Screening Some Non-Phosphorous Insecticides Against Adult Greenhouse Whiteflies Tolerant to Organophosphates

Abstract

The non-phosphorous insecticides pyrethrin. lindane and fenvalerate were tested against a population of greenhouse whitefly tolerant to some organophosphorous chemicals. Pyrethrin was the most effective insecticide followed by lindane. The former was 10 times more toxic than lindane, while the dosage of fenvalerate should be twice as much as that of lindane to obtain 49% mortality. The LC50 values for pyrethrin, lindane, and fenvalerate were 0.004, 0.042 and 0.092 respectively. These chemicals also varied in their slope values. They were 1.34, 0.84 and 0.28 respectively. These insecticides are recommended for the control of tolerant whitefly because they proved to be 66, 6.6, and 3.0 times, respectively, more toxic than malathion.