INSECTICIDAL PROPERTIES OF SOME PLANT EXTRACTS AGAINST COTTON LEAFWORM Spodoptera littoralis (BOISD)

Authors

1 Inst. Plant Prot. Res., Cent. Agric. Res., Egypt.

2 Dept. Plant Prod., Fac. Environ. Agric. Sci., Arish Univ., Egypt.

Abstract

Laboratory experiments were conducted under controlled conditions to test the insecticidal activity of aqueous and organic extracts of different solvents (ethanol and acetone) of nine plants collected from North-Sinai (Mint,Menth piperita L.; Clove, Syzygium aromaticum L.; Camphor,Cinnamomum camphora L.;Tree tobacco,Nicotiana glaucaG.; Syrian Rue, Peganum harmala L.; Artemisia monosperma L.; Chinaberry, Melia azedarach L.; Egyptian henbane,Hyoscyamus muticus L. and Calotropis, Calotropis procera L.) against 4th  instar larvae of cotton leafworm(Spodoptera  littoralis  Boisd).The results showed that the aqueous extracts C. camphora L. gave the highest toxicity among all tested plants with LD50 equal to 152 ppm and M.piperita L. recorded the lowest toxicity with LD50 equal to 500 ppm. The toxicity index (T.I) was the highest value (100) in case of C.camphora L. and the lowest value was (30.6) in case of M.piperita L. The relative potency (R.P) showed the highest value equal to 327.2 with C.camphora L, while the M.piperita L. showed the lowest value equal to (100). In case of using organic (ethanol alcohol) extracts the results showed that the ethanolic extracts of S.aromaticum L. has the highest toxicity with LD50 equal to 76.9 ppm and that of C.procera L. has the lowest toxicity with LD50 equal to 205.6 ppm . The toxicity index (T.I)of S.aromaticum L. have the highest value (T.I) (100) and the C.procera have the lowest value T.I (37.4). The relative potency (R.P) was the highest in S.aromaticum L. (267.4) and the lowest (R.P) was in C.procera (100) .Finally by applying the organic (acetonic) extracts, the results, showed that acetonic extracts of S.aromaticum L. recorded the highest toxicity with LD50 equal to 44.4 ppm while acetonic extracts of C.procera L. showed the lowest toxicity with LD50 equal to 100.6 ppm. The highest (T.I) was with S.aromaticum L. value (100) and the lowest (T.I) was observed in case of C.procera (44.1) recoded. The relative potency (R.P). Was the highest in case of S.aromaticum L.(226.6) ,while the lowest (R.P) was in case C.procera(100).

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