Comparative demography of three Hawaiian fruit flies (Diptera : Tephritidae) at alternating temperatures

Reproductive and population parameters of melon flies, Bactrocera cucurbita e Coquillett, oriental fruit flies, B. dorsalis Hendel, and Mediteranean fr uit flies, Ceratitis capitata (Wiedemann), were measured in environmental c hambers maintained at temperatures of (mum:minimum:minimum) 24:13, 24:24, 2 9:18, and 35:24 +/- 1 degrees C. Alternating temperature regimes more reali stically approached the variation found in nature and produced higher param eters than an optimal constant temperature (24 degrees C). Intra- and inter specific comparisons were done with 4 separate generations of wild fruit fl ies reared on a common natural host. All species attained their highest int rinsic rates of population increase at 29:18 or 35:24 degrees C; C. capitat a exhibited the highest intrinsic rates of increase at all temperature regi mes. All species attained maximum net reproductive rates at 29:18 degrees C , in the order C. capitata > B. dorsalis > B. cucurbitae. The 35:24 degrees C regime caused reductions in net reproductive rates of all species, with B. dorsalis affected most strongly. Male longevity was greater than that of females for all species in all temperature regimes. Two distinctly differe nt life history patterns were evident: (1) early reproduction, short life s pan, and a high intrinsic rate of increase (C. capitala), and (2) later ons et of reproduction,longer life span, and a lower intrinsic rate of increase (B. cucurbitae).