Effect of kaolin clay (WP 95%) on grape leafhopper, Arboridia kermanshah Dlabola (Hem: Cicadellidae) in field condition

Grape leafhopper, Arboridia kermanshah Dlabola(Hemiptera: Cicadellidae), is the most important pest of vineyards in Iran, that by laying eggs in the leaf tissue, feeding on leaves and transmission of viral pathogens, weaken the trees and reduce the quality and quantity of grape production. To reduce the use of chemical insecticides, application of mineral compounds was tested in a vineyard in Khalilabad region (Khorasan Razavi Province), in 2015. Treatments included kaolin (5% concentration), sulfur WP (3000 ppm), sulfur dust, a mixture of kaolin and sulfur WP, phosalone insecticide (1500 ppm), and control (water spray), respectively. Spraying times including late April, early May and mid-July, Samplings were carried out one day before and 3, 7, 14 and 21 days after spraying. At each sampling time, the total number of leafhopper adults and nymphs on 5 leaves per tree were counted. Based on the field studies, mineral compounds application reduced the leafhopper population at all spraying intervals. The mean percentage of leafhopper population reduction was observed in treatments including kaolin, kaolin and sulfur mixture, phosalone insecticide, sulfur WP, sulfur dust and control in 3 days after spraying, 89, 86, 57, 25, 25 and 3 percent, respectively, and also in 21 days after spraying, 48 , 47 , 17 , 7 , 12 and 2 percent, respectively. Therefore, kaolin (Sepidan® WP), with 5% concentration, or kaolin and sulfur mixture spray over the whole canopy of trees could be used successfully to reduce leafhoppers population on grape.