OVICIDAL ACTION OF CERTAIN CHITIN SYNTHESIS INHIBITORS IN MOSQUITOS

Ovicidal action and delayed effects of three chitin synthesis inhibitors, diflubenzuron, penfluron and Bay SIR 8514 were studied in mosquitoes, Culex quinquefasciatus, Aedes aegypti, Anopheles stephensi and An. culicifacies. Penfluron was found to be most effective as an ovicide against the eggs of Ae. aegypti and An. culicifacies while diflubenzuron proved to be better than other compounds against Cx. quinquefasciatus and An. stephensi. Freshly laid eggs were more susceptible to the chemicals as compared to older eggs. Treated eggs showed abnormal hatching. All the compounds at higher concentrations caused delayed effects such as increased larval mortality and very low adult emergence.