Determination of damages of pistachio twig borer moth Kermania pistaciella Amsel, to fruit clusters of pistachio trees.

摘要

The pistachio twig borer moth, Kermania pistaciella Amsel, 1964 (Lepidoptera: Oinophilidae: Oinophilini), has been a major and important pest in pistachio orchards in Iran. Some quantity and quality damages of pistachio twig borer moth were studied in pistachio orchards in Rafsanjan condition. The adult moth appears in late March-early April, lays its eggs in flower and fruit clusters, as well as on new shoots and petioles during high pest populations. The newly hatched larvae directly penetrate into the cluster tissues from which they bore into the rachis fruit cluster. Larvae tunneled in the pedicel of fruit cluster and branches and began to feed. There are four larval instars in pistachio woodborer life cycle. Different larval instars could be separated by measuring the width of head-capsule and pronotum. At harvest time by visual observation, 100 fruit clusters with larval tunneling and 100 intact fruit clusters were randomly collected in 4 replications from orchards of Kalleh-ghoochi pistachio cultivar. In both fruit clusters with larval tunneling and intact fruit clusters, number of total nuts, split nuts, blank and non full growth kernel nuts, and irregular hull cracking pistachios per clusters were measured. Results showed that, the pistachio twig borer moth causes severe economic damage through fruit dropping, decreasing quality and quantity of crop yield and rachis weakening of fruit clusters. Number of nuts per cluster, and split nut percentage significantly decreased in fruit clusters with larval tunneling in comparison with intact fruit clusters. In contract, irregular hull cracking pistachios, blank and non full growth kernel nuts significantly increased in fruit clusters with larval tunneling in comparison with intact fruit clusters.