Abstract :
This paper presents the results of phytochemical screening of plant extracts obtained from taxodium, erythrine, melaleuca, and terminalia plant species for chronic toxicity and larval growth inhibition in the cotton leaf worm, Spodoptera littoralis. the photochemical screening of the tested plants investigated that carbohydrate was identified as the major compound in Taxodium distichum , Terminalia arjuna , Melaleuca cajuput while flavonoids, flavonoid glcosides ,flavonols, Chalcones, tannins, sterols and/or triterpenes and alkaloids or nitrogenouswere found to be the second main compounds in Taxodium distichum but the second main compounds in Terminalia arjuna and Melaleuca cajuput were flavonoids,flavonols, tannins ,sterols and/or triterpenes and alkaloids or nitrogenous. On the other hand, Terminalia arjuna was rich with saponins. The insecticidal properties of the tested plants extract each in ethanol and chloroform was evaluated at the concentrations of (10 to 0.625%). There was a positive correlation between the concentration and the percentage of larval mortality and malformed pupae and adult. All the concentrations showed significant differences in mortality of Spodoptera littoralis as compared to control. The reduction in F1 progeny, elongation of the larval duration, and pupal period at any of the tested concentrations were noticed. There was a moderate gradient reduction in the pupation percentage of the different treatments compared with control treatment. Moderate fluctuation observed among sex ratio. Percentage of adult emergence and growth was inhibited with increasing the concentrations as observed in four plant extracts compared to control.
Keyword :
plant extract/ Spodoptera littoralis; ethanol extracts; Aqueous extract; photochemical screening