Plainly the ideal approach would lie in finding agents that are high­ly specific in their effects on the metamorphosis, metabolic rate and re­production potentiality in order to determine the consequence of hor­mone deficiency and the role of this compounds involved in the inactivation of prothoracic gland. Beside the known action of BAY-SIR compound as anti-moulting agents and long persistence in the nature which exhibited strong inhibited effect on the metabolism during vitello­genesis and hence on reproduction potentiality which may be more ap­propriate when using as pesticide. On the other hand, pyriproxyfen compound induced pronounced sterility that induced over 99 % reduction in population and revealed sharply decrease for haemolymph total cholesterol. Therefore, it may have possible role as insecticide and /or chemosterilant.