SHAMIM A. CHOUDHARY
Abstract
Fenvalerate, a synthetic pyrethroid causes its effects in either sex of mutant Drosophila melanogaster when applied topically to newly emerged flies at a dose of 0.007 u1/100 ml food. However the recovery of fertility was recorded as the post-treatment days increased. In cross combinations, where either male or female or both were treated, egg laying was delayed by 4-16 days as Compared to control. Recovery of fertility was more delayed in set (ii) as compare to set (i) or set (iii) treated flies. Also the flies treated at emergence, remained effected for longer period than the flies treated at maturity. The net result was reduced number of eggs laid, decrease in hatchability and number of larvae due to either lack of vitellin for normal growth of possibly some deleterious effects of fenvalerate on embryogenesis (Choudhar), 2003). According to Clark and Rockstein (1964), changes occur in the structure and function of some systems of insect with age that may modify the enternal environment of the organism and its susceptibility to the reproductive potential.