sublethal effects in addition to lethal effect. Results In the current study, the leaf-dip bioassay method was used to evaluate emamectin benzoate (EMB) sublethal concentrations. Results showed that EMB proved high toxicity against S. littorals with LC50 value of 0.019 mg liter−1. Life table analysis showed that treatments with LC5 and LC15 prolonged larval period, mean longevity of males and females, mean generation time (T), doubling time (DT), adult preovipositional period (APOP), and total preovipositional period (TPOP) compared with control. On the contrary, net reproduction rates (R 0), intrinsic rates of increase (r), finite rate (λ), fecundity, gross reproductive rate (GRR), and relative fitness were decreased compared to control. Conclusions The current study clarified that sublethal concentrations of EMB induce adverse effects and suppress the population growth of S. littorals. Our results would be useful to assess the overall effects of EMB on S. littorals and can contribute effectively in pest management.

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background The cotton leafworm, Spodoptera littoralis (Boisd.), is one of the most dangerous pests in Egypt and Africa, causing significant economic loss of cotton crop yield. The frequent use of insecticides to control this insect has led to the development of a generation’s resistance to them. The need of a new, safe control method and effective insecticides has become necessary after the recent increases in environmental pollution and insect resistance. This study is devoted to developing a novel synthetic scheme to produce a pesticide nanocomposite of very high efficiency compared to the originals. The nature of its chemical binding has been investigated via Fourier transform-infrared (FT-IR) and transmission electron microscopy (TEM) techniques. Results In this work, the method is based on using silver nanoparticles (AgNPS) as a pesticide carrier by loading the organophosphorus pesticide profenofos on to their surface. The profenofos, AgNPS alone and nanocomposite profenofos (AgNPS@P) have been tested against second- and fourth-instar larvae of laboratory and field cotton leafworm. Our findings indicate that the AgNPS@P is more effective on cotton leafworm larvae than each of profenofos and nanosilver alone. The activity of AgNPS@P (LC50 = 0.94 and 5.15 ppm) was increased to 85 and 69 times more than that of profenofos (LC50 = 79.52 and 356.97 ppm) against second- and fourth-instar larvae of field cotton leafworm. Conclusions This method may be successful for reducing environmental pollution and the resistance of this pest to many pesticides.

An ultralow amount of sub‐micron spherical SiO2 particles encapsulating 7 wt% crude orange oil (SiliOrange) suspended in water shows surprisingly high insecticidal activity against the cotton leafworm Spodoptera littoralis, and significantly reduces the progeny of cotton aphid Aphis gossypii under laboratory testing conditions. Considering the ease of reproducible preparation of the material and the biocompatible nature of both silica and orange essential oil, these results may open the route to sustainable pest control using new biopesticide water‐based formulations based on sol–gel microencapsulated orange oil. [ABSTRACT FROM AUTHOR]

Plants' defenses against herbivores usually include both resistance and tolerance mechanisms. Their deployment has predominantly been studied in either single‐plant genotypes or multiple genotypes exposed to single herbivores. In natural situations, however, most plants are attacked by multiple herbivores. Therefore, aims of this study were to assess and compare the effects of single and multiple herbivores on plant resistance and tolerance traits, and the consequences for overall plant performance. For this, we exposed multiple genotypes of wild woodland strawberry (Fragaria vesca) to jasmonic acid (JA), to mimic chewing herbivory and induce the plants' defense responses, and then introduced the generalist herbivore Spodoptera littoralis to feed on them. We found that woodland strawberry consistently showed resistance to S. littoralis herbivory, with no significant genetic variation between the genotypes. By contrast, the studied genotypes showed high variation in tolerance, suggesting evolutionary potential in this trait. Prior JA application did not alter these patterns, although it induced an even higher level of resistance in all tested genotypes. The study provides novel information that may be useful for breeders seeking to exploit tolerance and resistance mechanisms to improve strawberry crops' viability and yields, particularly when multiple herbivores pose significant threats. [ABSTRACT FROM AUTHOR]

