Petroleum ether and acetone extracts of the lberis amara seeds and Anfholyza
ae(hiopica scale leaves gave higher toxic activity against the 1 st than the 4th lnstar larvae of Spodopfera JitforaJis.
The application of petroleum ether extracts (10 & 5%) had the highest insecticidal effect against the 4th and 1st instar larvae of S. litforaJis, respectively. Also. acetone extracts (5, 2.5. 1.25, 0.625%) gave 100% mortality against the first larval instar, while, 10% concentration had the highest mortality against the fourth larval instar. In addition toxic compounds in these plants were extracts by two solvents, but acetone was more active than petroleum ether. The percentage of mortality was directly proportional to the concentration applied and to the period of exposure.
The application of extract (10%) of the two solvents of the two plant species gave the highest reduction in feeding of the fourth instar larvae on treated leaf discs. showing 91.70 and 86.64% antifeeding activity. It was generally concluded that plant extracts possessed antifeeding activity and this activity increased by increasing the concentration. The obtained results showed that Iberis amara and Anfholyza aefhiopica extracts are good candidates that could be considered in any IPM program for protecting cotton plants against the cotton leafworm. Further field experiments are needed to confirm these conclusions
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