FOOD BAIT ENHANCEMENT OF FRUIT MIMICS TO ATTRACT MEDITERRANEAN FRUIT-FLY FEMALES

In field experiments conducted in a citrus orchard in Chios, Greece, we compared, by direct observations, the response of the Mediterranean fruit fly, Ceratitis capitata (Wied.) (Dipt. Tephritidae) to citrus fruits and leaves and to fruit and leaf mimics (plastic, 7 cm diam. hollow yellow spheres and 10 x 15 cm yellow rectangles resp.), with and without 10 droplets of Nulure, a proteinaceous food lure. We found that on orange trees yellow spheres provided with Nulure were the most attractive to both sexes, and attracted more females than males. They were about three times more attractive to females than those without lure and about seven times more attractive than ripening orange fruit. We also found that prepunctured hollow yellow spheres containing an aqueous solution of 9% Nulure and 3% borax were five times more attractive to females than the same sphere without Nulure when hung on food-poor mandarin trees but only slightly more attractive when hung on food-rich fig trees. Our findings suggest that combining food odor and visual stimuli can considerably enhance the attractiveness of fruit models to C. capitata. Such a prepunctured fruit mimic, further enhanced by the addition of host odors, can probably find important applications for medfly management and control and for collecting eggs from wild medfly females to estimate egg fertility in programs involving the release of sterile males.