RESPONSE OF CERATITIS-CAPITATA TO CITRUS CHEMICALS UNDER SEMINATURAL CONDITIONS

Responses of Mediterranean fruit fly Ceratitis capitata (Wiedemann) (D iptera: Tephritidae) adults to chemicals from citrus fruits were quant ified in choice tests conducted in large held cages housing naturally planted orange trees, on the Greek island of Chios. Both sexes respond ed strongly to chemicals released from artificial cuts made in the pul p of peeled oranges and also to natural or commercial orange juice app lied to the surface of yellow 7.0 cm diameter spheres. Males also resp onded strongly to chemicals released from cuts made in the oily region of the orange peel, or flavedo and less to sour orange and lemon. In contrast, females did not respond to flavedo chemicals. Male response to peel chemicals occurred throughout the day and increased as the num ber of cuts per fruit increased from 2 to 8. Contact of male mouthpart s with sap from cuts, and mating attempts between males on or near the cuts were frequently observed. The males also responded to commercial essential orange oils applied to yellow spheres, but less to essentia l mandarin oils. The role of citrus chemicals in host finding behaviou r of C. capitata and their potential use for the development of effect ive traps for monitoring and controlling the Ay are discussed. The exp erimental method followed in this study can be used as a standard tech nique for evaluation of the quality of flies to be used in sterile ins ect technique programmes.