Control tests of adult flies, their larvae and mosquito larvae by malathion

Abstract

Field tests of the control of adult flies, their larvae and mosquito larvae by malathion were done during 1 June to 28 July, 1955, in Yokaichiba, Chiba Prefecture, Japan. The results were summarized as follows : By the spray of 27 to 42cc of 0.5% emulsion or 0.7% kerosene solution of malathion per square meter on the ceilings of the dwellings, the fly population estimated by traps set in dwellings decreased remarkably and the effect lasted for 7 to 10 days. To fly larvae in latrines, the application of 2 liters of 0.1% emulsion or 100g of 1.5% dust of malathion was effective, but the larvae emerged again 7 days after the application. The fly larvae in manure heaps could be controlled by spraying 10 liters of 0.02% malathion emulsion per square meter, though the spray of 2 liters of 0.1% emulsion was almost ineffective. The difference in the effect of applying the same amount of the active ingredient may be ascribed to the permeability of the chemical into the heaps. The application of 100cc of 0.2% malathion emulsion per square meter was effective to mosquito larvae in water tanks or small ponds, though almost ineffective to the pupae of the mosquito.