Effect of Processed kaolin clay (WP 95%) on Cotton Whitefly, Bemisia tabaci Gennadius

Cotton whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is one of the most important pests of cotton which reduces the quantity and quality of the product. Several different synthetic insecticides have been used to control whitefly by farmers. To reduce the use of chemical insecticides, application of kaolin particle film was tested in cotton farms in Kashmar region in Khorasan Razavi province. Different concentrations of kaolin clay (Sepidan® WP 95%) (3 and 5%) and Thiacloprid෩浪枭蚸 insecticide (Proteus® OD 110) (1000 ppm) were sprayed two times over the whole canopy of cotton at 3–4 week intervals from August to October. Based on the field studies, kaolin (5%) application reduced the whitefly nymphs population and deterred ovipositionat all spraying stages. The mortality percentage for whitefly nymph, in 3 days after spraying, were 67.2±2.9, 87±1.3 and 18.1±4.5 for kaolin (3%), kaolin (5%) and Proteus treatments, respectively. The percentage of oviposition deterrence, in 3 days after spraying, were 36.4±5, 57.4±3.5, and 53.5±2.2% for kaolin (3%), kaolin (5%) and Proteus treatments, respectively. Also, control ability for whitefly nymph and oviposition deterrence for psylla, up to 21 days after spraying,inkaolin treatments were appropriate compared with chemical insecticide treatment, so that, the efficacy percentage on nymph were 30.9±3.6 and 35.1±3.6 and the rate of oviposition deterrence were 92.6±1.6 and 38.3±5.5%, in the kaolin (5%) and Proteus treatments, respectively. Therefore, kaolin (Sepidan® WP 95%) spray over the whole canopy of cotton (5% concentration), could be used successfully to reduce whitefly nymph and its oviposition on cotton.