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The functional and structural features of microbial load in soil are influenced by the presence of insecticides. This study examined the impact of two organophosphorus insecticides, dimethoate and parathion on the microbial load of soil. The colony count of fungi, actinomycetes, bacteria, and nitrogen fixing bacteria was reduced after insecticides application at 7 and 14 days, but at 28 days the colony count began to increase. The growth of two white rot fungi including Pleurotus sajor-caju and Phanerochaete chrysosporium was affected by parathion, which was reflected by a decrease in colony radius to 1.85±0.05 and 0.75±0.06 cm, respectively, and by dimethoate, reflected by a decrease in colony radius to 3.33±0.12 and 1.85±0.05 cm, respectively at 40 mg/L compared to colony radius at control 7.90±0.12 and 7.50±0.06 cm, respectively. The applied low concentration (10 mg/L) encouraged P. sajor-caju and P. chrysosporium to remove up to 87.7% and 81.8% of dimethoate, respectively, and 69.20 and 68.30% of parathion, respectively compared with the decomposition at high dose (40 mg/L) at 28 days. The presence of insecticides induced the production of ligninolytic enzymes lignin peroxidase, laccase, and manganase peroxidase. [ABSTRACT FROM AUTHOR]

Background: Nowadays, the fall armyworm, Spodoptera frugiperda (J.E. Smith) FAW, is the most *destructive crop pest invading maize in different countries. Objective: This study holds significant implications for the field of pest management. It aims to assess the efficacy of crude algal extract of Chlorella vulgaris and Bacillus thuringiensis strain against the 2nd and 4th larval stages of the fall armyworm, a pest currently causing significant damage to maize crops. Methods: A rigorous research process was followed, using serial concentrations of bioagents to determine the mortality percent and LC50 values via a feeding technique. Results: Regarding the effect on the biological aspects, LC50 values were fed to the 2nd and 4th larval instar. In addition, histological investigations were checked. The results indicated that the high mortality percents were 90% and 60 % at the concentrations of 20000 ppm of algal extract, recording LC50 values of 10027.42 and 15805.06 ppm for the 2nd and 4th larval instar, respectively. Furthermore, bacterial strains induced 100% and 60 % mortality at the concentrations of 1000 ppm with LC50 values of 232.50 and 883.46 ppm for the 2nd and 4th larval instar, respectively. Moreover, feeding these compounds caused alterations in the mid-gut tissue and disturbances in the life cycle of the fall armyworm. Conclusions: The algal extract and the bacterial strain have demonstrated a significant toxic impact on the fall armyworm and could be involved in the integrated management protocol of this pest. [ABSTRACT FROM AUTHOR]

Background: The fall armyworm, Spodoptera frugiperda, poses a significant threat to over 90 plant species, causing extensive damage by consuming fresh leaves, hindering growth, and ultimately reducing crop yields. Integrated pest management strategies emphasize eco-friendly approaches, minimizing harm to non-target organisms. Among these, biological control methods, including the use of plant extracts and specific microorganisms, have shown considerable efficacy in controlling the fall armyworm. Methods: This study assessed the impact of neem seed oil extract and CuO & ZnO nanoparticles on the biological aspects of Spodoptera frugiperda. Fourth-instar larvae were exposed to fresh castor leaves treated with neem seed oil extract, obtained through Soxhlet extraction from neem seeds, and nanoparticles prepared via direct precipitation. Results: The determined LC50 values of neem seed oil extract, ZnO, and CuO NPs against the 4th instar were 500, 520, and 440 ppm, respectively. All treatments had an impact on the durations of larval and pupal stages, resulting in increases of 66% and 15% with neem seed extract, 11.5% and 15% with ZnO, and 21.7% and 23% with CuO. Additionally, pupation rates were reduced by 50% following exposure to neem seed extract and ZnO, and by 45% with CuO nanoparticles. It is also worth noting that the digestive enzymatic activities in the insects were significantly affected following treatment with the LC50 values of neem seed extracts and nanoparticles. Conclusion: The study demonstrates the potent larvicidal properties of both neem seed extract and nanoparticles against Spodoptera frugiperda. All treatments effectively prolonged larval and pupal stages and reduced successful adult emergence at low concentrations. All treatments also showed a negative effect on the enzymatic activity of insects, which indicates their potential as natural insecticides in combating fall armyworm. [ABSTRACT FROM AUTHOR]

