Abstract
Toxicities of the mixture of cadmium (Cd) and ethylenediaminetetra acetate (EDTA) on the Bombyx mori larvae fed on artificial food in aseptic conditions was investigated. The mixture was given to the various developmental stages of larvae and the rates of growth or mortality of the larvae were examined after 10 days of administration.
1) When the 200 ppm Cd was given, the mortality rate of larvae approached 100% on each stage.
2) When a mixture of 200 ppm Cd with 0.04 M of EDTA was given, the development of larvae was almost usual and no dead larva was observed.
3) When a mixture of 320 ppm Cd with 250 ppm Zinc (Zn) was given, still dead larvae were observed. When a mixture of 5, 000 ppm Cd with 0.04 M of EDTA was given, all tested larvae in the first instar were dead, but the survival rate of 10% in the third instar and of 40% in the fifth instar larvae were observed respectively. It was confirmed that a mixture of Cd-EDTA is more effective to decrease on the toxicity of Cd than that of Cd-Zn.
