Biology and population dynamics of pistachio leaf borer Ocneria terebinthinea (Lep: Lymantriidae) in pistachio orchards

Pistachio white leaf borer, Ocneria terebinthina Stgr. (Lep.: Lymantriidae) is one of the minor pests of pistachio in Iran. Some morphological characters and biology of the pest were studied in two orchards in Anar and Kerman,Iran. Ten pistachio trees (15-20 years old) and 60 leaves of each tree were selected from four different directions and visited twice a week. The eggs and larval emergence was recorded and cocoon formation was located. Seasonal occurrence of adults was recorded using light traps.. Our results revealed that pistachio white leaf borer, passes the winter as larval instar under loose bark on the trunk of pistachio trees or in white cocoons beneath plant litters. Activity of the overwintering larvae usually starts from the late March. Prepupal formed on the host leaves or bark crevices on infested trees. The adults appear in pistachio orchards in early spring (males appear earlier than females). Females lay eggs in batches on both the upper and lower surfaces of the pistachio leaves. The number of eggs in a single batch could be 4.75 to 361. This pest have 3 generations in Anar-Iran. In early autumn, the third instar larvae move toward diapausing shelters, molt to the fourth instar, make a whitish silk cocoon, and enter diapause. Overwintering larvae terminate diapauses at theend of winter and start feeding. Life cycle of the pest was also studied at two different temperatures i.e. 25±2 and 30±2°C, %65±5 humidity and 14L: 10D h photoperiod. Results indicated that there was a significant difference between life cycle of the pest in these two temperatures (p<0.01). The longest period of development belonged to seven larval instar and the shortest to prepupal stage in both temperatures.