The lethal, sublethal and some physiological effects of crude latex of Sodom apple, Calotropis procera 9Alton) were assessed using the third instar larvae of the greater wax moth, Galleria mellonella (L.) as a model insect species. Latex showed LC₅₀ of 37 μl latex/g diet after 48 hours of feeding on latex incorporated artificial diet. Larvae were continuously fed, until pupation, with artificial diet containing LC20 of latex. Feeding inhibition and accumulated larval mortality of 53 .0 ± 15% and 73 ±2.6%, respectively, were observed before pupation for the LC₂₀ fed larvae. The incorporation of C. procera latex into the diet significantly prolonged the larval stage duration and decreased larval and pupal weight than untreated larvae.  Furthermore, latex significantly reduced relative consumption rate (RCR), relative growth rate (RGR) and efficiency of conversion of ingested food (ECI). While there were no significant effects of latex on activities of both invertase, and esterases (α and β Esterases) it showed a strong and significant inhibitory effect on α–amylase.  However, latex induced an obvious and significant increase in alkaline phosphatase activity. It is suggested that the antifeedant effect of C. procera latex could be due to the digestion inhibition through the inhibition of α–amylase activity, while a significant portion of the digested food were used by C. procera latex fed larvae for synthesis alkaline phosphatase. These results provide more evidences regarding the mode of action of the lethal and sublethal effects of C. procera latex on G. mellonella.as a model insect species.