Study the kaolin powder efficiency in reducing the Asian citrus psyllid, Diaphorina citri (Hem.: Liviidae) population

Asian citrus psyllid Diaphorina citri Kuwayama (Hem: Liviidae) is one of the most destructive citrus pests in tropical and subtropical regions. Asian citrus psyllid is a sap-sucking insect and could act as a vector for the serious citrus greening disease. Vector suppression is critical to reduce disease spread. In this research, the effect of kaolin powder was investigated on control of citrus psyllid in a randomized complete block design with 3 treatments including 3, 5 and 7% kaolin powder in Kerman province, during 2011 and 2012. The different concentrations were sprayed over the whole canopy of trees. Results showed that the percentage of the mortality of adults in the two years at concentration of 3%, 5% and 7% suspension of Surround WP ranged from 23.24 - 48.09, 53.47 - 85.49 and 62.23 - 88.34%, respectively. Efficacy of 3, 5 and 7% suspension of Surround WP on citrus psyllid oviposition resulted in reduction of 22.86 - 49.69, 65.49 - 91.74 and 73.99 - 96.72%, respectively. The results showed that during two years of experiment, there was no significant difference between the two Kaolin treatments at 5 and 7%. Therefore, spraying citrus trees with processed kaolin, at a concentration of 5%, could significantly reduce the damage of the citrus psyllid.