Identification of volatile organic compounds of pistachio trees and their role in attraction of common pistachio psyllid, Agonoscena pistaciae (Hemiptera: Aphalaridae)

The common pistachio psyllid (CPP: Agonoscena pistaciae) is the key pest of pistachio orchards in Iran. At the moment, insecticides despite their known adverse effects on human health and environment, are the only and the last option for controlling CPP in most cases. However, selection pressure of insecticides has resulted in establishing highly resistant populations of CPP. Nowadays, volatile organic compounds (VOCs) of plants presenting opportunities for sustainable plant protection. In this regard, VOCs of pistachio trees (Ohadi and Kaleh ghoochi cultivars) were collected by headspace method in the pistachio orchards and identified chromatographically (GC–MS). VOCs, including monoterpenes, esters, acids, alcohols, aldehydes, and aromatics, were identified in both cultivars, numbering 43 in the Ohadi cultivar and 37 in the Kaleh ghoochi. The quantitatively dominant constituents were (E)-β-Ocimene (32.5%), limonene (14.8%) and methyl benzoate (12.1%) in the Ohadi cultivar and (E)-β-Ocimene (29.2%), limonene (20.1%) and α-Thujene (6.6%) in the Kaleh ghoochi. To study whether olfactory cues elicit responses in adult CPP, the odor of pistachio leaves (Ohadi cultivar) were offered in a Y-tube olfactometer to field-collected populations. Significant positive responses to volatiles of leaves were found in both males (P<0.03) and females (P<0.001). These data may be useful in semiochemically-based management strategies in the pistachio orchards such as mass trapping or deter of CPP or attraction of natural enemies.