Effects of elevated CO2 on life-history traits of three successive generations of Frankliniella occidentalis and F. intonsa on kidney bean, Phaseolus vulgaris.
The objective of this study was to determine how elevated CO2 impacts on life-history traits and life table parameters in three successive generations of invasive species Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) and its related native species, Frankliniella intonsa (Pergande), fed with kidney bean leaves grown in ambient CO2. The oviposition period, sex ratio, net reproductive rate (R0), intrinsic rate of increase (rm), and finite rate of increase (λ) of F. occidentalis increased in elevated CO2, and larval duration, survival rate, mean generation time (T), and population doubling time (DT) decreased. For F. intonsa, larval duration, survival rate, oviposition period, longevity of female adults, R0, rm, and λ decreased in elevated CO2, whereas sex ratio, T, and DT increased. These results indicated that the effects of elevated CO2 would be beneficial to F. occidentalis, whereas it would be detrimental to F. intonsa. However, the effects of elevated CO2 on F. occidentalis and F. intonsa differed over generations. In elevated CO2, larval duration, survival rate, oviposition period, sex ratio, rm, and λ of F. occidentalis increased linearly through successive generations, whereas T and DT decreased linearly, which suggested that the effects of elevated CO2 on F. occidentalis would be slowly accentuated over time. For F. intonsa, larval duration, survival rate, oviposition period, rm, and λ decreased linearly over generations, whereas sex ratio, T, and DT increased linearly. This indicated that the effects of elevated CO2 on F. intonsa would slowly accentuate over time. We conclude that F. occidentalis would be more adapted to elevated CO2 than F. intonsa.