Recently, algae have attracted the attention of investigators as a renewable source of compounds that can contribute to nanoparticle creation. The use algae biomass to facilitate preparation of copper oxide nanoparticles (CuONPs), as well as their application, were the aims of the present study. High performance liquid chromatography analysis of algal biomass indicated the presence of daidzein (2550 µg/mL), followed by ellagic acid (596 µg/mL). Algal biomass extract was successful as a bioreducing agent for CuONPs fabrication at different temperatures up to 50 °C. Transmission electron microscopy characterized the created CuONPs with average size 5 to 17 nm. The colony radius of M. anisopliae, T. harzianum, C. lunata, F. oxysporium, A. flavus, and A. terreus was 1.84 ± 0.08, 1.97 ± 0.03, 1.00 ± 0.08, 2.04 ± 0.03, 2.32 ± 0.06, and 2.42 ± 0.05 cm, respectively at 200 mg of CuONPs. CuONPs exhibited inhibition zones of 26, 23, 25, and 22 mm when tested against B. subtilis, E.coli, K. pneumoniae, and S. aureus, respectively. Methyl orange and methyl green dyes were degraded by CuONPs with percentages ranging from 9.5 to 63.7% and from 22.3 to 75.7% at 15 to 90 min, respectively. Therefore, the created CuONPs can be regarded as excellent candidates for controlling fungal/bacterial development and dyes degradation. [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.)

Effects of Buxus chinensis extract, Bacillus thuringiensis and nuclear polyhedrosis virus (NPV) mixture on certain biological aspects of Spodoptera littoraUs were studied against the 2nd and 4th larval instars of S. littoralis. The mixture of the three compounds was the most toxic against the 2nd and 4th instar larve, where it caused high percentage of mortality, while 8. thuringiensis (Dipel 2x) and nuclear polyhedrosis virus (NPV) mixture induced a slight effect against the 2nd and 4th instars. Regarding the ethanolic extract of Buxus chinensis leaves, it was more effective than 8. thuringiensis (Dipel 2x) or nuclear polyhedrosis virus(NPV) in respect of pupal mortality and larval, pupal and adult duration. This plant extract also reduced the fecundity and fertility of females emerged from the treated larvae of S. littoralis. [ABSTRACT FROM AUTHOR]

Bacillus thuringiensis strains that belong to B. thuringiensis, B. kurstaki and soil-isolated B.t. were assessed in the following phytopathogenic: Rhizoctonia solani, that had their mycelial growth decreased after incubation in the presence of the bacterial strains. The bacteria have also pathogenic effect against the insect pest Spodoptera littoralis. The isolate B.t. D-l and the B.t. kurstaki HD-203 were found to be inhibiting R. solani, the strain B. kurstaki HD-203 displayed the highest percentage of inhibition (64%) and B.t. D-l showed 49% of inhibition. Antagonistic activity was maintained up to pH 8.5, and the antifungal activity was stable to heat at 70 °C for I h. Minimal inhibitory concentrations were 152 and 131 μl/ ml for B.t. D-l and B. kurstaki HD-203, respectively. The two strains also have high efficacy against S. littoralis larvae, B.t-D1 gave 70% and the B. kurstaki HD-203 strain gave 80% mortality after seven days of treatment. [ABSTRACT FROM AUTHOR]

The influence of soil pH, moisture, temperature and indigenous microorganisms on the survival of Bacillus thuringiensis (local isolate) in different soil types was investigated. The pathogenicity of this isolate was determined using Spodoptera littoralis (Biosd.) larvae. The highest reduction in the number of spores present as CFU, in soils having different pH values was during the first two weeks post treatments, and then almost stabilized for the next weeks. The important factor affecting spore survival was the soil pH (soil type). The highest and lowest reductions in the spore numbers were shown with soils at pH (5.1) and pH (7.2) respectively. The pathogenicity fell rapidly until reached < 5 % after 8 weeks post treatment which may be due to that, the crystals were degraded far more rapidly than spores. There were no important effects on spore numbers under various moistening degrees, different temperatures or the indigenous microorganisms of all soil types. [ABSTRACT FROM AUTHOR]

A total of 14 isolates of Bacillus thuringiensis were obtained from 25 soil samples collected from 5 Governorates in Egypt. The isolates were identified according to morphological features and physiological characteristics such as; anaerobic growth, fermentation of glucose, Voges-Proskauer reaction, protein hydrolysis, citrate utilization as a sole source of carbon and reduction of nitrate. From 68 selected colonies having Bacillus-form, 14 were able to produce bipyramidal crystals, forming white, rough colonies, spread out and expand very quickly over the plate. Growing under anaerobic conditions, produced acid from glucose, hydrolyzed gelatin, reduced nitrate, utilized citrate and gave positive reaction for acetylmethyl carbinol test. Such results proved that, these 14 isolates belong to Bacillus thuringiensis. [ABSTRACT FROM AUTHOR]