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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 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]

Fourth instar larvae of cotton leafworm,Spodoptera littoralis(Boisd.), fed on castor bean leaves treated with sub-lethal concentrations of both alcohol and hexane extracts of Egyptian conyza and Challenger 36% SC insecticide as well to study their effects on mortality, food consumption and utilisation of food. The tested insecticides exhibited relatively high mortality in alcoholic extract of Egyptian conyza (5.0% concentration) followed by Challenger (1.0% concentration). Results showed a slight reduction in the consumption index for larvae treated with both alcoholic extract and Challenger at low concentrations, while hexane extract (5%) recorded significant increase. The approximate digestibility (AD) was reduced in all treatments of alcoholic extract and the relative growth rate insignificantly decreased at 5% concentration, whereas AD increased for larvae fed on Challenger 0.25% concentration. The lower concentration of alcoholic extract of conyza and all treatments of Challenger pesticides induced insignificant decrease in the efficiency of conversion of the ingested food, while hexane extract exhibited insignificant increase. Challenger at all tested concentrations achieved insignificant decrease in the efficiency of the conversion of digested food with respect to the control. [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 ability of some isolates ofBacillus thuringiensisto produce dark brown pigment was measured as an indicator to UV resistance. M5as an indigenous Egyptian isolate was used as wild type to improve its resistance to UV. It was exposed to UV irradiation for different periods ranging between 1 and 10 h. The induced mutants were examined morphologically by phase contrast microscope. One hundred and forty four mutants were obtained; 10 of them were selected and tested for their toxicity againstSpodoptera littoralis. The results showed that mutants 62, 65 and 85 were the most toxic ones. These three mutants and the wild type were examined by transmission electron microscope. Crystal proteins with bipyramidal shape and active against Lepidopteran insects were detected in all the selected mutants. [ABSTRACT FROM AUTHOR]

Laboratory experiments were conducted to assess the efficiency of the new strain CCM 8367 ofIsaria fumosoroseaon different stages of the Egyptian cotton leafworm,Spodoptera littoralis(Boisd.), including soil treatments with pre-pupal and pupal stages. Treatments of larval instars showed a high susceptibility with 3rd, 5th and last instars to suspension of this fungus with concentration 5 × 107spores/ml. Larval mortality was over 90%. There were no significant differences (P = 0.7929,F = 0.2346) between instar treatments. The commercial fungus, PreFeRal® strain Apopka 97 ofI. fumosorosea, which was used in comparison with this new strain caused mortality rates of between 63.33 and 90%. Statistically, differences between the effects of CCM 8367 strain and Apopka 97 were highly significant on the last instar (P = 0.0064,F = 6.479) and extremely significant on the 3rd instar (P < 0.0001,F = 13.29). No significant differences were recorded between the two strains on the 5th instar (P = 0.0597,F = 3.233). Fungal treatments with the late stage insects (end of the last instar or pupal stage) in soil yielded interesting results: the mortality rate on end of final instar larvae was 16.66% when treated with Apopka 97 and 83.33% when treated with CCM 8367. Soil containing pupae ofS. littoralisthat were inoculated with CCM8367 resulted in a high number of malformed adults, and the mortality rate was 64.52% (32.27% of malformed adults died and 32.25% of pupae fully infected by fungus). Only 3.23% of samples produced morphologically normal adults in this test. The results conclude that the strain ofI. fumosoroseaCCM 8367 has strong insecticidal effects onS. littoralisand has the potential to be implemented as a novel biocontrol agent. [ABSTRACT FROM AUTHOR]

Ethanolic extracts of larval frass of the cotton leaf worm and the black cutworm were prepared and tested to deter the eggs lay of the adults of the same insects. Two different types of food were used for larval feeding. Extracts fractions were identified using gas chromatography–mass spectrometry analysis. High concentrations were more deterrent to oviposition than low. Extracted frass of fed larvae on semi-artificial diet was more effective than others fed on natural host. Sensitivity of the black cutworm adult females to the cotton leaf worm frass extract was clearly observed at high tested concentration of L1–3and L4frass extracts which resulted completely oviposition deterrent. Several fatty acids were identified qualitatively and quantitatively in frass extracts of different larval instars of both target insects. Type and quantity of fatty acid depends mainly on larval food source and larval instar, except palmitic acid which recorded at all larval instars and food sources. Oleic acid and ethyl 9-hexadecaenoic acid were found when semi-artificial diet used as a food source while myrisitic acid was observed only in extracted frass of fed larvae on castor oil leaves. [ABSTRACT FROM AUTHOR]