BACKGROUND: The cotton leafworm, Spodoptera littoralis, is one of the most destructive pests in the Mediterranean basin, being predominantly controlled using synthetic chemical pesticides. Strain EAMa 01/58‐Su of the fungus Metarhizium brunneum and the parasitoid Hyposoter didymator are promising biological control agents for this pest. In this study, we assessed the compatibility between these two agents to control S. littoralis under joint attack scenarios. RESULTS: Firstly, the direct and indirect effects of the fungus towards parasitoid adults were studied. The fungus significantly decreased life expectancy of the parasitoid (mortality = 62.5%; mean lethal concentration = 1.85 × 106 conidia ml−1; average survival time = 92.2 h) when applied at high concentrations (108 conidia ml−1), whereas it did not affect the reproductive potential of the parasitoid females during the 3 days after treatment. Secondly, the combinations between the two agents to control S. littoralis under different simultaneous use scenarios (inoculation of S. littoralis larvae with the fungus before being exposed to parasitoid females and vice versa) were investigated, with additive effect in all cases. A significant effect on fitness (preimaginal development time and reproductive potential) of the F1 parasitoid generation were detected. Moreover, parasitization significantly reduced the total hemocytes in S. littoralis hemolymph compared with the control, promoting fungal infection. Finally, parasitoids showed a significant preference for non‐inoculated S. littoralis larvae. CONCLUSIONS: We demonstrated compatibility (additive effect) between fungus and parasitoid under different joint attack scenarios to control S. littoralis in laboratory conditions. However, this will be supported by our ongoing greenhouse and field studies. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fipronil and emamectin benzoate (EMB) are effective insecticides for controlling cotton leafworm, Spodoptera littoralis. Fipronil works by blocking gamma-amino butyric acid (GABA) gated chloride. In contrast, EMB is activating GABA transporters. The objectives of our study were to assess relative toxicity of the technical fipronil and EMB alone and in mixture against S. littoralis. In addition, the GABA content was simultaneously determined using HPLC. Technical fipronil and EMB and their mixtures were applied topically to the fourth-instar larvae, and their LD50 values were estimated after 48 h. Results demonstrated that the LD50 for EMB applied alone was 0.751 ng/larva which was much less than for fipronil 7.271 ng/larva. Each of the two insecticides alone showed a significant decrease in GABA content at LD10, LD25, and LD50 doses, while their mixtures induced GABA levels. The highest potentiation was observed when both insecticides were in a mixture at the ratio of LD10:LD10 which was associated with higher increase in GABA levels. Moreover, the weight of the alive larvae was less than that was in the untreated control. However, all mixtures exhibited potentiation effect, except for the mixture of fipronil at LD50 with EMB at LD10, LD25, and LD50 that had antagonistic effect correlated with the lowest decrease in GABA level. Results suggested that lower doses of both insecticides in a binary mixture had potentiation effect against S. littoralis. This mixture could be used in combination as field application for successful and effective control of S. littoralis and would also help in managing insecticide resistance. [ABSTRACT FROM AUTHOR]

The present study is to through light on role of some insecticides (chemical insecticides (a.i. chlorphyrifos) Dursban® 48% EC, spinosyns group (a.i. spinosad) Tracer® 24% SC and insect growth regulator (a.i. lufenuron) Match® 5% EC) against insect attacking cotton cultivation Spodoptera littoralis under Egyptian conditions. The toxicological effects and biochemical analysis carried out against laboratory strain of target insects after 24 and 72 hours. Toxicity of the three insecticides chlorphyrifos, spinosad and lufenuron were tested against the 2nd instar larvae of the cotton leafworm, spodoptera littoralis. The results showed that lufenuron was more effective on the 2nd instar larvae than chlorphyrifos and spinosad. The LC25 values for lufenuron, chlorphyrifos and spinosad were 0.0005, 2.21 and 8.1 ppm, respectively. The biochemical study used for tested insecticides at LC25 on some biocomponents namely acetylcholinesterase (AchE), glutathione-s-transferase (GST), chitinase, phenoloxidase, aspartate (AST) and alanine (ALT) aminotransferases, α-esterase (α-EST), total protein and protein gel electrophoresis for laboratory strain were investigated. The tested chlorphyrifos and lufenuron were significantly increased (AchE). Spinosad was significantly decreased (GST) and phenoloxidase. Spinosad and lufenuron significantly increased (α-EST) and (chitinase) (ALT). Chlorphyrifos caused significantly decreased on α-esterase and total protein and (AST). Lufenuron significantly decreased total protein and phenoloxidase. Spinosad showed insignificant increase in (AchE) and total protein (levels). Chlorphyrifos decreased both of phenoloxidase and (ALT) levels insignificantly and increased the levels of (GST) and chitinase, while lufenuron, recorded insignificant decrease in GST levels. The total body proteins of 2nd instar larval of S. littoralis treated with LC25 of insecticides performed by SDS-PAGE. Control and different treatments were separated into 56 different bands according to their relative frequencies (Rf values), and molecular weights (MW). Samples of electrophoresis were carried out for three different insecticides namely chlorphyrifos, spinosad and lufenuron which used to treat insects. The treatment with insecticides on protein gel electrophoresis led to detection of new bands, and disappeared some bands in comparison to control. It is concluded that treatment with insecticides have strong efficacy on the soluble protein in the body of insects. [ABSTRACT FROM AUTHOR]

