الفهرس 
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Abstract
Spodoptera littoralis is one of the most dangerous pest’s that affects many vegetables. This encouraged scientists to seek about substances of special importance in different aspects. e.g., agriculture, medicine and industry. 1. Life history traits: The results indicated that: 1. Incubation period with cucumber leaves didn’t change, however, larvae fed on tomato and potato leaves resulted in significantly higher incubation period compared to castor leaves. 2. The developmental periods of the 1st instar were 2.3, 2.3, 2 and 2 days due to feeding on tomato, cucumber, potato and castor leaves, respectively. 3. The 2nd larval instar, the developmental periods were 2, 2.3, 4 and 1.7 days post feeding on tomato, cucumber, potato and castor leaves, respectively. 4. The developmental periods of 3rd larval instar were 2, 2.8, 2 and 3 days, respectively with the four host plants. 5. For 4th larval instar, the developmental periods were 2.5, 2.2, 3 and 3 days with tomato, cucumber, potato and castor leaves, respectively. 6. For 5th larval instar, the average developmental periods were 1.5, 2.5, 1.7and 3 days for the four types of food, respectively. 7. The developmental periods of 6th larval instar were 2, 2.5, 2 and 1.6 days with tomato, cucumber , potato and castor, respectively. 8. The pre-pupal stage lasted 0.9, 1.6,1 and 0.7 days for larvae fed on tomato, cucumber, potato and castor leaves, respectively. 9. The pupal duration lasted 4.3, 3.7, 4.4 and 2.3 days with the same four host plants. 10. The total duration of immature stages was 21.5, 22.9, 25.1 and 20.3 days for tomato, cucumber, potato and castor leaves, respectively. 11. The pre-oviposition period lasted 1.8, 1.7, 2.2 and 2 days for female S. littoralis fed as larvae on tomato, cucumber, potato and castor leaves (as standard), respectively. 12. The female ovi-position period was 3.2, 3, 4.3 and 3.8 days for moths fed as larvae on tomato, cucumber, potato and castor leaves, respectively. 13. The post ovi-position period was 1.2, 1.2, 1.8 and 1.3 days due to feeding larvae on tomato, cucumber, potato and castor leaves, respectively. 14. Longevity of female was 6.2, 5.9, 8.3 and 7.1days for moths fed on tomato, cucumber, potato and castor leaves, respectively. 15. Longevity of adult male was 3.9, 4.5, and 6.1 and 4.9 days for moths fed on tomato, cucumber, potato and castor leaves, respectively. 16. The number of deposited eggs was 170, 280, 180 and 480 with tomato, cucumber, potato and castor leaves, respectively. 2. Life tables: Data showed that, the net reproduction rate (Ro) was 918, 3780, 1215 and 3240 within a single generation on leaves of tomato, cucumber, potato and castor, respectively. In conclusion, the calculated biological parameters (RO, GDT, rm and ƛ ) indicated that, cucumber leaves seem to be a favorable host for development and multiplication of S.littoralis larvae, whereas potato leaves seem to be the least favorable host. 3. Nutritional indices: 1. Consumption index (CI) increased when 4th instar larvae fed on tomato leaves, cucumber leaves and potato leaves but decreased when 5th and 6th instar larvae fed on tomato leaves, cucumber leaves and potato leaves compared with larvae fed on castor leaves. 2. Relative growth rate (RGR) decreased in 1-day-old 4th instar larvae, 1-day and 2-day-old 5th instar larvae and the entire 6th instar larvae when fed on tomato and cucumber leaves but increased in 2-day-old in 4th instar larvae fed on tomato and cucumber leaves. While, larvae fed on potato leaves decreased RGR in 1-day-old 4th instar larvae, but did not change in 2-day-old 4th instar larvae. In contrast, the RGR increased in 5th instar larvae and it was significantly decreased in the entire 6th instar larvae compared with larvae fed on castor bean leaves. 