در استان گيلان EUPHYLLURA OLIVINA COSTA بررسي بيواكولوژي پسيل زيتون

Bio-ecological studies on the olive psylla, Euphyllura olivina Costa (Rom., Aphalaridae) in Guilan province

A Bioecological study of the olive psylla were investigated in two olive groves during three successive years and in the laboratory condition. Olive psylla overwintered as adults on the olive trees and mate in mid March and females start to egg laying at first into the buds of old branches, then deposited on the terminal buds, and at ultimately between the calyx and corolla of flower buds. Individual females deposited an average of 5I.4±2.7 eggs from late Match up to May. The nymphs started to appear in early April and lasted until mid July, and adults of spring generation emerged in late May. Olive psylla has one generation per year and spring generation adults spent the summer, autumn and winter on the olive trees with a reproductive diapause. The host preference studies showed that there is significantly difference between varieties (P<0.1), and psylla prefer Roughani variety more than others. Sex ratio of males to females was about 1.1:1 in both Roudbar and Loshan regions. Psylla nymphs were parasited by species of Pteromalidae and Encyrtidae. Coccinellid predators, lacewings, hover flies and spiders were observed feeding upon the eggs, nymphs and adults. In addition to, the cold winter might have an effect on the mortality of overwintering adults and reduce the olive psylla population.