An experiment was carried out to evaluate the effect of using different host plants Castor bean, Clover, Cabbage, Broad bean, Sugar beet, and Cotton as foods for Spodoptera littoralis (Boisd.) larvae on certain biological aspects of the insect. The study was achieved under laboratory conditions of (25 ± 1°C) and 75 ± 5% R.H. for obtained results and statistical analysis cleared that the developmental stages, fecundity, and life parameters were affected by the different hosts whereas the shortest larval duration (18 ± 0 days) was recorded for larvae fed on clover and the longer (25.2 ± 0.37 days) resulted when larvae were offered sugar beet. The pupation percentages on sugar beet leaves were lowest (58.4 ± 2.38%) and highest pupation percentages were (78.4 ± 1.08%) when larvae fed on clover leaves. Moreover, adult emergence Percentage was (98 ± 0.45%) in both clover and broad bean (95.58 ± 0.61%) on sugar beet. The moths produced from larvae fed on broad bean laid the highest number of eggs (1915 and 1847 eggs per female) in both generations, respectively and the least numbers of eggs deposited were (1081 and 994 eggs/female) on cabbage in the two generations, respectively. [ABSTRACT FROM AUTHOR]

Toxicity of five insecticides belonging to different groups of chemicals, namely: chlorpyrifos, methomyl, emamectin benzoate, protecto and biovar to cotton leafworm were evaluated under the field and laboratory conditions. The effect of the tested chemicals on some biological aspects of 2nd and 4th instar larvae of the cotton leafworm, Spodoptra littoralis (Boisd.) were investigated. The lethal concentrate (LC50 and LC90) values were calculated after 24, 48, and 72 hr., post-treatment. The obtained results showed that there was a wide range of toxicity of the tested pesticides; however the insecticide bestban showed to be the highest toxic compound effect against 2nd and 4th instar larvae, with LC50 and LC90 values after 72 hr., post-treatment recording 0.05, 0.22 mg/l and 0.15, 1.10 mg/l for 2nd and 4th instar larvae, respectively. On the other hand, the biopesticide biovar exhibited the lowest toxicity to the tested larvae at both levels of toxicity (LC50; LC90 values after 72 hr., recording 414; 856 mg/l and 1100; 1740 mg/l) for 2nd and 4th instar larvae, respectively. The other tested insecticides occupied an intermediate position between the highest and the lowest toxic pesticides. Regarding the biological effects, results showed that, the tested insecticides induced a clear reduction in mean larval weight and mean pupal weight compared with the control. The tested insecticides affected the larval duration, pupal duration, pupation, adult emergence and adult longevity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Insect resistant soybean {Glycine max (L.) Merr.} cultivars could reduce pesticide use in controlling insects, resulting in less risk to the environment. This study was conducted to develop an effective field and SSR analysis screening procedurs to screen 15 soybean genotypes . A field experiment was conducted for their resistance , and showed that genotypesH105 andH153 recorded the highest insect resistance and low defoliation rating of 0.0 and 0.1 respectively, followed by H10L10A, L162, and H1L1. Genotype AGS-129 showed highest insect susceptibility and high defoliation rating of 4.0. Genotypes H10L10A, H 153, and H1L1 recorded the highest seed yield values due to the number of branches plant , number of pods plant , and 100-seed weight indicating that these genotypes could be recommended particularly with high resistance to cotton leaf worm. A total of 13 SSR primer pairs were used to generate 39 bands (alleles). Nearly 92% (12) of the primer pairs amplified SSR alleles of expected size and 11 SSR loci were polymorphic. The polymorphic SSRs were successfully used to differentiate among 15 genotypes. These markers could be particularly useful for genetic differentiation cotton leaf worm resistance. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore the potential of ZnO-nanoparticles (NPs) and Cu-doped ZnO-nanoparticles (NPs) as insecticides for controlling the population of Spodoptera littoralis , a major pest in Egyptian fields. The researchers employed various characterization techniques like zeta potential, XRD, Fourier-transform infrared spectroscopy (FTIR) spectroscopy, scanning electron microscopy, and transmission electron microscopy to analyze and identify the nanomaterials used. The study investigated the effects of different concentrations of nanomaterials, ranging from 1 % to 5 %. The results revealed that the presence of Cu-doped ZnO-NPs led to a significant reduction in the pest population compared to the control group. Notably, the highest concentration of 5 % Cu-doped ZnO-NPs exhibited a toxic effect on Spodoptera littoralis , resulting in a remarkable 95 % reduction in their population after 16 days of treatment. Additionally, the findings demonstrate that Cu-doped ZnO-NPs have effective insecticidal properties and are cost-effective, making them a viable option for local application in pest control. Finally, the research highlights the potential of Cu-doped ZnO-NPs as an environmentally safe and efficient insecticide against Spodoptera littoralis in Egyptian fields. The study emphasizes the utility of nanomaterials in pest management, which could significantly reduce the reliance on conventional insecticides, mitigating potential environmental and health risks. • Innovative Cu-doped ZnO-nanoparticles combat Spodoptera littoralis, revolutionizing Egyptian pest control. • Remarkable 95% Spodoptera littoralis reduction in 16 days with Cu-doped ZnO-nanoparticles. • Comprehensive nanomaterial analysis: zeta potential, XRD, SEM, TEM, and FTIR spectroscopy. • Environmentally sound pest control: Cu-doped ZnO-nanoparticles offer safety and cost-effectiveness. • Nanotechnology's eco-friendly promise: Reduced reliance on traditional insecticides for sustainable agriculture. [ABSTRACT FROM AUTHOR]

