*Corresponding author
New synthetic insect growth regulators, viz. 8-propargyloxy-3, 7-dimethyl-2, 6-octadienyl and 8-propargyloxy-3, 7-dimelhyl-6-octenyl ethers prepared from 8-hydroxy geranyl and 8-hydroxycitronellyl ethers, respectively, were evaluated for inhibition of metamorphosis and ecdysis in mosquitoes and some agricultural pests. Reduction in egg hatch and mortality in hatched larvae/nymphs was observed, resulting in substantial reduction of ultimate adult emergence. In Phthorimaea operculella, egg hatch was totally inhibited. Failure of egg hatch, larval mortality, formation of larval-pupal intermediates, albino pupae, pupal mortality and failure of adult eclosion were some of the effects on mosquitoes. Failure of egg hatch, moulting and adultoid formation were observed in case of Dys-dercus koenigii indicating juvenoid type activity.
