Toxic Effects of Malathion and Endosulfan on Chick Embryo

Toxic effects of malathion and endosulfan to fertile chicken eggs were determined. In-jection of 1.25, 2.5, 5.0 and 10.0 mg/egg of malathion into yolk sac of fertile eggs prior to incubation caused mortality of 10.0, 30.0, 83.33 and 93.33% respectively. Similar trend was observed with injection of endosulfan doses. Malathion and endosulfan at 1.25 mg/egg caused no pronounced LD50 increase in mortality as compared to control groups. The LD50 values for these insecticides proved malathion to be more toxic than endosulf- an. The hypothesis that the dose response of viable embryo fitted a linear regression line was statistically acceptable. Combination of malathion and endosulfan increased the mor-tality rate as compared with either one alone. With either compound, an increased dose generally resulted in a decrease in embryonic body weight.