The toxicity of three synthetic compounds namely (Diazinon, Phorate and Carbaryl) against eggs, immature, young mature and adult stages of L. luteola was studied. A comparison between the effects of the three compounds against eggs of 0-24 h old of L. luteola revealed that the three compounds gave low ovicidal effect on the base of LC₅₀ and LC₉₀ values. While, Carbaryl gave more effective than Phorate then Diazinon  came in the last category against eggs and immature stages of L. luteola according  to the LC₅₀ also, Phorate gave more effect than Carbaryl then Diazinon came in the last category against young and mature stages of L. luteola according the LC₅₀ vapues. The slope values indicated that the insect population had the same homogeneity in their response to both Phorate and Carbaryl, while it had less homogeneity in case of Diazinon  for the tested stages of L. luteola.