Mohammadali Mirhosseini

The pistachio psyllid, Agonoscena pistaciae Burckhardt & Lauterer, is one of the most destructive pests of pistachio trees in Iran. This study evaluated the efficacy of five chemical compounds including abamectin (EC 1.8%), acetamiprid (SP 20%), hexaflumuron (EC 10%), hexaflumuron (EC 10%) + abamectin (EC 1.8%), and thiamethoxam (SC 24%) at concentrations of 0.6 ml/L, 0.25 g/L, 0.7 ml/L, 0.5 + 0.3 ml/L, and 0.4 ml/L, respectively. The insecticides were applied at two different timings: early control (second week of May) and late control (fourth week of June) in two pistachio orchards in Isfahan Province, Iran. Nymphal mortality was recorded one day before spraying and at 3, 7, 14, and 21 days post-treatment. In both application times, thiamethoxam and abamectin exhibited the highest and lowest insecticidal efficacy, respectively. The early control was more efficient than the late control in all treatments. Therefore, early application of thiamethoxam is recommended for optimal chemical control of pistachio psyllid.