Seasonal Activity and Damage Caused by Leopard Moth, Zeuzera pyrina L., in Walnut Orchards, Chaharmahal va Bakhtiari Province, Iran

Seasonal flight of the adults, larval activity, and damage caused by Leopard moth, Zeuzera pyrina L., was studied in the walnut orchards in Chaharmahal va Bakhtiari province, Iran. Pheromone baited traps were set up in the studied orchards from May 10 (before the emergence of adult males) to July 15 (the end of the adults' flight) to monitor the flight dynamics. Observation on development of different stages of the pest was done weekly throughout the growing season. The infestation ratio of twigs and number of active galleries per tree were recorded at studied locations. According to the results, the pest completed its life cycle within a year and overwintered as 4th and 5th instar larvae inside the galleries in trunk and main branches of walnut trees. The flight season of Z. pyrina started in the second decade of May, the peak occurred in the first decade of June, and the flight ended by the second decade of July. Eggs were laid individually next to the buds on the twigs and 1st instar larvae tunneled directly into inner wood. The maximum damage in shoots and twigs was observed at the third decade of August and, thereafter, larvae gradually moved to the main branches and trunk. Results showed that the biology and seasonal flight pattern of Z. pyrina in this province are different from other infested areas and that may be because of the climate condition. The knowledge of the observed differences may be useful to develop a successful integrated management strategy against Z. pyrina.