Susceptibility of Two Olive Varieties Aldeibli and Alkhudairi to Olive Fruit Fly Bactrocera oleae (Gemlin) (Diptera: Tephritidae)

This study was carried out in the western region of the Homs province (3440' N, 3645' E) in 2010 to determine the susceptibilities of two varieties Aldeibli and Alkhudairi to olive fruit fly Bactrocera oleae. The results showed two major periods of fly activity, the first period extended from June to mid-August, while the second fly period started the last week of September and ended during harvest period in middle October. The first infection signs appeared on the Aldeibli variety in the third week of June. The average fruit length, diameter, weight and oil content were: 1.59 0.97 cm, 1.2 0.06 cm, 1.7 0.29 g and 1.76 0.11% respectively. Percent infection starts to rise during the third week of August and this rise was accompanied by an increase in the length, diameter, weight and oil content of the olive fruit. Correlation coefficients concerning the fly activity in relation to fruit injury and epicarp hardness of the variety Aldeibli was negative (epicarp hardness was 57.08 4.83 g with the start of infection and 54.51 6.08 g with the end of the first period). In contrast, observable infection symptoms in the Alkhudairi variety did not appear during the first period of fly activity. Significant differences observed between the two varieties concerning the average fruit length, diameter, weight and oil content. Epicarp hardness of Alkhudairi variety 65.33 0.06 g was higher than the Aldeibli variety 56.73 0.19 g. Infection symptoms on Alkhudairi variety started to rise with the beginning of the second fly period. In contrast in the Aldeibli variety no new symptoms were observed. Average of fruit length, diameter and weight of Aldeibli was higher than that of Alkhudairi variety and no significant difference were observed concerning oil contents between the two varieties. Significant differences between the two varieties were observed concerning epicarp hardness, color of fruits Index Jaen of pigmentation.