The aim of the current study was to delve into the causes of mortality of Spodoptera littoralis larvae feeding on Metarhizium-colonized plants in the absence of fungal outgrowth on the cadavers as previous studies reported and to elucidate the possible indirect effects of this fungus-colonized diet. The effect was evaluated in experiments conducted using leaf discs of colonized plants and in planta using fungus-colonized whole plants. The mortality rates of larvae fed on Metarhizium-colonized melon leaves were 45.0% and 87.5%, and the average survival times were 6.6 and 3.1 days in experiments performed with discs and in planta, respectively. Notably, these mortality levels were not associated with observed apoptosis mediated by caspases 1, 3-7 and 8; thus, further investigation into the possible immune system reaction of the insect after the ingestion of colonized plants is required. The leaf consumption of S. littoralis larvae fed on melon-colonized leaves was lower than that on control plants in the disc experiments but not in experiments conducted in planta. In this regard, in experiments performed in planta, plant damage increased larval mortality in both fungally challenged and control larvae. There was also a meaningful effect of exposure to Metarhizium-colonized melon leaf discs on S. littoralis fitness, with significant reductions in 39.0% and 22.0% in female fecundity and egg fertility, respectively, detected in females emerging from pupae developing from larvae surviving exposure to colonized plant discs; all larvae died in the in planta experiments. Hence, the present work presents new findings revealing the high potential of endophytic entomopathogenic fungi to improve the outcome of foliar applications against chewing insects in the short, mid- and long term, by the reduction of the reproductive potential of surviving adults and reveals new insights into the development of bioassays with whole plants for more detailed evaluation of the impact of these fungi as endophytes used for plant protection.

ABSTRACT The host acceptance behavior and environmental factors as temperature affect the feeding behavior of Lepidoptera pests. Thus, they must be considered in studies about the risk potential of resistance evolution. The current study sets the differences in the feeding behavior of neonate Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) larvae exposed to Bt and non-Bt cotton plants, under different temperatures and time gap after hatching. Two cotton cultivars were used: the Bt (DP 404 BG - bollgard) and the non-transformed isoline, DP 4049. We found that the feeding behavior of neonate A. argillacea is significantly different between Bt and non-Bt cotton. Based on the number of larvae with vegetal tissue in their gut found on the plant and in the organza as well as on the amount of vegetal tissue ingested by the larvae. A. argillacea shows feeding preference for non-Bt cotton plants, in comparison to that on the Bt. However, factors such as temperature and exposure time may affect detection capacity and plant abandonment by the larvae and it results in lower ingestion of vegetal tissue. Such results are relevant to handle the resistance of Bt cotton cultivars to A. argillacea and they also enable determining how the cotton seeds mix will be a feasible handling option to hold back resistance evolution in A. argillacea populations on Bt cotton, when it is compared to other refuge strategies. The results can also be useful to determine which refuge distribution of plants is more effective for handling Bt cotton resistance to A. argillacea.

