life table gives the most comprehensive explanation of the survivorship, development, and reproduction of a population. the life table parameters of an aphidophagous midge, aphidoletes aphidimyza were studied on different densities (5, 10, 20, 40, 60, 80) of third instar nymphs of aphis gossypii as prey in a growth chamber (25 ± 1 °c, 70 ± 5% rh and a photoperiod of 16l: 8d h). the pre-oviposit...

demographic parameters of the pink stem borer, sesamia creticalederer (lepidoptera: noctuidae) were estimatedon its two main host plants, maize and sugarcane. the present studywas conducted under laboratory conditions at 27±1˚c, 50±10% relative humidity (rh %), and a photoperiod of 0:24 (l:d) hour for the larval stage and 16:8 (l:d) hour for the other life stages. the raw data were analyzed bas...

the life table parameters of schizaphis graminum (rondani) (hemiptera: aphididae) on four commercial cultivars of wheat (kohdasht, pastor, tajan and zagros) were determined in laboratory conditions. fertility life table were constructed using age-specific survivorship (lx) and age-specific fecundity (mx) and subsequently analyzed using jackknife method and anova. there were significant differen...

Control of the 2002-2003 severe acute respiratory syndrome (SARS) outbreak was based on rapid diagnosis coupled with effective patient isolation. We used uncertainty and sensitivity analysis of the basic reproductive number R0 to assess the role that model parameters play in outbreak control. The transmission rate and isolation effectiveness have the largest fractional effect on R0. We estimate...

The life history and predation rate were determined for all stages of female and male of Phytoseiulus persimilis Athias-Henriot fed on the eggs of Tetranychus urticae Koch ˗ as the preferred prey-stage ˗ on rose (cv ‘blarodje’) leaf discs under laboratory conditions at 25±1°C, 75±5% RH, and 16 L: 8 D hour photoperiod. According to the age-stage, two-sex life table model, the intrinsic rate of i...

the effect of temperature on demographic parameters of the greater wax moth, galleria mellonella (l.) was studied at 23, 25, 27, and 30 °c, 50 ± 10% rh and a photoperiod of 16:8 (l: d) h. the life table parameters were estimated according to the age-stage, two-sex life table procedure. in addition, the bootstrap technique was employed for estimating the means, variances, and standard errors of ...

The net reproductive rate R0 measures the expected lifetime reproductive output of an individual, and plays an important role in demography, ecology, evolution, and epidemiology. Well-established methods exist to calculate it from age- or stage-classified demographic data. As an expectation, R0 provides no information on variability; empirical measurements of lifetime reproduction universally s...

1. Second derivatives of the population growth rate measure the curvature of its response to demographic, physiological or environmental parameters. The second derivatives quantify the response of sensitivity results to perturbations, provide a classification of types of selection and provide one way to calculate sensitivities of the stochastic growth rate. 2. Using matrix calculus, we derive t...

ooencyrtus fecundus ferriere & voegele (hymenoptera: encyrtidae) is one of the gregarious egg parasitoids of sunn pest that can superparasitize the host. superparasitism has inverse effects on fitness, reproductive potential, competition ability and adult size of gregarious parasitoids. in this study, the effects of superparasitism and its intensity (four levels including singleton, twin, tripl...

The bifurcation that occurs from the extinction equilibrium in a basic discrete time, nonlinear juvenile-adult model for semelparous populations, as the inherent net reproductive number R0 increases through 1, exhibits a dynamic dichotomy with two alternatives: an equilibrium with overlapping generations and a synchronous 2-cycle with non-overlapping generations. Which of the two alternatives i...