Biology and damage of the pistachio twig borer on four commercial pistachio cultivars

The pistachio twig borer moth, Kermania pistaciella Amsel (Lepidoptera: Oinophilidae) is one of the key pests of Iranian pistachio that annually causes high damage by penetrating and feeding the larvae from the branches. In this study, and to determine the damage percent and control appropriate time, from the middle of February onward, 200 labels were randomly attached in pistachio orchards with varieties of Akbari, Ahmad Aghaei, Kalleh Ghuchi and Ohadi in the eastern countryside of Rafsanjan in late February. The number of emerged larvae and formed cocoons were recorded every two days. The amount of pest damage on the four important commercial cultivars was determined by counting the larval outlet holes, cocoons, the percentage of contaminated seeds at harvest time, and the number of dried grains at the end of the panicle. The results showed that there was no significant difference between the peak times of adult moth’s emergence in different cultivars. Fifty percent of pupae were formed in the last days of the first decade of April. In the middle of the third decade of this month, adult insects emerged. Also, the average damage of the pistachio twig borer moth was highest (40.44%) in Kalleh Ghuchi and lowest (34.15%) in Ahmad Aghaei. The highest amount of damaged grain belonged to Kaleh Guchi cultivar and the lowest to Oohadi cultivar. Overall, the results of this study indicate that cultivar has no significant effect on the pest biology. This finding could be used in forecasting of pest status and determination of the control time.