الفعالية المميتة لمستخلصات ثمار الفلفل الأسود ضد يرقات دودة ورق القطن

الملخص EN

This study was conductedto test the lethal effect of ethanol ,ethyl acetate, hexane and oil extracts of black pepper fruits Piper nigrum on the larval stageof cotton leaf worm Spodopteralittoralis.Inthis study the secondand sixth instar larvae were treated topicallyby using the concentrations of 1.25, 2.5 and 5% of each extract.The results of topically treatment for second larvae stage with different extracts showed a significant increase in the mortality , rates which ranged between 23.3% - 49.5% as in average of all used conc.

while the rates ranged between 6.1%- 11.1% for the sixth larvae and the highest mortality percentage caused by ethanol extract, which reached to 59.2% and 13.3% for the second and sixth instar larvae respectively, when % 5 conc.

was used, The results also pointed prolonged durations of both larval and pupal stages, depending on the conc.

used in the test ,ethyl acetate extract causean increase in thelongestperiod ofgrowthbothstage.