Different formulations of pepper mint oil, i.e. bulk, nano-emulsion and nano-encapsulation were evaluated against 2nd and 4th instar larvae of the cotton leafworm Spodoptera littoralis (Boisd.). Their effects on enzymatic activities and bionomics were also investigated. Transmission Electron Microscopy (TEM) showed that the mean particle size of the prepared nano-emulsion ranged between 20-90nm. The encapsulation efficiency and loaded capacity percentages exhibited that distilled H2O was more suitable than ethanol in preparation of nano-encapsulation particles. Bioassay treatments showed LC50's on 2nd instars larvae were 70.59, 12.23 and 21.72 ppm for pepper mint oil, pepper mint nano-emulsion and loaded nanoemulsion, respectively. While on 4th instars these values were 80.47, 26.14 and 67.69 ppm, respectively. LC90's on 2nd instars were 104.75, 33.97 and 30.14 for pepper mint oil, pepper mint nanoemulsion and loaded nano-emulsion, respectively. While on 4th instars these values were 177.66, 71.37 and 102.29 ppm. Toxicity index and relative potency proved that nano-emulsion was more effective than loaded nano-emulsion, while the bulk preparation was the least effective one. Results of enzymatic activities showed marked effects of the three formulations of mint oil, significant inhibitions were recorded for amylase, invertase, trehalase, protease and alkaline phosphatase, while significant increase in activities of cuticle phenoloxidase and chitinase. Effects of adding the three formulations to artificial diet of 2nd instar showed significant effects of the insect bionomics. Larvae durations, percentage mortalities, were increased as well as larval malformations. Also, pupal duration, percentage pupal mortality and pupal malformation were increased, while pupal weight was decreased. Adults longevity showed insignificant effects, while female fecundity and egg % fertility showed significant responce. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Brassica napus plant has defensive secondary metabolites against phytophagbus insects and pathogens. In extraction process, the end product contains traces of residual solvent, so, the solvent should not be non-toxic and should not interfere with the bioassay. The preliminary biological activity of ethanol, petroleum ether, methylene chloride, ethyl acetate and butanol fractions of B. napus leaves was investigated against the 4th instar larvae of 5podoptera littoralis under laboratory conditions. The ethanolic fraction showed the most toxic effect against the 4th instar larvae of 5. littoralis. By phytochemical screening, B. napus leaves contain flavonoids as a major constituent. Four flavonoid compounds were isolated as crystals by column chromatographic technique using silica gel and purified on Sephadex LH-20. Their structures were elucidated as Quercetin (1), Kaempferol (2), Kaempfero/-3-0-g/ucoside (3) and Quercetin-7-0-g/ucoside (4) by using UV and 1H-NMR techniques. On toxicological studies, LCso values (0.455 and 0.091 gm/100 ml) at 7 and 14 days post treatment, respectively, showed that the toxicity of B. napus extract increased with increasing concentration and time post treatment. This indicated that B. napus extract can be used as green insecticide to control the cotton leafworm, 5. littoralis. [ABSTRACT FROM AUTHOR]

