Toxicity and antifeedant effect of hexane apricot kernel extract (HEAK) and its gas chromatography-mass spectroscopy (GC-MS) identified fatty acid (FA) components palmitic acid (PA), Oleic acid (OL) and FA derivatives (Linoleic acid methyl ester (LAME)) were assessed against 2nd and 4th instar larvae of Spodoptera littoralis under laboratory conditions. Methoxyfenozide (Runner 24% SC®) was used as reference insecticide to (HEAK) and its components. The results were statistically analyzed by probit analysis to calculate (LC50) of mortality and the concentrations caused 50% of antifeedant index (AI50) after 24, 48 and 72 hrs of exposure. The results of toxic and antifeedant effects showed the definite prevalence of HEAK versus its FA components against the two instar larvae of S. littoralis throughout 72 hrs of exposure.  However the toxic initiation of the extract and its components paced methoxyfenozide by the first 24 hrs of exposure, methoxyfenozide still owned a superior toxicity and antifeedant response on the treated larvae. This work has been associated with some physiological tests including haemocytes count and corpora allata (CA) activity.