A Field Evaluation of Malathion Dust for the Control of Body Lice

During the period January 9 through March 6, 1961, a field evaluation was conducted at a Republic of Korea Army prison farm near Seoul, Korea, to determine the efficacy and safety of 1% malathion dust used to control body lice (Pediculus humanus humanus L.). One ounce of dust applied either semimonthly by hand or monthly by power duster gave virtually 100% control, while monthly applications of the same dosage of 1% lindane powder gave poor control. Lice from the test subjects were resistant to DDT but susceptible to lindane and malathion as determined by laboratory tests. Physical examination and weekly red blood cell cholinesterase determinations revealed no adverse effects from malathion dust used on 200 test subjects. The discrepancy between laboratory and field results as they apply to lindane is discussed.