3. Approximate digestibility (AD) increased in 4th instar larvae when fed on tomato and cucumber leaves but decreased in 5th and 6th instar larvae when fed on tomato and cucumber leaves compared with larvae fed on castor bean leaves. However, feeding on potato leaves increased AD in 4th, 5th and 6th instar larvae. 4. Efficiency of conversion of ingested food to biomass (ECI) decreased with 4th, 5th and 6th larvae fed on tomato, cucumber and potato leaves compared with larvae fed on castor bean leaves. 5. Efficiency of conversion of digested food to biomass (EDC) decreased with 4th, 5th and 6th larvae fed on tomato, cucumber and potato leaves compared with larvae fed on castor bean leaves. 4. Susceptibility of S.littoralis larvae to some bio rationale insecticides : The results indicated that, the highest concentration was 750 ppm for tomato, cucumber and potato leaves extracts and showed mortality 93.33, 90& 80%. However, the highest concentration of nano silica was 5000 ppm and caused mortality 46.67%. Moreover, chlofluazuron recorded 96.67% mortality at the highest concentration 300 ppm. 5. Medium lethal concentration (LC50) of some biorational insecticides against Spodoptera littoralis : Results indicated that chlorfluazuron was the most effective compound to larvae of S. littoralis, with LC50 of 44.53 and LC90 of 238.74 ppm. While the LC50 values of tomato plant extract, cucumber plant extract, potato plant extract and nanosilica were 97.95, 130.97, 204.07 and 13449.66 ppm, respectively. The LC90 values were 579.05, 952.95, 1769.78, 33861867.6 ppm, respectively for the same compounds, respectively. 6. Combined effect of plant extracts and magnetism: In tomato leave extract; the total mortality was 10, 23.33& 46.67 % after 10, 20& 30 min of magnetism, respectively. For potato plant extract, the total mortality was 6.67, 20 & 40% after 10, 20& 30 min of magnetism, respectively. While, the total mortality for cucumber extract was 3.33, 13.33& 36.67%, after 10, 20& 30 min of magnetism, respectively. 7. Combined effect of plant extracts and chlorofluzaron or nanosilica: The results indicated that, the highest co- toxicity factor (+80) was obtained in case of combining tomato leaf extract with chlorofluzaron, so, chlorofluzaron and tomato leaf extract were the first and second most toxic compounds tested. 8. Phytochemical analysis: The obtained results revealed that, nitrogen content was the highest in castor bean leaves followed by potato leaves then cucumber leaves then tomato leaves. However, potato leaves had the highest potassium content followed by cucumber leaves then tomato leaves then castor bean leaves. Likewise, castor bean leaves had the highest phosphorus content followed by cucumber leaves then tomato leaves and then potato leaves. 9. GC- MS analysis of plant extracts: GC/MS analysis detected 46 compounds in tomato leaves extract, Phytol was the most abundant compound (16.03%). However, GC/MS analysis detected 80 compounds in potato leaves extract, Hexadecanoic acid methyl ester was the most abundant compound (20.53%). While, GC/MS analysis detected 150 compounds in cucumber leaves extract and Phytol was the most abundant compound (19.50%). 10. Histological studies: 1. Midgut: Treatment of S.littoralis larvae with the LC50 of chlorfluzuron and tomato leaf extract showed very similar histological symptoms that caused vacuolation of circular muscle layers from each other. Epithelial cells lost their integrity. Peritrophic membrane was disrupted and the microvilli were lost. 2. Fat body: Treatment of S.littoralis larvae with the LC50 of chlorfluzuron revealed sever vacuolation of fat cells. The latter become netuore shaped. The membrane surrounding the fat cell masses was disrupted but treatment with tomato leaf extract showed numerous vacuoles in fat cells and lysis of fat cells. 3.Integument: Treatment of S.littoralis larvae with the LC50 of chlorfluzuron and tomato leaf extract showed the same histological symptoms that were disappearance of hypodermis and loosing the procuticle.