I. Immunogenic killed vaccine against African horsesickness can beprepared from a neurotropic vaccine strain of virus type 3, grownin MS cell line. Virus was inactivated with hydroxylamine in afinal concentration of 0.01 M at 37°C. In order to enhance theimmunogenicity of the vaccine, aluminium hydroxide gel wasadded as an adjuvant.After inocculation of a single dose of the vaccine, CF .Ab,HA.Ab, and SN .Ab developed within 4 weeks in inocculated horse,and when the second booster dose was injected after 4 weeks, muchhigher anti-bodies were present in sera after eight weeks post firstinjection.2.The use of SIR -8514 insecticide in controlling C. pipiens, succeed-ed under laboratory conditions and it was effective against thedifferent larval instars and pupae of C .pipiens .(Lab. strain) in thedilution 10-5 as it caused 100% reduction in emerged adults, whilein controlling the pupal stage of ~.pipiens (wild strain) the dilult-ion 10-3 of the investigated insecticide was effective as it caused99% reduction in emerged adult. Moreover I the investigatedinsecti cide was found to affect the fecundity of tested females ofC .pipiens as well as the longivity of both males and females of theemerged adults previously treated in the pupal stage with differentdi lutions of the insecti cide.