Exposure of freshly laid eggs of Exorista bombycis(Louis) to volatiles emanating from bulbs Allium sativum L. for different durations resulted in significant reduction in their hatchability. Maggots hatched from the eggs exposed for 64 h and 72 h were failed to emerge from host larvae. The duration of developtal stages pof E. bombycis was prolonged besides reduction in rate of pupation and adult emergence as the egg exposure period increased. The findings are interpreted as the chronic effects of volatiles of garlic affecting maggots fnllowing developmental defects sustainable during embryonic development. The known major chemical components of A. sativum such as allicin, thioacrolein, ajoene, 2-propene sulfenic acid, 2-propene thiol and propylene were presumed to be responsible for the adverse consequences reported in this paper.