Attraction and feeding responses of oriental fruit ßy, Bactrocera dorsalis (Hendel), and melon ßy, Bactrocera cucurbitae (Coquillett), were determined for different protein baits. In separate choice attraction assays for each species, signiÞcantly more ßies arrived at stations with bait than water, but no differences existed among baits of GF-120 Fruit Fly Bait, GF-120 NF Naturalyte Fruit Fly Bait, Provesta 621 autolyzed yeast extract, and Mazoferm E802. In comparison with B. dorsalis, B. cucurbitae had 2.8 times more responders and a 4.8 times better discrimination between baits and water. In a second attraction assay with only B. dorsalis, volume of bait was negatively correlated to numbers of ßies alighting on the bait. Feeding assays for both species demonstrated that time spent feeding and duration on a leaf were both signiÞcantly affected by bait type. B. dorsalis fed the longest on Provesta 621, with signiÞcantly less feeding on the other baits, and with all baits resulting in more feeding than water. The longest feeding times for B. cucurbitae resulted with Mazoferm E802 and Provesta 621, and all baits except GF-120 NF resulted in eliciting a signiÞcantly longer feeding duration than water. In separate toxicology assays for each species, signiÞcantly higher mortality resulted from bait formulations containing spinosad compared with blank baits, but no differences existed between GF-120 and GF-120 NF formulations. The differences are discussed between the two Bactrocera species primarily in regard to bait preference, extent of response, and previous work on laboratory ßies.