EFFICACY OF DISULFOTON FOR CONTROL OF GREEN PEACH APHID MYZUS PERSICAE ON PEPPERS

In a 3-year study, one annual application of a 10% granular formulation of disulfoton in the soil at a rate of 2 lb actual toxicant per acre controlled M. persicae throughout the entire period that aphids were most prevalent in pepper fields. Some control was observed within a few days of treatment, but effective control did not occur until 2 to 3 weeks after placement of the insecticide. Irrigation increased the initial uptake of disulfoton, but after 2 weeks the degree of control was essentially the same in irrigated and nonirrigated plots.Analyses of fruit samples from treated plots showed that there were no detectable amounts of disulfoton or its oxidation products 42, 50, and 60 days after treatment. These observations suggest that the required interval of 90 days between treatment and harvest could be reduced. Appreciable amounts of the insecticide or its oxidation products were present in the leaves on all sampling dates. © 1969, Entomological Society of Canada. All rights reserved.