Evaluation of Dursban And Reldan, 1988

A laboratory study was conducted to determine sensitivity in two strains of German cockroach (University of Nebraska resistant and Orlando normal strains) to Reldan EC and Dursban EC. Ten male German cockroaches from each strain were anesthetized and 1 μ1 of insecticide was topically applied to the thoracic sterna of each cockroach. This procedure was repeated for each dose (100, 300, 500, 1,000, 1,500, and 2,000 ppm), the acetone controls, and for each insecticide. After topical application cockroaches were held in plastic Petri dishes under ambient conditions (23-25°C, 10:14 (L:D) photoperiod, 30-50% RH). Each strain-insecticide-dose combination was replicated 3 times. Percentage mortality (moribund cock-roaches were considered dead) was recorded 24 h after insecticide application. Dose response curves were constructed using probit analysis of mortality data, yielding mean LD50 values for each insecticide-strain combination.