Pest fruit flies (Diptera: Tephritidae) are commonly monitored using female attractants and synthetic male lures placed in traps. The male lures commonly used in Hawaii: cue-lure to attract melon fly (Bactrocera cucurbitae) and methyl eugenol to attract Oriental fruit fly (B. dorsalis), are traditionally believed to be specific to fruit flies. Past studies have suggested that a small number of non-target organisms, including some native species, may be attracted. Protein baits, on the other hand, attract a diversity of non-target organisms, and should be used with caution near habitats hosting native species. At least 195 arthropod species have been collected in traps baited with one or another attractant or lure, though few of them were declared as records of significant attraction. Furthermore, at least some of the past records of significant attraction to male lures were actually due to attraction to dead flies accumulating in traps and not the lures. The study underway is investigating attraction and effects of methyl eugenol, cue-lure, proteinaceous attractants (solulys, Torula yeast), and Biolure 3-component lure for Mediterranean fruit fly (Ceratitis capitata) control, on non-target organisms. We are monitoring traps along ecological gradients ranging from native forests, mixed forests, and secondary forests, to agricultural farmlands and residential areas. The ultimate goal of this study is to generate recommendations on the use of various fruit fly baits for control of pests in a way that minimizes the risk of attracting native and beneficial arthropods.