The egg hatchability of Spodoptera mauritia was studied by exposing freshly laid (0?24 h), following with (24-48h) and to (48?72 h) eggs to different concentrations (5?10-5 ? 1.0 ?M/?l) of juvenile hormone analogue (JHA), fenoxycarb. Dosage dependent response was observed after the treatment. The response was dependent on the age of eggs and also found higher doses resulted in maximum reduction in hatching. Treatments of eggs caused significant differences in egg mortality between control and treatments, with LD50=0.002 ?M, LD90=0.048 ?M and LD50=0.002 ?M, LD90=0.071 ?M for (0-24 h) and (24-48h) respectively. In the case of delayed treatment (48h-72h) eggs hatched as that of control. The result found that freshly laid eggs were more sensitive than those treated 2or 3days old eggs. Fenoxycarb applied eggs has delayed effects on postembryonic development. Here, we observed that the resulting larvae in earlier stages showed some effects such as increased larval duration, formation of intermediates and subsequent death. Therefore, JHA Fenoxycarb has great potency in suppressing the population by affecting hatchability of eggs of S mauritia, and thus provides a useful tool for pest management.