Estimation of secondary compounds content of some citrus leaves and their relationship by dietary preference for yellow scale insect Aonidiella. Orientalis (Hemiptera: Diaspididae)

Abstract

The yellow scale insect Aonidiella orientalis is an important pest of citrus trees as it absorbs sap from leaves and fruits, causing leaves to turn yellow and deform fruits and drop them. The results of study showed nutritional preference of the insect over some of studied citrus species, as sour orange was the most preferred, followed by lemon and grapefruit, mandarin and oranges were least preferred, with a rate of 22.3, 13.3, 11.7, 10.8, 3.9, and insect / 2 inch2, respectively. while results showed a difference in the content of citrus leaves from the secondary compounds, with highest concentration of phenols and total flavonoids in orange leaves compared to the lowest concentration in grapefruit, the highest concentration of alkaloids was in sour orange compared to the lowest concentration in lemons. highest concentration of total terpenes was in lemon and the lowest concentration was in orange, as for concentration of Lemonic acid, the highest concentration was in lemon leaves, and the lowest was in grapefruit, sour orange, mandarin and orange, respectively. The results also showed that Ascorbic acid in citrus gave the highest concentration in sour orange leaves, and the lowest was in lemon, grapefruit, mandarin and orange, respectively.