The present study scrutinised how far temperature would affect the velocity of the insecticidal activity of Bacillus thuringiensis, as the rapidity of pest control achievements is of a great concern. Third instar Spodoptera littoralis larvae were treated with Bt at three concentration levels under five different temperatures (15°C, 20°C, 25°C, 30°C and 35°C). LT50s were evaluated in each case. The LT50 values showed various levels of reductions as temperature and/or Bt concentration increased, indicating that the velocity of mortality (1/LT50) and/or the rapidity of Bt activity was almost temperature dependant. However, relatively high and low reduction percentages in the LT50 values on the elevation of 5°C were obtained at lower and higher temperature ranges, respectively. The temperature coefficient, Q 10 values, determined within narrow ranges (5°C) showed great reductions when temperature increased from 15°C to 20°C at all Bt concentrations. Raising temperature by 5°C above 20°C or 25°C almost caused similar Q 10 values indicating constant increase in the response of Bt activity within 20–30°C temperature range. Q 10 values over 30°C were comparatively very low. This proved that decrease in Q 10 values due to the rise of temperature was dependant on the starting temperature. [ABSTRACT FROM PUBLISHER]

The biological activities of two species of bacteria isolated from soil of cotton fields identified as Bacillus subtilis strain NRC313 (BS NRC313) and Bacillus thuringiensis strain NRC335 (BT NRC335) were evaluated against the third larval instar of the cotton leafworm, Spodoptera littoralis (Boisd.). The different entomopathogenic bacteria of BS NRC313and BT NRC335 contained 10 × 108 cell/ml, and caused mortality of 100 and 97.3% for the above mentioned strains, respectively. Concentrations of 2.5 × 108 to 10 × 108 cell/ml of strains BS NRC313 and BT NRC335 were applied to the larvae: LC50 were 3.3 × 108 and 3.9 × 108 cell/ml respectively. The influence of exposure to toxin concentrations manifested in terms of decreasing the adult emergence and prolongation of the generation period. The percentage of larvae that survived and succeeded to pupate increased by decreasing the concentration. The longevity of adult emergence that resulted from larvae treated with Bacillus subtilis were 6.0 ± 0.51 and 9.0 ± 0.63 days at 5 × 108 and 2.5 × 108 cell/ml, respectively compared with 9.8 ± 0.47 in control. The results indicated that Bacillus subtilis was more potent than Bacillus thuringiensis. Field applications of B. thuringiensis, B. subtilis and Reldan achieved 55.6, 67.4 and 89.4% reduction of the cotton leafworm larvae Spodoptera littoralis in clover plants under field conditions. [ABSTRACT FROM AUTHOR]

Egg masses laid by Spodoptera littoralis mated female moths were extracted by petroleum ether (PE), ethanol (E) and Ringer's solution (RS). Egg-wash extracts were evaporated and the weights of crude materials were obtained. Different aqueous concentrations were made. The amount of extracted material increased as the weight of eggs used increased and vice versa. Coating Nerium oleander leaves with aqueous egg-wash extracts prepared from S. littoralis egg-masses deterred the mated conspecific female moths from ovipositing their eggs on treated leaves, as well as causing a decrease in the total number of deposited eggs per female during the moth's life span. The highest deterrent effect on conspecific female moths to oviposit their eggs was obtained after treatment of N. oleander leaves with PE or E egg-wash extract. The deterrent effects of the tested egg-wash extracts was concentration dependant; an increase in the concentration of any extract caused an obvious decrease in the number of deposited egg-masses and the total number of laid eggs on the treated N. oleander leaves. [ABSTRACT FROM AUTHOR]

