Relative toxicity of selected insecticides against adult whiteflyBemisia tabaci (Hemiptera: Aleyrodidae) transmitting Mesta yellow vein mosaic virus

Abstract

Whitefly (Bemisia tabaci) is an important pest of more than 600 host plant species and vector of various plant begomovirus. Bioassay of five insecticides namely, imidacloprid 200 SL (Confidor), flonicamid 50 WG, (Ulala), spiromesifen 240 SC, (Oberon) diafenthiouron 500 SC (Pegasus) and dimetheoate 30 EC (Tafgor) were tested against adult whitefly of kenaf crop. These insecticides gave adult whitefly mortality in ranged of 30 to 88, 22 to 60, 25 to 65, 28 to 75 and 20 to 50 per cent respectively under controlled laboratory conditions after 24 hours treatments. Among the insecticides studied, imidacloprid was found most toxic (LC50-6.6 ppm) to adult whiteflies followed by diafenthiouron (LC50-22.59 ppm). Similarly, the insecticides flonicamid (LC50-24.85 ppm) and spiromesifen (LC50- 28.37 ppm) possess toxic against whitefly but dimetheoate (LC50-7100 ppm) was found least toxic. On the basis of LC50 values, imidacloprid was found most toxic to adult whiteflies followed by diafenthiouron and emerged as best insecticides for managing the whiteflies.