ATTRACTION OF CERATITIS-CAPITATA (DIPTERA, TEPHRITIDAE) FLIES TO ODOROF COFFEE FRUIT

On potted nonfruiting host trees in outdoor field cages, we evaluated attraction of released mature laboratory-cultured or wild-origin Medit erranean fruit flies (medflies) to odor of freshly picked fruit of hos t and nonhost plants. Odor of ripe intact or crushed coffee fruit (the presumed ancestral host of medflies) was significantly more attractiv e than odor of ripe intact or crushed fruit of five lower-ranking host s and three nonhosts. Odor of crushed coffee fruit was significantly m ore attractive than odor of intact coffee fruit. Odor of ripe or near- ripe coffee fruit was significantly more attractive than odor of unrip e coffee fruit. Immature females (without eggs) were significantly mor e attracted to odor of a proteinaceous food lure than to odor of ripe coffee fruit, whereas the reverse was true for mature females carrying a high egg load. In some trials, males proved as discriminating as fe males in favor of coffee fruit odor, but in several other trials males were less discriminating than females. Response patterns of mature la boratory-cultured females were similar to those of mature wild-origin females. In a field of coffee plants, attraction of natural-population females was significantly greater to odor of ripe coffee fruit than t o water but was not greater than attraction to odor of proteinaceous f ood. Findings are discussed in relation to potential use of synthetic volatiles of coffee or other host fruit in traps for monitoring or con trolling medflies.