Effect of varietal diversity in olive groves on the population of leopard moth, Zeuzera pyrina L. (Lepidoptera: Cossidae)

• Esmat M. Hegazi1 and Wedad E. Khafagi2
• ¹ Faculty of Agriculture, Alexandria University, Egypt.
• ² Plant Protection Research Institute, Sabahia, Alexandria, Egypt.

Abstract

The leopard moth, Zeuzera pyrina L. is a polyphagous inset pest that attacks more than 70 shrub species belonging to over 30 botanical families including olive. It seriously attacks both young and old olive trees and presents continuous threat for olive farming on almost all olive growing areas in Egypt. The damage caused by Z. pyrina larvae has already led to uprooting of many olive groves in Egypt. Infestation rates by Z pyrina of a large olive farm (ca. 450 feddans) of young and fruitful olive trees (61774 trees) of nine table olive varieties were studied for 2 successive years. The farm is divided into 88 uniform plots (5-7 feddans, each). Each plot is surrounded by windbreak trees (Casuarina sp.) isolating each plot from the others. Each plot contains 2, 3 or 5 olive varieties of total 780-900 trees/plot. All trees of 24 plots were carefully inspected at the peak period of adult emergence of leopard moth. The results suggest 3 categories of olive varieties: 1) sensitive (Toffahi, Becual, Sennara and Manzanilla); 2) intermediate (Kalamata, Doice and Aks); and 3) resistant (Hamedy and Shamy). Interestingly, the co-existence of one olive cultivar may decrease or increase the rate of infestation by Z. pyrina larvae. The study may provide information about colonization of the leopard moth on specific olive variety in multiple varietal cropping olive farm system. Discovery of allomones in resistant varieties which drive away egg laying of Zeuzera females may be fruitful in protecting the sensitive olive varieties, i.e., olive farms from the leopard moth.