Seasonal Presence of White Fly Species on Jujube Trees in Nineveh Governorate

Abstract

The study was conducted in the gardens of Mosul University from September 2019 to September 2020 in order to determine the types of white flies that infest Jujube trees and their seasonal activity. The results showed that Jujube trees, Zizyphus spina Christi, were infected with the following species: Acaudaleyrodes rachipora (Singh), Aleurolobus marlatti (Quan), and Aleuroclava jasmini (Takahashi). The percentage of leaf infection was highest in November, followed by September and August with an average 98.95, 94.85 and 94.63%, respectively. The insect preferred upper surface of the leaf than its lower surface, as the average number of nymphs was 15,11, and 1,39 nymphs/leaf, respectively, and the number of nymphs peaked during the autumn months. Direction had no effect on the rate of leaves infection, and no significant differences appeared between the treatments, while the density of nymphs in the leaves was affected by the direction factor, as the southern direction was significantly superior at a rate of 18.85 nymphs/leaf, and no significant differences were recorded between the other three directions. The results of the weekly catch also showed that the density of adults ranged between (1.28-168) adult /trap, peaking in October, while the adult were absent from the traps during January and February. Some predators were seen preying on the stages of the white fly, Lasiochilus pallidulus (Reuter), Oenepia conglobate (L.), Chrysoperla carnea (Stepheus).