Allelochemicals response of Citrus sinensis L. cv. Washington navel against Ceratitis capitata Wied, 1824 (Diptera:Tephritidae) in Tlemcen region, Algeria

We studied the relationship between the Citrus sinensis ripe fruits secondarymetabolites and the Mediterranean fruit fly (medfly), Ceratitis capitata. The understanding ofthe fruit-insect interaction mechanism is required to develop pests control strategies. Thequantitative analysis of polyphenols by UHPLC and GC-MS showed very high concentration offlavonoids (0.292 +/- 0.009; 0,197+/- 0.008 mg CE/g D.M.) and tannins (0.126 +/- 0.005,0.086+/- 0.004 mg CE/g D.M.) in fruits attacked by sterile and fertile sting than in healthy fruits.UHPLC analysis detected new compound at retention time of 7.307 in fruits attacked by thefertile stings. The GC-MS analysis identified the phenolic compounds: (I). 2-Propenoic acid, 3-(4-hydroxy-3-methoxyphenyl) (17,195%), (II). 2-Methoxy-4-vinylphenol (11.620%),(III).Benzaldehyde, 3-methyl (3.281%); Ethanone, 1-(3,4-dimethoxyphe) (2.129%), fatty acids:(I). 9,12-Octadecadienoic acid (Z,Z) (6.446%), (II). Ethyl 9,12-hexadecadienoate (4.052%), (III).n-Hexadecanoic acid (1.855%) and an alkaloid Heptanediamide,N,N’-di-benzo (12.792%).