The effect of Artemisia monosperma wild plant hexane extract on some biological and physiological aspects of Spodoptera littoralis, as well as some biochemical and histopathological changes after treatment with this extract have been studied. The results indicated that treatment with larvae for two days revealed satisfactory effects in larval mortality (50%) and in larval weight and prolonged the effect in the pupal stage. Also the treatment reduced the food consumption and the amount of faeces of the tested larvae which led to a significant reduction in the final body weight with 76.4%. Treatment also extended the time of food passage through the midgut to 3.2 h compared to 1.38 h in control, and the larvae had a smaller midgut. The enzymatic activity of the digestive enzymes amylase and invertase revealed a significant inhibition in the treated larvae. Also transaminase enzyme activity (AST and ALT) reduced after treatment. The results of phosphatase enzyme activity (ACP and ALP) showed a potent inhibitory effect on both enzymes which more was pronounced in ALP than ACP activity, the percent inhibition being 73.8% and 30.6%, respectively. The histopathological effects of A. monosperma treatment on the midgut of Spodoptera littoralis revealed that the epithelium membrane was exfoliated and completely destroyed. Meanwhile, epithelia cells were strongly vacuolated and considerably elongated. Boundary lines between the cells disappeared. [ABSTRACT FROM AUTHOR]

The daily reproductive rate of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) fed with Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) larvae was studied at constant temperatures of 20, 23, 25, 28, 30 and 33±0.2°C, relative humidity of 60±10% and photoperiod of L:D 14:10. Daily reproductive rate of P. nigripinus was affected by age of this predator. Each P. nigrispinus female laid 5.3 (20°C) to 19.9 eggs/day (28°C) which developed into 4.3-16.5 nymphs, respectively. Highest daily reproductive rate of P. nigrispinus was recorded at 28 and 30°C for 5-30-day-old females. This predator showed higher daily reproductive rate than its prey A. argillacea at 25°C. It was also able to reproduce at temperatures from 20 to 33°C with maximum daily reproductive rate between 25 and 30°C. These results are important for optimizing mass rearing of P. nigrispinus in the laboratory. [ABSTRACT FROM AUTHOR]

Diets consisting of leaves of cotton and/or water were insufficient to promote the complete development and survival of Podisus nigrispinus (Dallas) to the adult stage. However, nymphs fed leaves lived longer than those provided with only water. Addition of Alabama argillacea (Huebner) larvae to the diet of P. nigrispinus added a substantial increment to the survival during the nymphal stage. The addition of cotton leaves to the diet of P. nigrispinus nymphs promoted an increase in the weight of newly eclosed adults, independent of predator sex. In addition, diets supplemented with cotton leaves promoted an increase in the duration of the oviposition period, the number of egg clutches per female, and the number of eggs per female. No effects were noted on either the duration of the pre-oviposition period, the number of eggs of the first clutch, the number of eggs per clutch, the interval between egg clutches, or sex ratio. Feeding on plant material by P. nigrispinus is a potentially positive attribute in biological control against cotton leafworm. [ABSTRACT FROM AUTHOR]

Effects of the botanical extract (myrrh), Commiphora molmol, and thesublethal treatments of profenofos/chlorofluazuron, fenvalerate and pyriproxyfen on the larvae of S. littoralis were investigated. The results showed that myrrh induced the highest activity after 7 days of treatment with concentration of 10000 ppm and the percentage of mortality reached 44.4%. The chemical insecticide profenofos/chlorofluazuron appeared to be the most effective treatment, giving a mortality of54% after one day of treatment with a concentration of 100 ppm. Different treatments showed adverse effects on pupation, emerging adults and larval duration. The highest concentration of myrrh (10000 ppm) induced 35% pupation. No pupa was obtained with profenofos/chlorofluazuron while fenvalerate and pyriproxyfen gave 13.3% at 50 ppm. At 10000 ppm of myrrh, 25% adult was emerged, also fenvalerate and pyriproxyfen decreased the emerging moth to 13.3% at 50 ppm. For control therewas no larval mortality at 7 days and the percentages of pupation and adult emergence were 90%. Bioassays were also conducted to test thejoint action of myrrh applied in binary mixtures with each chemical insecticide on Spodoptera larvae. Results of the bioassay of mixturesindicated antagonistic effects on larval mortality. However, combination of myrrh with pro fenofos/chlorofluazuron showed additive effect. Also, the degree of pupation and emerging moth varied considerably when myrrh combined with the chemical insecticides. The present work shows the strong efficacy of the botanical extract (myrrh) which could be used alone or in combination with sublethal doses of certain insecticides to control the cotton leafworm. [ABSTRACT FROM AUTHOR]