Demography and Population Projection of Aphis fabae (Hemiptera: Aphididae): with Additional Comments on Life Table Research Criteria.

Abstract

We collected developmental, survival, and reproduction data for Aphis fabae Scopoli (Hemiptera: Aphididae) reared on faba bean, Vicia faba L. 'Sevilla' at four constant temperatures (15, 20, 25, and 30°C), 70% relative humidity, and a photoperiod of 16:8 (L:D) h. The highest intrinsic rate of increase (r = 0.4347 d(-1)) and finite rate (λ = 1.5445 d(-1)) were observed at 25°C. The population projection based on the age-stage, two-sex life table quantitatively revealed the growth potential and stage structure of the aphid. We have included the following suggestions to aid researchers in life table studies: 1) The bootstrap method should be used to estimate the variance and SEs of developmental time, survival rate, fecundity, and population parameters. 2) The required number of bootstraps is dependent on the life table data--the higher the variation among individuals, the higher the number of bootstraps should be. In most cases, we suggest that 100,000 bootstraps should be used to obtain a stable estimate of variance and SEs. 3) Computer projection based on the age-stage, two-sex life table should be used to reveal the stage structure during population growth. 4) We used a simple equation based on the total fecundity, survival rate to adult stage, and first reproductive age to detect possible errors in life table parameters. 5) To assist readers in comprehending results, life table studies should include the cohort size, preadult survival rate, number of emerged female adults, mean fecundity, survival and fecundity curves, and population parameters.