Laboratory Evaluation of Insecticides Applied as Sprays for Rice Leafhopper and Planthopper Control. IRRI Laboratory, 1977

Abstract

Abstract Two application methods were used to evaluate the various insecticides. In a contact toxicity study four replications of 25 insects each were treated in a Potter’s spray tower. Insecticides were applied on 2-day-old adult hoppers as 0.04% sprays in a volume of 2 ml and at a vaccum pressure of 0.71 kg/cm2. After treatment insects were placed in a 500 ml beaker containing 10-day-old rice seedlings. Mortality was determined at 48 hours after treatment. In a foliar spray test 12.5 ml of a 0.04% concentration of insecticide were applied on 45-day-old rice plants. This rate is equivalent to 750 g ai/ha. Four replications of 10 insects each were placedonthe plants at 1, 7, and 14 days after treatment. Mortality readings were taken at 48 hours after placing the insects on the plants. Both studies were at a temperature of 27 ± 1°C and mortality values were adjusted using Abbott’s formula. Insecticides having mortality ≥80% were considered effective.