Hexane (Hex) extracts of fresh navel orange (citrus sinensis) and lemon (citrus limon) peel were prepared to isolate and identify toxic bioactive secondary metabolites for potential use as natural ecofriendly biopesticides against the cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae). Hex extracts were fractionated by column chromatography. The fractions that showed activity against the larvae, were identified and quantified by gas chromatography combined to mass spectrometry(GC/MS), after checking component profile by thin layer chromatography (TLC). The results revealed that F2 and f3 fractions were the toxic active fractions of both lemon and orange peel Hex extracts, but lemon fractions were more toxic than orange ones. F2 and f3 fractions of orange extract causd 60 and 20% larval mortality, respectively. Both lemon extract fractions caused 100% morality. Orange fractions had approximately equal dlimonene content c~s6%) as illustrated by mass spectral fragmentation pattern. However, F2 fraction contained slightly higher amounts of linalool, a-terpinol and citral than f3 fraction. The active fraction of both lemon and orange peel extracts contained d-limonene, a-pinene, linalool, citronllal and citral. Limonene oxide, geranial and terpineol were only detected in orange peel extracts. The results indicated that secondary metabolites quality and quantity differ according to the citrus spp., and the quantity of d-limonene is much lower c~1s%) in lemon than orange extracts in spite of lemon peel was more toxic than the orange. However, d-limonene was a major compound in both extracts. The results suggest that citrus extract contains many toxic compounds, other than limonene, and /or they could potentiate each other to give the observed toxicity. It could be concluded that the quantity of .d-limonene is not a determinant factor, but it is probable that other metabolites confer toxicity allover citrus extract depending on the species. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The cotton leaf worm Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) is considered one of the most harmful and destructive pest, not only for cotton crop, but also for corn, peanuts, vegetables, Lucerne, clover, ornamentals, shade trees and other types of crops and plants. The farmers used traditional chemical pesticides such as organophosphates, pyrethroids and organochlorines but the excessive amounts of these pesticides led to a severe environmental pollution. Bacillus thuringiensis bacteria were used as an ecofriendly biopesticide against cotton leaf-worm, but the main disadvantage in using bacteria was its low killing activity of the pest. Nanomaterials especially titanium dioxide nanoparticles are recently used as a nanopesticide toward several pests. In this study sodium titanate in the form of nanotubes and its composites with Bacillus Thuringiensis were examined to be used as a novel nanopesticides to resist cotton leaf-worm. Different biological features were studied for 2nd and 4th instars larvae such as adult longevity, adult sex ratio, pupation, fecundity and percent of eggs hatching (hatchability). All samples were characterized using Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), FTIR-spectroscopy and Zetasizer for zeta potential measurements. [ABSTRACT FROM AUTHOR]

Temperature is a main ecological factor affect the bioinsecticides toxicity on the destructive larval stage of the cotton leafworm (CLW). The effect of post-exposure temperatures from 13 to 39 °C , on the toxicities of two spinosyns (spinosad and spinetoram) and two avermectins (abamectin and emamectin benzoate) toward Spodoptera littoralis (BoisduVal) larvae was evaluated using topical and feeding bioassays. Spinosad and spinetoram showed negative temperature coefficient against CLW larvae. The LD50 values of spinosad and spinetoram increased by 70.21 and > 81.63 folds when temperature increased from 13 to 39 °C ,. These two compounds also showed negative temperature coefficient values (-1.71; - 9.92) in the feeding bioassay. On contrast, in feeding application abamectin and emamectin benzoate showed high positive temperature coefficient (27.79 and 194.50) when temperature increased from 19 to 39°C. The present results ascertain the effect of temperature on the pesticides toxicity. So, spinosyins should be applied in cold weather, whereas, abamectin and emamectin benzoate performed well in relative high temperature. [ABSTRACT FROM AUTHOR]

Carboxylesterases are enzymes widely distributed within living organisms. In insects, they have been mainly involved in dietary metabolism and detoxification function. Interestingly, several members of this family called carboxylesterase-like adhesion molecules (CLAMs) have lost their catalytic properties and are mainly involved in neuro/developmental functions. CLAMs include gliotactins, neurotactins, glutactins, and neuroligins. The latter have for binding partner the neurexin. In insects, the function of these proteins has been mainly studied in Drosophila central nervous system or neuromuscular junction. Some studies suggested a role of neuroligins and neurexin in sensory processing but CLAM expression within sensory systems has not been investigated. Here, we reported the identification of 5 putative CLAMs expressed in the olfactory system of the model pest insect Spodoptera littoralis. One neuroligin, Slnlg4-yll and its putative binding partner neurexin SlnrxI were the most expressed in the antennae and were surprisingly associated with olfactory sensilla. In addition, both transcripts were upregulated in male antennae after mating, known to modulate the sensitivity of the peripheral olfactory system in S. littoralis, suggesting that these molecules could be involved in sensory plasticity. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Using Diatomaceous Earth in form of Silica nano-particles to control the cotton leaf worm, Spodoptera littoralis (Boisd.) larval stage was tested. The obtained results clarified that the application of silica in nano-form at any of the tested concentration reflected adverse effects on the treated larvae. Feeding larval stage of S. littoralis on castor bean leaves, treated with Silica nano-particles, reduced growth rate, decreased efficiency in exchanging consumed food into body biomass, and decreased larval weight. In addition, the obtained low efficiency of conversion of ingested food (ECI) and/or efficiency of conversion of digested food (ECD) values were observed at the tested concentrations of (1, 2 or 4%), where its consumption leading to retardation in the development, prolongation in the duration and finally death. [ABSTRACT FROM AUTHOR]