EN
The effect of 20 new hydrazine derivatives on Musca domestica was determined by topical application method. As standard hydrazides of the cyanoacetic and isonicotinic acids as well as hexochlorocyclohexane (BHC with isomer γ contents 99-100%, m.p. 112-113°) and dichlorodiphenyltrichloroethane (DDT, m.p. 107-109°) produced by Chemical Plants "Azot" Jaworzno were used. It was stated that among 20 new compounds only 5 acted as insecticides on adult M. domestica individuals viz. N-cyanoacetyl-N'-hippurylhydrazine, phenylhydrazide of methyl ester of succinic acid, phynelhydrazide-N-propylamide of succinic acid, o-nitrophenylhydrazide of isonicotinic acid, p-bromophenylhydrazide hydrochloride of isonicotinic acid (Table 3). Their action on the third - rate larvas of M. domestica was evaluated by modified Gliwic method; determinations were repeated twice with three different compound concentrations, the mortal doses 50% were calculated according to Kadłubowski. It was found that larva-killing effect showed the o-nitrophenylhydrazide of isonicotinic acid only; lindane acted on larvas a little weaker. None of investigated new or standard compounds showed egg-killing activity (Table 3). Special consideration deservs the o-nitrophenylhydrazide of isonicotinic acid in spite of its weaker activity on adult M. domestica individuals than DDT, it is remarkably less toxic for vertebrates (white mouse LD₅₀ = 403 ± 25 mg/kg), its larva-killing action is more stronger than that of lindane.