Reproductive and population parameters of melon flies, Bactrocera cucurbitae (Coquillett): oriental fruit flies, B. dorsalis (Hendel); Malaysian fruit flies, B. latifrons (Hendel); and Mediterranean fruit flies, Ceratitis capitata (Wiedemann) were measured at 16, 18, 24, 29, and 32 +/- 1 degrees C. Female longevity of B, cucurbitae, C, capitata, B, dorsalis, and B, latifrons ranged (minimum/maximum) from 35.6 to 136.5, 12.5 to 107.3, 27.5 to 133.5, and 15.0 to 80.3 d, respectively. Corresponding ranges for longevity of male fruit flies were 37.4 to 220.8, 13.3 to 182.0, 23.1 to 116.8, and 12.4 to 61.3 d, respectively. Highest net reproductive rates (i.e., production of newborn females per generation) for all species occurred at 24 degrees C. At this temperature, B, dorsalis rates were almost mice those for all other species. The rate of multiplication per generation per female was <1 for B. latifrons reared at all temperatures and for B. cucurbitae, B. dorsalis, and C. capitata at 16 and 32 degrees C. Highest intrinsic rates of population increase for all species were at 29 degrees C. Values at this temperature were highest for C, capitata and lowest for B. latifrons. Mean generation times varied inversely with temperature. The effects of temperature on fruit fly reproduction and life history patterns are discussed with respect to rearing operations and geography.