Carob moth Ectomyeloisceratoniae Zeller is the most dangerous pests of dates in Algeria. This species is polyphagia, its wide distribution in space and on various hosts make chemical control the most using in palm grove without success. Under these conditions, only the biological control may be able to limit the damage of this pest and reduce the negative effect of chemicals on the environment and fauna life in palm grove. The study of azadirachtin effect on the mortality on the first larval stage revealed that the doses used were significantly and positively correlated with mortality corrected for different durations of exposure of larvae L1 to biopesticide (24 hours: r2= 0.872; 48 hours: r2= 0.906; 72 hours: r2= 0.905; 96 hours: r2= 0.880 and 120 hours: r2= 0.779). The higher LD50 (437.59 ppm) was recorded for a lethal time of 24 hours however the lowest LD50 (76.86 ppm) was observed for a lethal time of 120hours. We have also recorded a decrease in female’s fertility issue from larvae’s survived to the treatment withazadirachtin; with an average low lying eggs of54. 67ą19. 41 induced by the doseof 384 ppmand low hatching rate of eggs with 17.51 ą2. 94% occasion by the dose of 192 ppm, compared at thecontrolwith 159.67 ą 35.04 eggs laid and hatching rate with 94.96 ą2. 53%. Also thedosesusedwere significantly andnegativelycorrelated with thenumber of laidand hatchedeggs (r2= 0.755 and rē= 0.712 respectively).